Egan’s Chapter 8 Practice Questions:

1. 2 types of pulmonary arteries 1. Conventional arteries
2. Supernumerary arteries
2. 2 umbilical arteries carry blood from the fetal aorta to the placenta to carry out: fetal-maternal gas and nutrient exchange.
3. 3 embryologically distinct germinal tissue layers *Ultimately form all tissues and organs
*Include:
* endoderm
* Mesoderm
* Ectoderm
4. 3 imaginary verticle lines located on the posterior thorax 1. Midspinal Line : divides posterior into 2 equal halves
2. Left mid scapular line
3. Right mid scapular line
5. 4th Phase
The Terminal Saccular Stage
*More Terminal bronchioles & their associated acini form.
*the total number of terminal bronchioles completes at the end of phase 4
*The cuboidal epithelial cells that line the blind tubules of the acinus continue to differentiate into:
* rounded secretory cells (type II pneumocytes)
* and flatter epithelial cells (Type I pnumocytes)
6. Abdominal compression forces the diaphragm upward, compressing the thoracic cavity.
7. Abdominal Muscles
8. Abdominal muscles are ______ during rest and forceful exhalation. active
9. Abdominal muscles become more active when: The elastic recoil of the lung and thorax cannot provide the needed expiratory flow during forceful inhalation such as:
coughing Sneezing *Talking loudly
* playing wind-powered Instruments
10. The abdominal muscles include pairs of: 1. External obliques
2. Internal Obliques
3. Transverse abdominis
4. Recutus abdominis muscles.
11. Acessory Muscles of Breathing *muscles of the neck, back, and abdomen that may assist the diaphragm and the internal and external intercostal muscles in respiration, especially in some breathing disorders or during exercise
12. Acetylcholine binds to M3 muscarinic cholinergic receptors and causes airway smooth muscle constriction, blood vessel dilation, and glandular secretion
13. Acinus The gas-exchanging unit of the lung.
14. The acinus (primary lobule) of the lung is composed of a single terminal bronchiole, numerous respiratory bronchioles, alveolar ducts, sacs of alveoli, and about 10,000 alveoli. Pulmonary blood flow is delivered to the acinus by a pulmonary arteriole and drained from it by a pulmonary venule
15. Additional receptors are located outside the lungs; they include respiratory muscle proprioceptors that sense the stretch state of the muscles and peripheral chemoreceptors that sense the chemical condition of blood that are involved in the control of ventilation
16. The adventitia is a sheath of connective tissue that surrounds the airways It is interspersed with bronchial arteries, veins, nerves, lymph vessels, and adipose tissue. Between the submucosa and adventitia of the large airways are incomplete rings or plates of hyaline cartilage, which provide structural support for the larger airways. The small airways depend on transmural pressure gradients and the “traction” of surrounding elastic tissues to remain open. During a forced expiration, pressures across the walls of the small airways exceed the supporting forces of the elastic tissues. As a result, the small airways can collapse. The cartilage in the larger airways prevents their collapse during such maneuvers.
17. After forming ganglia and postganglionic nerve fibers, parasympathetic and sympathetic nerve fibers enter the lung through the hilum and run parallel to the airways as they branch
18. The airways from the nares to and including the terminal bronchioles constitute the conducting zone airways, which do not participate in gas exchange. These airways constitute the anatomic dead space of the respiratory system, which is rebreathed with each breath.
19. Airways of the conducting (generation 0 through 16) and respiratory (generation 17 through 23) zones: T, trachea; B, right and left bronchi; LB, lobar bronchi; SB, segmental and subsegmental bronchi; BR, bronchioles; TB, terminal bronchioles; RBL, respiratory bronchioles; AD, alveolar ducts; and AS, alveolar sacs
20. Alae -two flared openings
-form the external nares
-alae enclose a space on each side called the vestibule
21. All development of the airway is complete by ____years of age with most development completing in the first _____ years. 10

1.5

22. All of the airways down to and including the terminal bronchioles carry or conduct gas flow to and from the airways that participate in gas exchange with blood.
23. All of the conducting airways from the trachea to the bronchioles have walls that are constructed of three layers an inner layer that forms a mucous membrane called the mucosa, which is primarily composed of epithelia; a submucosa composed of connective tissue, bronchial glands, and smooth fibers that wrap around the airway; and an outer covering of connective tissue called the adventitia.
24. Altered development of smooth muscle cartilage and vascular structures can lead to : *congenital pulmonary disorders such as:
*tracheomalacia
* anomalous pulmonary arteries
*Vascular rings that grown around and pinch
the airway
25. Alveolar Stage 32th-40th wk:
Immature alveoli begin to form and increase in number; surfactant production matures40th week:
50 million immature alveoli formed
26. alveoli tiny sacs of lung tissue specialized for the movement of gases between air and blood
27. alveoli small outpouchings
The alveoli and their pulmonary capillary bed enable the respiratory bronchioles to carry out gas exchange. The respiratory bronchioles constitute a transitional zone type of airway.
28. The amount of cartilage supporting the airway: decreases as smooth muscle cells (in the middle layer of the airway) increase in number.
(2nd Phase)
29. Anatomic Closure of the ductus normally occurs within 3 weeks of birth
30. Anatomic Reference lines
31. “Another reflex that is associated with SAR and RAR activity is the.. Head paradoxical reflex-This reflex stimulates a deeper breath rather than inhibiting further inspiration.
-It may be the basis for occasional deep breaths or gasps
32. Anterior and lateral views of the larynx
33. Anterior Axillary *Parallel to the midaxillary line
*Situated along the anterolateral chest
34. The anterior portion is covered with stratified squamous cells and possesses hair follicles and hair. This is the same type of tissue that forms the epidermis of skin
35. Anterior view of the bones of the thorax
36. Anterior view of the lungs shownig lobes and fissures
37. Apices Upper most portion of the lungs
38. apoptosis programmed cell death
39. Approximately _______ of blood flows to the lower trunck and extremities 1/3
40. Approximate Normal Values of Blood Gases & Acid-Base in fetal and Maternal Blood Value MIB FUAB FUVB
PH 7.38 7.36 7.39
PCO2 42 47 43
PO2 50 19 30
MIB- Maternal Intervillous Blood
FUAB- Fetal umbilical Artery Blood
FUVB- Fetal Umbilical Venous Blood
41. ____________ & ______________ are formed long before birth and are the primary components of the somatic (motor) nervous stystem that carries nervous signals from the brainstem to the respiratory muscles Pherenic Nerves & Intercostal Nerves
42. Assessment of umbilican vein blood gas data shortly afer birth is a method of determing the degree of fetal asphyxiation during the birth process.
43. As systemic vascular resistance increases left-sided heart pressures increase.

*left arterial pressures also increase as a result of increased pulmonary blood flow that returns from the lungs.

44. As the bronchi form: *plates of cartilage develop from the surrounding mesoderm to support these airways
*During this period, the vascular components of the respiratory begin to develop from the mesoderm.
(1st Phase)
45. A)Superior view of true vocal cords, glottis (rima glottidis), epiglottis, and other structures within the larynx.
B) Endoscopic photograph showing vocal cords in the open position
46. At 2.5 to 3 months of age anatomic decent of the epiglottis begins
47. At approximately 4 to 5 months of age, most infants are capable of full oral ventilation
*up to this point infants ofter breathe through their nose
*most term newborn infants shift to oral breathing in response to nasal occlusion and hypoxia
48. At birth, approximately ______% of circulating hemoglobin is HbF. 70%
*HbA gradually replaces HbF during the first 6 months of extrauterine life as HbA genes in bone marrow switch on and HbF genes in the liver are switched off.
49. At Birth the Lungs go from being a liquid-filled organ that possesses very little circulation and is incapable of sufficient gas exchange to an air-filled organ that recieves the entire cardiac output from the right heart and caries out all of the necesary gas exchange to sustain life.
50. At rest, the pulmonary capillary bed contains 60 to 80 ml of blood and can expand to 200 ml through dilation and recruitment of collapsed capillaries during conditions of higher cardiac output
51. At Term the fetal lung: *Is filled with about 40ml
*fluid is produced @ the rate that resules in replacing it multiple times per day.
52. At the end of expiration the anterior low borders extend to approximately the sixth rib at the midclavicular line.
53. At the end of phase 3 if the fetus is born: *It is capable of sufficient gas exchange and is viable if supported with:
*Supplemental O2
*Ventilatory Support
* Surfacant Administration
54. Autonomic innervation of the lungs is carried from the brainstem through branches of the right and left vagus nerves (cranial nerve X) and from the spinal cord to four or five thoracic sympathetic ganglia that lie just laterally to the spinal cord
55. The autonomic nervous system signaling to and from the lungs is carried through efferent and afferent pathways. These pathways carry unconscious autonomic nervous system motor signals to smooth muscles and glands and various sensory signals back to the
56. Below the basement of the epithelia grow: *smooth muscle cells
*connective tissue
*blood vessles
(2nd Phase)
57. The better oxygenate blood in the inferior vena cava: *mixes with the venous blood returning from the lower trunk and extremities and enteries the right atrium.
*Approximately 50% of this blood is shunted from the right atrium into the left atrium through an opening in the interatrial septum (foramen ovale)
58. The blood-gas barrier is not equal in thickness and chemical content from side to side On one side of the alveolar wall, the type I cells and capillary endothelial cells lie close together with a thin interstitial space. This part of the blood-gas barrier is, on average, 0.2 to 0.3 µm thick, and it is where the alveolar capillary bulges into the alveolar space.103 On the other side, where there is a thicker interstitial space with greater fiber, matrix, and nuclear material content, the barrier can be more than 3 to 10 times thicker. This difference between the two sides functionally results in “faster-weaker” and “slower-stronger” diffusion sides of the blood-gas barrier.
59. Both sympathetic and parasympathetic postganglionic efferents innervate the smooth muscle and glands of the airways and the smooth muscles of the pulmonary arteriole
60. Breathing of a Newborn Infant Placental gas transfer is suddenly interrupted, the newborn quickly becomes hypoxemic, hypercapnic, and acidotic. This situation triggers strong inspiratory efforts
*At first, no air enters the newborn lung until the transpulmonary pressure gradient exceeds 40 cm H2O.
*As lung volume increases in a stepwise fashion with each breath, increasingly less pressure is needed to overcome the opposing forces.
*The volume trapped in the lung stabilizes quickly and is crucial to adequate gas exchange.
61. Bronchial and Bronchiolar Divisions
62. The bronchial and pulmonary circulations share an important compensatory relationship. *Decreased pulmonary arterial blood pressure tends to cause an increase in bronchial artery blood flow to the affected area.
*This compensation minimizes the danger of pulmonary infarction, as sometimes occurs when a blood clot (pulmonary embolus) enters the lung.
63. bronchial circulation supplies blood to the airways from the trachea to the bronchioles and to most of the visceral pleurae.
64. The broncial arteries supply O2 to: * Airway Tissue
*Blood Vessels
*Nerves
*Lymphatics
*Visceral Pleura
65. The broncial buds continue to grow and branch into secondary bronchi that form: *lobar
*segmental bronchi
*subsegmental bronchi
(1st Phase)
66. Canalicular Stage 16th-17th wk: Respiratory bronchioles and immature acini begin to form

20th-24th wk:Type I and II pneumocytes begin to appear and replicate

24th-26th wk:Pulmonary capillaries develop at surface of acinus, immature surfactant begins to appear in lung fluid

67. canals of Lambert openings connect alveoli with secondary respiratory bronchioles
68. The capillary wall is formed from thin, flat squamous epithelia called endothelial cells that form a thin tube by connecting together at their edges with tight junctions.
69. Carina bifurcation of the trachea into the right and left main stem bronchi.
70. Cause of prolonged apnea and sudden infant death syndrome *The protective laryngeal closure caused by the development of mechanical and chemical laryngeal reflexes at birth.
*Infections in this area or repeated attempts at intubating or suctioning can cause swelling and obstruction on this area (Upper airway)
71. The centrally located mediastinum contains: 1. trachea
2.esophagus
3. heart
4. great vessels
5. Other organs
72. C-fiber activation has also been shown to cause bradycardia, hypotension, bronchoconstriction, mucus production, and apnea
73. Ciliary beating can be effectively slowed or stopped if the viscosity of the sol layer is increased by exposure to dry gas. Ciliary motion is also slowed or stopped after exposure to smoke, high concentrations of inhaled O2, and drugs such as atropine.
74. ciliated pseudostratified epithelia play a crucial role in the defense of the respiratory tract by propelling mucus toward the pharynx.
75. Clara cells nonciliated cuboidal cells with apical granules, are found. It is thought that these cells play a role in degrading various xenobiotic oxidants via cytochrome P-450, contribute proteins for surfactant production, synthesize various lipids, and play a role in lung repair by being able to differentiate into other important epithelial cells in the mucosa after injury
76. Conditions that lead to reduced fetal breathing and amniotic fluid formation are linked to incomplete inflation of the lung with fluid and poorly developed (hypoplastic) lungs.
77. these connective tissue fibers function to provide: support to the airway walls, lungs, and effective gas exchange membrane as it is stretched during inflation.
78. Conventional Arteries Continue to follow the airway branching
79. Costal Cartilage *Cartilage Joint
*on the lateral edges of the maubrium and sternal body that forms the attachment between the ribs and the sternum
*This Joint Allows the ribcage to bend and permits the thorax to increase and decrease in size.
80. Costophrenic angle *The angle where the costal parietal pleura joins the diaphragmatic parietal pleura.
*Located in the right and Left lateral & inferior regions of the thoracic cavities.
*important landmark in normal chest radiograph
*Sharp Angle 30-45 degrees
81. Course of trachea and right and left main stem bronchi, superimposed on a standard chest radiograph. The right main stem bronchus continues on a straighter course from midline than the left main stem bronchus
82. Cricoid Cartilage the only laryngeal structure that forms a complete ring of cartilage around the airway and is the most narrow region of the upper airway in infants
83. Cricoid Cartilage *ring of cartilage connecting the larynx and trachea
*In Children this is the narrowest region of the upper airway
84. Cricothyroid ligament A membrane of connective tissue
85. Critical role of lymphatic vessels control fluid and protein belance within the lung and house various defensive cells.
86. Cross-sectional view through a bronchiole
87. Cross-sectional view through the trachea and esophagus
88. Dermis a composite of an outer epidermis and inner connective tissue (skin)
89. The developmental phases between fertilization and birth are generally divided into 2 stages 1. Embryonic Period
2. Fetal Period
90. Diagram of internal and extrnal intercostals
91. Diagream of the Trapezius muscles
92. Diaphragm large dome-shaped muscle that separates the thorax from the abdomen; the primary muscle of ventilation
*thin, musculotendinous
*originates from the chest and abdonminal wall and converges in a central tendon @ the top of its dome.
93. The diaphragm doesn’y actively participate in: exhalation
*During exhalation, it returns to its resting position during the passive recoil of the lungs and thorax.
94. the diaphragm is divided into a right and a left hemidiaphragm. Each hemidiaphragm is innervated by a phrenic nerve that arises from branches of spinal nerves C3, C4, and C5
95. The diaphragm rises and falls with resting breathing between the 9th and 12th thoracic vertebrae
96. Dichotomous Branching the process of airways dividing into 2 or more airways
(2nd Phase)
97. A distinctive function of the developing lung is : the formation of relatively large amounts of fetal lung fluid that is passed into amniotic fluid.
98. The distribution of pulmonary blood flow is also closely related to local airway gas pressure and pulmonary gas exchange. *Areas that experience higher airway pressure that equals or exceeds local arteriole and capillary pressure have reduced blood flow as a result of the opposing airway pressure (zone 1 airways).
* Regions where blood pressure is greater than the surrounding air pressure, such as in the bases of the upright lung during spontaneous breathing, have greater blood flow (zone 3 airways).
99. The dorsal portion of the primitive foregut develops into the primordial esophagus and is separated from the tracheal bud by the formation of a tracheoesophageal septum.
(1st Phase)
100. Ductus Arteriosus a blood vessel in a fetus that bypasses pulmonary circulation by connecting the pulmonary artery directly to the ascending aorta
101. Ductus Artriosus *Caused by the low PO2 and various prostaglandins in fetal blood
*A muscular vessel attached to the trunk of the pulmonary artery and the aorta to dialate and the pulmonary arteries constrict leading to increased pulmonary vascular resistance and higher artery pressure than aortic blood pressure.
102. Ductus Venosus *2/3 of blood flows through here.
*the fetal structure that allows most of the blood to bypass the liver and to flow from the umbilical vein to the vena cava
103. During expiration scalene muscles are largely inactive but can become active to fixate the ribs as abdominal muscles contract during forceful exhalation such as coughing
104. During Maximal inspiration the diaphragm can be pulled down approximately 10cm.
105. During normal vaginal delivery, approximately _____ of the lung fluid is cleared through compression of the thorax in the birth canal. 1/3

*the remaining fluid is cleared by pulmonary capillaries and lymphatics

106. During Quiet Breathing *the diaphragm does most of the work.
*Other muscles are slightly active during quiet breathing and beome more active with forceful breathing.
107. During swallowing the infant’s larynx provides a directo connection to the ______. Nasopharynx
*This connection creates 2 seperate pathways:
1. one for the infant to breathe
2. One for the infant to swallow.
*This allows infants to breathe and suckle at the same time.
108. During week 5 of development the tracheal bud continues to develop and bifurcates into left and right ptimary bronchial buds.
(1st Phase)
109. dynein protein filaments that extend toward the adjacent pair of microtubules
110. each acinus is equipped with a lymphatic drainage vessel and nervous fibers. These features make the primary lobule the functional unit of the lungs. Gas molecule movement in this region is largely via diffusion rather than convective flow, which occurs in larger airways.
111. Each acinus is supplied with pulmonary blood flow from a pulmonary arteriole, and blood is drained away from several acini through a pulmonary venule.
112. Each lung is divided into how many lobes? Right Lung: 3 lobes:
Upper
Middle
Lower
Left Lung: 2 Lobes
Upper
Lower
113. Each Rib Has 1. A sternal end
2. A long curved and flat body
3. a head that articulates with the thoracic vertebrae
114. Embryonic Period Embryonic Period

20-22 days: Primordial pharyngeal arches form
21-23 days: Primordial respiratory cells form on fourth pharyngeal pouch, primordial heart starts forming
26th day: Laryngotracheal bud forms
4th wk:Primitive trachea develops
5th wk:Primary bronchial buds form, laryngeal structures develop

115. The embyonic Period * Occurs during the first 8 weeks
*Is traditionally organized into 23 stages known as the Carnegie Stages
*During this time all major organs begin developing.
116. Emphysema is a disease characterized by: the destruction of the alveolar region of the lungs
*This destruction causes the emphysematous lung to have less elastic recoil than normal
117. Epiglottis *flap of tissue that covers the trachea during swallowing, preventing food from entering the lungs
*flat cartilage that extends from the base of the tongue backward and upward.
118. Epiglottis in an infant vs adut Infant: longer epiglottis and less flexible & lies higher and in a more horizontal position that that of an adult.
119. Epinephrine and norepinephrine bind to alpha-adrenergic receptors of blood vessels to cause constriction and to beta-adrenergic receptors of the bronchial airway and vessel smooth muscles to cause relaxation and dilation of the airways and blood vessels
120. The epithelial lining of the airways *begins to differentiate into columar epithelia in the proximal airways & differentiated into cubodial epithelium in the more distal bronchioles.
(2nd Phase)
121. Epithelium lining layer *forms the mucous and gas exchange membranes of the entire respiratory system arises from the endoderm
122. Exchange of Oxygenated Fetal Blood Oxygentated fetal blood leavess the chorionic villi capillaries through placental venules and returns to the fetus through a single umbilical vein.
123. Exhalation results when diaphragmatic tension decreases, and the diaphragm returns to it’s relaxed position.
124. External intercostal muscles Originate: on the upper ribs &
Attach:to the lower ribs
125. External intercostals are more active during * the inspiratory phase of forceful breathing and are thought to play a role in stabilizing excessive rib motion during forceful breathing
126. The external intercostals fibers and tension **The fibers of these muscles run at an oblique andgle between the ribs
*When they generate tension, they lift the ribs upward and cause the thoracic cavity to enlarge the thorax.
* They receive nerve signals from the intercostal nerves that arise from thoracic spinal nerves (T1-12).
127. The external obliques *the outermost layer of abdominal wall muscle and lie over the lateral aspects of the abdominal cavity.
128. External obliques originate________ & Inserts_______. Originates: on the anterior surface of the lower 8 ribs and abdominal aponeurosis
Insert: into the linea alba, illiac crest, and inguinal ligament.
129. Factors for much lower PO2 level in fetal blood compared to adult blood include:
(The O2 content is almost the same in fetal and adult blood)
*realitively higher content of hemoglobin (18g/dl) in fetal blood
*higher hematocrit (54%) in fetal blood
*Presence of fetal hemoglobin (HbF)
130. Failure of key genes associated with normal surfactant production
(genes A, B, C, & D)
is linked with the development of respiratory distress syndrom and other pulmonary disorders.
131. Fetal blood that enters the villi has a PO2 of: approximately 19mmHg
*The pressure gradient between maternal and fetal blood PO2 (50-19=31mm Hg) causes O2 to diffuse in fetal blood.
132. Fetal Lung Fluid is: *Fetal lung fluid is a unique combination of plasma ultrafiltrate from:
* the fetal pulmonary microcirculation,
*components of pulmonary surfactant,
* other fluids from pulmonary epithelial cells.
* This fluid is constantly produced and keeps the fetal lung inflated at a slight positive pressure with respect to amniotic fluid pressure; it is important in stimulating normal lung development.
133. The Fetal Period * Occurs during the remaining 32 weeks of gestation.
*Organs continue to grow and refine their structure and function.
134. Fetal Period
Pseudoglandular Stage
6th wk:Segmental and subsegmental bronchioles form
7th wk:Diaphragm complete
8th wk:Heart complete, fetal circulatory pattern begins to develop
10th wk:Pulmonary lymphatic structures develop
12th wk:Major arteries formed
13th wk:Major airway epithelia and mucus-producing cells formed, smooth muscle cells developing
14th wk:Principal arteries formed
16th wk:Terminal bronchioles and associated pulmonary vessels form
135. Fetal Respiratory Effots *begin during midgestation and continue until birth.
*during these efforts the fetus moves little or no fluid in and out of the lungs.
*The rhythm and depth of fetal breathing are periodic and irrgular and reflect the development of the respiratory center in the brain and respiratory muscles.
136. The fibers within the alveolar septum are part of the continuum of connective tissue fibers that are found in the pleural surface and in the airway walls that extends all the way to the root of the lung in the hilar region. Elastin and collagen fiber bands are formed by fibroblasts into a network within the interstitial space into which the capillaries are woven. Also around the fibers and capillaries is a nonliving matrix of fluid and solutes. The weaving path taken by the capillaries passes them from the thick to the thin sides of the blood-gas barrier as they extend through the septum. In the thin side, the basement membranes of the endothelial and type I cells fuse into a structure called the lamina densa, which is formed from type IV collagen
137. Filtration is based on impaction, sedimentation, and diffusion of various sized particles
138. Final Phase of Lung Development
Alveolar Period
*mature alveoli, accompanied by capillart proliferation within the walls develop.
*Terminal saccules develop like pouchlike regions called alveoli in their walls that are hexagonal in shape.
139. Fissures *narrow clefts or slits;
* the lines that divide or separate the lobes of the lung glottis
140. The floor of the cavity (palate) is primarily formed by the maxilla
141. Foramen Ovale Opening in the interartial septum.
142. The foramen ovale closes due to left-sided heart pressures that are now higher than right-sided pressures.
143. Four major pulmonary veins superior and inferior veins from each lung—exit through the hila and return arterialized blood to the left atrium of the heart for delivery to the systemic circulation
144. From Phase 4 to Birth: * there is rapid proliferation of alveolar ducts and sace formed from the respiratory bronchioles.
145. Frontal view into the open mouth showing the major structures within
146. Functions of the Upper Airway •Passageway for gas flow
•Filter
•Heater
•Humidification
•Sense of smell and taste
•Phonation
•Protection of the lower airways
147. Functions of thr Right and Left Heart Right: supplies the bulk of the flow to the pulmonary circulation

Left: supplies a smaller amount of flow to the bronchial arteries, which arise form the aorta and supply oxygenated blood to the tracheobronchial tree.

148. Gas exchange between alveolar gas and pulmonary capillary blood occurs across alveolar-capillary membrane. In a typical adult, this blood-gas barrier stretches over a surface area of approximately 140 m2 and is less than 1 µm thick over most of that area.103 This makes the membrane more than 50 times larger than the area covered by skin and more than 2000 times thinner.
149. gel layer The outer layer of mucus is more gelatinous
150. Gladiolus the body of the sternum.
151. Glottis opening between the vocal cords in the larynx
*In adults this is the narrowest region of the upper airway
152. Hard palate -The anterior roof of the oral cavity
-formed by the maxillary bone
153. Highly magnified cross-sectional sketch of the cells and organization of the alveolar septa
154. Hilum *vertical opening on either side of the mediastinum through which all the airways and pulmonary vessels pass.
*The main stem bronchi, blood vessels, lymphatics, and nerves that enter or exit the lung all pass through the hilum.
155. Histamine causes vasodilation and bronchoconstriction, acting directly on smooth muscle.
156. Histologic diagram of airways from the segmental bronchus to the alveolus
157. Horitontal or “minor” fissure *found in the right lung only
*Seperates the middle and upper lobe
*extends from the fourth rib at the sternal border to the fifth rib at the midaxillary line.
158. hree different fiber systems form a scaffold that supports the structure of the lungs as tension develops in them with inflation. 1. The axial system, primarily composed of collagen and reticulin fibers, originates in the hilum and extends outward in all of the airway walls almost all the way to the alveolar region.
2. The septal fiber system, composed of collagen, reticulin, and elastin, supports the alveolar walls and capillaries.
3. The peripheral fiber system, primarily composed of collagen, originates in the outer viscera and extends into the lung tissue to divide up the lung tissue effectively into interlobular regions.
159. Human PULMONARY SURFACTANT *Promotes lung inflation & protects the alveolar surface
*Begins to be produced atround 24&25 weeks of development by type I&II pneumocytes
*composed primarily of:
*phospholipids
*small amount of protein
*Trace of carbohydrates.
160. Hypopharynx -region below the oropharynx
-it extends from the upper rim of the epiglottis to the opening between the vocal cords
-below the hypopharynx, the digestive and respiratory tracts separate
161. Important functions of the diaphragm other than ventilation *aids in generating high intrabdonminal pressures by remining fixed while the abdominal muscles contract, facilitating vomiting, coughing, sneezing, defecation, and parturition.
162. Importants of Cranial Nerve X
(The Vagus Nerve)
caries motor and sensory signals of the parasympathetic system.
163. Increased cross-sectional area . reduces the velocity of gas flow during inspiration.
164. inflation reflex Pulmonary stretch SARs and RARs progressively discharge during lung inflation and are linked to inhibition of further inflation
165. Injury to the embryo during this phase of development *Can lead to many congenital anomalies including:
*tracheoesphageal fistulas
* esphageal artresia
* choanal artresia
* Pulmonary hypoplasia
* Complex heart & vascular anomalies
(1st Phase)
166. In Phase 4 the Type II pneumocytes of the saccule walls *thin and elongate to cover the walls of this region
167. interconnection of pulmonary and bronchial circulations.
1. Bronchial blood flows to the pulmonary artery
2. through the capillary bed of the large airways and pleura and into pulmonary capillaries
3. through the bronchopulmonary veins and into the pulmonary veins
4. through the bronchial vein and on to the azygos vein
* The route through the bronchopulmonary vein allows less oxygenated blood to mix with the better oxygenated blood, which returns to the left side of the heart.
168. Intercostal Nerves Nerves between the ribs that aid in inhalation and relaxation, skin of thorax region, abdominal wall
*Intervate the intercostal muscles
169. The internal branch provides sensory fibers to the larynx
170. Internal Intercostals muscles *lie between the ribs and behind the external intercostal muscles
*compress the thoracic cavity by pulling together the ribs.
*Muscle fibers run downward and less obliquely thant External intercostals.
171. The internal Intercostals originate________ and and insert_____? Originate:along the inferior boarder of the upper ribs
Insert: into the superior boarder of the lower ribs.
*Most active during forceful exhalation
*Become active toward the end of deep inhalation and act to antagonize the lifting effect of the external intercostals which stablizes rib motion during forceful exhalation
172. internal nares -The posterior openings of the nasal cavity
-are formed in part by the flexible soft palate
173. Internal Obliques *Lie just under the external obliques.
174. The internal obliques originate ___________ & Insert _____________. Originate: on the lumbar vetebrae, illiac crest, & inguinal ligaments
Inserts: into the pubis and costal regions of the lower ribs.
175. In the last several weeks of phase 3 *The region beyond each terminal beonchiole froms the functional structure called the acinus.
*the 2 principal epithelial cell types that cover gas exchange surface begin to appear:
*Type I pneumocytes
*Type II pneumocytes
176. In the mucosal layer of the airway rapid adapting receptors (RARs) sense changes in tidal volume, respiratory rate, and changes in lung compliance and respond to a wide variety of mechanical and chemical
177. In the thick side, thick bands of type I collagen and elastin are found. The type I cells and endothelial cells are attached to either side of the lamina densa by a series of protein fibers collectively known as laminins Laminins effectively bind together the blood-gas barrier into a three-part laminate that results in a relatively strong and thin structure that can normally, with the additional support offered by the capillary network, withstand the everyday stress of alveolar and capillary stretch.
178. Irritant or mechanical RARs are found mainly in the posterior wall of the trachea and at bifurcations of the larger bronchi. These receptors respond to various mechanical, chemical, and physiologic stimuli and behave as irritant receptors
179. It is essential for a newborn to develop high transpulmonary pressure gradients during the first few breaths to: open and replace the remaining lung fluid with air and establish a lung volume for gas exchange.

*The stimulus for these initial respiratory efforts is sent via peripheral and central cehmoceptors and augmented further by skin thermoceptors.

180. junctions prevent the movement of fluids and electrolytes between the apical surface and basal surfaces of the airway.
181. Just below the mucous membrane -is an extensive network of veins that form a venous plexus. These vessels supply water and heat to the gas within the nasal cavity
– Inflammation of this mucous membrane is brought on by irritation or infection
182. juxtacapillary or J receptors also known as.. Unmyelinated slow-conducting C-fiber endings
-present in the walls of the bronchial and terminal airway region
-have been linked to a breathing reflex pattern associated with mechanical stretch, pulmonary congestion, and exposure to various chemicals
183. The laryngeal structures develop at the superior end of the laryngotracheal bud
(1st Phase)
184. The laryngotracheal tube *forms from a groove in the 4th pharyngeal pouch.
*from this a tracheal bud forms by the end of the 4th week of life.
(1st Phase)
185. Larynx -lies below the hypopharynx and is formed by a complex arrangement of nine cartilages and numerous muscles
-it functions to protect the respiratory tract during eating and drinking and in phonation
186. Laterally, the lower lung boarder is at the eighth rib at the midaxillary line.
187. The lateral walls are created by the maxilla, lacrimal, and palatine bones
188. Layngeal Barking The narrowing of the glottis or larynx during exhalation
189. The left and right nasal cavities are formed by cartilage and numerous skull bones
190. The left and Right pleural cavities contain: The Lungs
191. Left atrial blood flows to the _______ ______ and then to the _______ ______ where it cominues onto the brain, brachiocephalic trunk, and decending aorta. Left Ventricle

Ascending Aorta

192. Located posterior to the vestibules are the openings to the internal nose, or the anterior nares
193. Loss of effective use of the abdominal wall muscles results in : an inability to exhale forcefully and cough effectively. (common in COPD patients)
194. The low vascular pressures of the pulmonary circulation result in regional blood flow within the lungs that is highly influenced by gravity, airway pressure, and gas exchange.
195. The low vascular pressures within the pulmonary circuit are essential in : *maintenance of fluid balance at the alveolar-capillary interface.
The pulmonary capillaries are exposed to vascular pressures of about 7 to 10 mm Hg. Increased pressure in the pulmonary circulation, which can occur with mitral valve disease or congestive heart failure, can disrupt fluid balance and lead to excessive fluid leakage, fluid accumulation, and alveolar congestion, which can impair gas exchange and lead to hypoxia.
196. Low-velocity gas movement at the level of the terminal bronchiole and beyond is physiologically important for two reasons. First, laminar flow develops, which minimizes resistance in the small airways and decreases the work associated with inspiration. Second, low gas velocity facilitates rapid mixing of alveolar gases. This mixing provides a stable partial pressure of O2 and CO2 in the alveolar environment that supports stable diffusion and gas exchange.
197. Lung elasticity stems from surface tension forces in the alveoli and from the elastic properties of the tissues and various connective tissue fibers.
198. Lung Fluid Days before Birth *is stopped by the epithelia of the lung.
*The actively abosrbed back into the fetal circulation.
199. Lung Growth in Male and Female fetuses *Similar
*@ birth lungs of male infants are typically larger and have more respiratory bronchioles.
*@ 26-36 weeks female fetuses have bettr developed lung function and are slightly less suceptible to the development of Respiratory distress syndrome.
200. Lungs * multilobed, cone-shaped, spongelike organs that lie within the pleural cavities
* pink at birth and develop a gray coloration with age.
*Average adult lungs are hollow low-density organs that occupy a volume of approximately 3.5 L and weigh approximately 900 g.
201. The lungs also play an active role in : *the clearance and activation and release of various biochemical factors.
* They are responsible for synthesis, activation, inactivation, and detoxification of many bioactive substances.
202. Lung size and volume in men and women Boys/Men: tend to have higher lungs that age-matched and height-matched girls/women
203. Lung Volume of an an infant *Lung volume is reduced in infants
*Proportionately lower lung volumes in an infant can lead to:
*early airway closure
*widespread alveolar collapse (atelectasis),
*ventilation/perfusion mismatch
*resultant hypoxemia.
*The combination of a reduced lung volume and high O2 consumption in an infant renders the infant more susceptible to profound hypoxemia in situations that disturb ventilation, lung volume, or matching further.
*Infants, especially infants in distress, can actively increase lung volume by trapping gas, which improves matching and gas exchange.
204. The lymphatic system also plays an important role in the specific defenses of the immune system. *It removes bacteria, foreign material, and cell debris via the lymph fluid and through the action of various phagocytic cells (e.g., macrophages) that provide defense against foreign material and cells that are able to penetrate deep into the lung.
*It also produces various lymphocytes and plasma cells to aid in defense.
*Both roles are essential for maintaining normal function of the respiratory system
205. The lymphatic system of the lungs is an extensive system of : lymphatic vessels, lymph nodes, the tonsils, and the thymus gland.
206. Macrophages are another common cell found in the alveolar region. They can move from the pulmonary capillary circulation by squeezing through openings in the alveolar septa and then move out onto the alveolar surface. They are defensive cells that patrol the alveolar region and phagocytize foreign particles and cells (e.g., bacteria). They can present portions of the foreign particles and bacteria to lymphocytes as part of the immune response and contain various digestive enzymes (e.g., trypsin) that break down the material they engulf.
207. Major airways of the tracheobronchial tree
208. Major and Minor Pectoralis Muscles *Broad fan-shaped muscles of the upper anterior chest.
* when they recieve impulses from the pectoral nerves, they adduct the arms in a hugging motion.
*Also capable of generating some anterior thoracic lift when the arm are braced on a surface infront of a subject.
209. Major Cardiopulmonary Changes That Occur During Transition from a Fluid-Filled lung to and air-filled lung *As the lung expands with air, and gas exchange starts within the lung, pulmonary blood PO2 increases, PCO2 decreases, and pH increases;
*this results in pulmonary vasodilation, lower pulmonary vascular resistance, and constriction of the ductus arteriosus, which facilitates greater blood flow through the pulmonary circulation.
*Ductus arteriosus closure is stimulated further by the loss of maternal prostaglandins
*The Combination of increasing alveolar air content and constriction of the ductus arteriosus promotes progressive improvement in the matching of ventilation and blood flow, which increases the PO2 and decreases the PCO2 of blood leaving the lungs
210. Manubrium upper triangular portion of the sternum
211. Mast cells release numerous and potent vasoactive and bronchoactive substances such as histamine
212. Maternal and Fetal blood remain seperated by: an embryonic membrane that permits the exchange of:
O2 Ions
CO2 Various metabolic pressures
Water Hormones
213. Maternal Blood has a partial pressure of O2 (PaO2) of approximately 100mm Hg which mixes with the blood in the intervillous space to produce a mean PO2 of approximately 50mm Hg.
214. The maternal blood flowing through the intervillous spaces: *bathes the embryonic villi resulting in an increased surface area that is essential for adequate maternal-fetak fas, nutrient, and waste exchange.
215. Maternal Blood Flows into:

Fetal Blood is supplied:

*intervillous space through spiral arteries

*the villi from 2 umbilical arteries.

216. Maxillary Line divides the lateral chest into equal halves
217. Medial Surfaces of the lungs
218. Mediastinum *Lies between the Left and Right pleural cavities that contain the lung.
219. The mediastinum is bounded on either side by : the pleural cavities
anteriorly by the sternum,
posteriorly by the thoracic vertebrae
inferiorly by the diaphragm,
and superiorly by the thoracic inlet.
220. Mesoderm-derived cartilige provides: *Rigidity
(especially for the trachea and main stem bronci)
(2nd Phase)
221. metachronal wave The cilia “stroke” at a rate of about 15 times per second, which produces a sequential motion of the cilia
222. Microscopic view of mucous membrane
223. Microscopic view of respiratory zone airways
224. The middle portion of the cavity is covered with a mucous membrane that is composed of ciliated pseudostratified epithelia and goblet cells
225. Midsagittal section through the upper airway
226. midsternal line *Located on the anterior chest
*Divides the thorax into equal halves
227. Monopodial Bud a single bud that develops off of an existing structure
(2nd Phase)
228. Most afferent fibers follow pathways from the lungs to the central nervous system in the vagus nerve
229. most common type of epithelia numerous pseudostratified, ciliated, columnar epithelia (al
230. Most divisions of airways occur in a nonsymmetric fashion called: irregular dichotomous branching
(2nd Phase)
231. Most of the active water absorption is facilitated by active sodium channel activity that is stimulated by: *fetal and maternal thyroid hormones
*glucocorticoids
*epinephrine
*increasing fetal lunf
*blood O2 content.
232. mucociliary escalator stroking action of millions of cilia propels the surrounding mucus at a speed of about 2 cm/min.
233. Mucosal fluids remove water-soluble irritant gases such as sulfur dioxide
234. The mucosal surfaces of the oral cavity -also provide humidification and warming of inspired air
-these surfaces are much less efficient than the nose
235. Mucus functions to protect the underlying tissue. It helps to prevent excessive amounts of water from moving into and out of the epithelia
236. Mucus functions to protect protect the underlying tissue. It helps to prevent excessive amounts of water from moving into and out of the epithelia.92 It shields the epithelia from direct contact with potentially toxic materials and microorganisms. It acts like sticky flypaper to trap particles that make contact with it. This makes mucus an important part of the pulmonary defenses.
237. The mucus normally produced is a mixture of 97% water and 3% solute
238. Mucus production increases when the respiratory tract is irritated by particles and by various chemicals and during increased parasympathetic nervous stimulation
239. Muscle fibers crisscross and spiral around the airway walls. This placement reduces the diameter of the airway and shortens it when the muscle contracts. This pattern of smooth muscle continues but thins out on reaching the smallest bronchioles. The tone of the smooth muscle is increased and results in bronchospasm by the activity of the parasympathetic nervous system (release of acetylcholine) and proinflammatory mediator release from mast cells, inflammatory cells, and neuroendocrine cells.
240. These muscles are primarily responsible for enlarging the thorax during inspiration and allow exhalation by relaxing and allowing the thorax and lungs to recoil back to their preinspiratory position. The Diaphragm & intercostal muscles
241. Mutations of the FGF10 Gene can result in: tracheal development but fetal failure of further lung formation
(1st Phase)
242. The nasal cavity functions are to.. conduct air to and from the respiratory tract, to condition inhaled gas, to act as a region to which sinus and eye fluid drain, and to contain olfactory sensors for the sensation of smell
243. Nasopharynx lies at the posterior end of the nasal cavity and extends to the tip of the uvula
244. The nervous system of the repiratory tract forms from the cells of the ectoderm that grow within the mesoderm layer
245. neuroendocrine cells (also known as Kulchitsky cells) that are often organized into small clusters called neuroepithelial bodies
246. nexin outer pairs of microtubules are interlinked by a filamentous protein
247. NKX2-1 Gene
AKA: thyroid-specific transcription factor (TTF1)
*is the initial step in the development of the respiratory system
*stimulates primary lung bud formation
*Failure or mutation of this gene can lead to failure of lung bur formation and various tracheoesophageal malformations
(1st Phase)
248. noncholinergic (NANC) system nerve fibers travel within the vagus nerve to each lung. When active, the NANC nerve endings release a neurotransmitter that promotes the production of nitric oxide, which causes the relaxation of airway smooth muscle and dilation. The NANC system is also thought to be capable of causing bronchoconstriction through the local reflex release of substance P and neurokinin A
249. Nonrespiratory function of the pulmonary circulation *The pulmonary circulation also acts as a filter for the systemic circulation.
*The capillaries have an inner diameter of about 7 to 10 µm and theoretically trap particles (e.g., blood clots) down to this size before they enter the systemic circulation, where blockages could be life-threatening.
250. number of alveoli in adult lungs range from 270 to 790 million, with an average of about 480 million.32 The number of alveoli increases with the height of the subject. Alveolar size varies with lung volume and averages about 0.2 mm in diameter when the lung is inflated to its functional residual volume. Figure 8-53 shows alveoli in a normal rat lung at different states of inflation and how their shapes change. When inflated at and beyond the functional residual volume (see Figure 8-53A-C), alveoli have a polyhedral shape that results from numerous flat walls rather than a curved spherical structure
251. Obliques Fissures *In both lungs
* begins on the anterior chest at approximately the sixth rib at the midclavicular line.
*These fissures extend laterally and upward until they cross the fifth rib on the lateral chest in the midaxillary line.
* The fissures continue to the posterior chest to approximately the third thoracic vertebra.
252. # of alveoli in a full-term newborn infant 50million
*This # continues to increase for 2-3 years after birth.
*these alveoli are lined with Type I and II pneumocytes covering the capillaries that have formed just below the basement membrane
253. ______% of blood flow entering the pulmonary artery takes the path of least resistance by shunting through the ductus arteriosus and flows to the aorta. 90%
254. _____% of blood flows to the lungs 10%
255. # of genes required for normal respiratory development 40
(1st Phase)
256. Oropharynx is located in the posterior region of the oral cavity that spans the space between the uvula and the upper rim of the epiglottis
257. The outer covering of the thorax is formed by the integumentary system, which includes: skin, hair, subcutaneous fat, and breast tissues
258. The palatine tonsils -sit between these folds on each side
-the palatine tonsils are vascularized lymphoidal tissues that play an immunologic role, especially in childhood
259. Parasympathetic fibers form their ganglia much closer to the target tissues (e.g., bronchioles, glands, and blood vessels) and have much shorter postganglionic nerve fibers
260. The parasympathetic nervous preganglionic fibers exit the brainstem via the two vagus nerves. On entry into the chest, the vagus nerve branches to the larynx. This branch is called the recurrent laryngeal nerve.
261. The parasympathetic postganglionic fibers generally secrete acetylcholine as their primary neurotransmitter when they receive signals from the brainstem
262. Parts of a rib
263. Patients with advanced chronic obstructive pulmonary disease (COPD) often use accessory muscles to assist the flattened diaphragm and to help relieve their work of breathing. The muscle groups used include shoulder and neck muscles normally used to move the arms and head. To use these muscles, the shoulder girdle must be stabilized. Patients with COPD often do this by supporting their arms on a stationary object in front of them to form the “tripod” position to immobilize the shoulders so that the accessory muscles can raise the anterior chest wall.
264. Patietal Pleura thin membrane covering the surface of the chest wall, mediastinum, and diaphragm that is continuous with the visceral pleura around the lung hilum.
*Lines inner layer of thoracic Wall
265. The pectoral girdles is formed by: *The clavicle and the scapula
*Pectoral girdles are housed in the upper and lateral regions of the thorax.
266. The Pectoralis Major Originates: on the humerus
Inserts: onto the clavicle and sternum.
267. The pectoralis major and minior can lift and enlarge the thorax when the arms are braced by leaning forward on the elbows (trippoding)
268. The pectoralis Minor Originates: from the anterior region of the ribe 3-5
Inserts: onto the scapula.
269. Period After Birth Birth:
First breath and lung fluid cleared, adult circulatory pattern established8-10 yr:
470 million mature alveoli formed
270. Permant closure of the tissue flap covering the formen ovale may take several months
271. Pharynx the posterior portion of the nasal and oral cavities opens into a region
-the entire pharynx is lined with stratified squamous epithelium
272. The pharynx is subdivided into… the nasopharynx, oropharynx, and hypopharynx, or laryngopharynx
273. Phrenic Nerves Paired nerves that originate as branches of spinal nerves C3-5, pass down along the mediastinum, and innervate the diaphragm
274. The Placenta *provides effective circulatory interface with circulation of the monther.
275. The Placenta Through Gestation *villi increase in # & complexity
*erode the endometrium
*Create irregular pcokets called intervillous
spaces in the placenta which fill with
maternal blood.
276. Pleural Fluid *is spread over the surface of both lungs
*Functions as a lubricant to reduce friction as the lungs move within the thorax & as an airtight seal that adheres to 2 pleural membranes.
*Secreted and reabsorbed.
277. Pleural membranes serous membranes that cover the surfaces of:
1. the inner thoracic wall (parietal pleural membrane)
2. mediastinum (parietal pleural membrane)
3. Lungs (visceral pleura)
278. Pleurisy *pain that comes from the pleural surface;
*usually a direct result of viral infections but has been generalized to any condition
*causing pleural pain.
279. pores of Kohn found in the interstitial space are bands of elastin fibers and a collagen fiber matrix.58 These fibers support the alveolar cells and the shape of the alveolus. Small openings are located in the alveolar septa. Some of the openings allow gas to move from one alveolus to another.
280. The position of the head affects patency of airway. A)With the head flexed, the airway may be kinked, making breathing or intubation difficult.
B)Normal upright relationship of the head and neck to the chest.
C)Extension of the head straightens the airway, making breathing, clearance of material, or intubation easier.
281. Posterior axillary line *Parallel to the midaxillary line
*Located on the posterlateral chest wall.
282. posterior portion known as the soft palate because of its soft tissue composition and ability to move upward to seal off the nasal cavity
-The end of the soft palate hangs down into the posterior portion of the oral cavity,part of the soft palate is called the uvula
-The walls of the oral cavity are formed by the cheeks, and the floor is dominated by the tongue
283. Posterior view of the bones of the thorax
284. Predominant accessory muscles Scalene
Sternoclediomastoid
Pectoral
Abdominal
285. Premature infants with gestational ages of less than 32 weeks are: at greater risk for developing respiratory distress.
286. Primary changes during the 3rd phase of development (canalicular stage) *the development of 2-4 more generations of resiratory broncholes from each terminal bronchiole.
*Formation of blind tubular alveolar ducts from each respiratory bronchiole
*Greater blood vessel development
287. The primary function of the lymphatic system is : to clear fluid from the interstitial and pleural spaces to help maintain the fluid balance in the lungs.
288. primary lobule A single terminal bronchiole supplies a cluster of respiratory bronchioles. Collectively, this unit is referred to as the acinus
289. Process of Alveolarization
(Alveolar Period)
*occurs through the formation of crests along the immature airway wall, which develop further into septa that lengthen into the terminal saccule lumen;
* this effectively divides up the terminal airspace and results in greater numbers of alveoli that enlarge to a mature state with time.
290. pseudostratified cells possess 200 cilia on its luminal surface.89 Under the electron microscope, the surface of the mucus membrane looks like a “shag carpet” of cilia with about 1 to 2 billion cilia per square centimeter.
291. pseudostratified epithelial cells are held together toward their surface or apical end through three types of junctions— apical tight junctions, zonal adherens junctions, and desmosome-type junctions—and they anchored in place to the basement membrane.
292. The pulmonary arteries *form as buds off the 6th pair of aortic arches
*primitive pulmonary veins emerge from the developing heart.
(1st Phase)
293. The pulmonary artery and its branches are the only arteries in the body to carry : deoxygenated blood.
*Similarly, the pulmonary veins are the only veins that carry oxygenated blood back to the left side of the heart.
294. The Pulmonary Circulation
295. Pulmonary circulation circulation of blood from the pulmonary artery through the vessels in the lungs and back to the heart via the pulmonary vein, providing for the exchange of gases
296. The Pulmonary Circulation & Nervous System develop: parallel as the airways form
(1st Phase)
297. Rectus Abdominis *pair of muscular band that runs vertically on the anterior surface of the abdomen.
298. The rectus abdominis originates _______ & inserts _____. Originates: from the publis
Travels: upward over the abdominal cavity
Inserts: into the costal region of ribs 5, 6, & 7 and the xiphoid process of the sternum.
299. Reflexes of the mouth, pharynx, and larynx -help to protect the lower respiratory tract during swallowing
-these protective functions can be severely compromised during anesthesia or unconsciousness
-loss or compromise of these important reflexes can result in aspiration of bacteria-colonized saliva or food and can cause pulmonary infection and asphyxiation in severe cases
300. relative differences of the upper airway in relation to body size in an infant and an adult *The greater relative weight of the head can cause acute flexion of the cervical spine in infants with poor muscle tone.
Infant neck flexion causes acute airway obstruction. Although the head is larger, an infant’s nasal passages are proportionately smaller than those of an adult.
*the infant’s jaw is much rounder,and
*the tongue is much larger relative to the size of the oral cavity
*These anatomic differences increase the likelihood of airway obstruction when an infant becomes unconscious and loses muscle tone.
301. Respiratory Bronchioles *have more superficial capillaries
*are capable of gas exchange with blood
*become more elaborate as development continues
(2nd Phase)
302. respiratory bronchioles Branching of the terminal bronchioles gives rise to unique airways
303. Respiratory development *begins in the embryonic period or about day 22 after fertilization
*a small mass of cells (the respiratory primordium) begins to develop near the ventral region of the 4th pharyngeal arch of the primitive pharynx.
(1st Phase)
304. The respiratory diverticulum *a pouchlike bud (formed from the respiratory primordium) forms on day 26
*continues to grow and form a laryngotracheal tube
(1st Phase)
305. Respiratory Muscles that compress the thorax during the expiratory phase (1)
306. Respiratory Muscles that compress the thorax during the expiratory phase (2)
307. Respiratory Muscles that Expand the Throax during Inspiratory phase
308. The Respiratory system during embryonic and fetal periods *Is a fluid-filled structure that plays no role in gas exchange
*must decelop sufficiently to assume this role at birth
309. The respiratory system recieves a double blood supple from: 1. The left ventricle
2. The right ventricle
310. Resting Hemodynamic values in Adult Systemic and Pulmonary Vascular Systems
311. The ribcage is formed by _____ pairs of ribs 12 pairs
True ribs (Rib pairs 1-7)
Attached Directly to the sternum
False Ribs (8-12)
indirectly attached to stermum or not at all
Floating Ribs (11&12)
not attached to the stermum at all
312. Rib Movement #1: moves slightly, raising & lowering the stermun
#2-7: move simultaneously about 2 axes.(changes the anterposterior and the transverse dimensions in an upward and outward motion
#8-10: rotate in a similar pattern as 2-7 but the levation of the anteriot ends produce a small backward movement of the lower sternum.
#11-12: pulled upward and outward in a “caliper” motion
313. Right and Left Miclavicular Lines *parallel to the midsternal Line
*Drawn through midpiunts of the left and right clavicles
314. The roof is formed by.. the nasal, frontal, sphenoid, and ethmoid bones
315. Rule of Thumb: The 30:30 Rule Pulmonary hypertension (e.g., capillary pressure >30 mm Hg) and excessive tidal volume and airway pressure during positive pressure ventilation (e.g., tidal volume >6 ml/kg and airway pressures >30 cm H2O) can result in stress failure of the blood-gas membrane.
316. Saliva -is produced by major and minor salivary glands
-functions primarily as a wetting and digestive agent for food but provides some humidification of inspired gas
317. Scalenus Muscles
318. The scalenus muscles _______ upper chest when active lift.
*These muscles are slightly active during resting inhalation and become more active with a forceful inspiration (especially when ventilatory demands increase).
319. Schematic of sympathetic, parasympathetic, and NANC neural fiber connections to the airways and blood vessels of the lungs
320. Schematic of the autonomic innervation (motor and sensory) of the lung and the somatic (motor) nerve supply to the intercostal muscles and diaphragm
321. Sectional View of the Thoracic Wall
322. The septum separating the two cavities is formed by.. cartilage and the ethmoid and vomer bone
323. Several Functions of Pulmonary circulation 1. primary function of the pulmonary circulation is to deliver blood to the alveolar-capillary bed for the exchange of O2 and CO2 with alveolar gas and then to deliver it to the left heart.
2. serve as a barrier between the interstitial spaces and airspaces of the lung on one side and the blood within the capillaries on the other.
3. The third function is nonrespiratory and involves the production, processing, and clearance of a large variety of chemicals and blood clots.
324. Severe fetal asphyxia and increased risk of brain damange and respiratory distress in the immediate postnatal period can be caused by: *abnormal implantation of the placents
*Tearing of the placenta from the uterine wall
*decreased placental blood flow*this can retard intrauterine growtih also.
325. Sinuses -Within the skull bones and around the nasal cavity
-The sinuses are lined with a mucous membrane and drain into the nasal cavity through numerous ducts
-They function to reduce the weight of the skull, to strengthen the skull, and to modify the voice during phonation
326. Size of a newborn trachea Normal Newborn: 5-6com long & 4mm in diameter.
Preterm Infant: 2cm long & 2-3mm wide
327. Slow adapting stretch receptors (SARs) are concentrated in the small and medium-sized airways and are closely associated with the airway smooth muscle.
328. Smaller Left Lung and Shorter Right Lung *The organs within the mediastinum bulge into the left hemithorax, resulting in a narrower and slightly smaller left lung.
*The liver below the right lung elevates the right diaphragm and results in a slightly shorter right lung.
329. The smooth muscles in the medial wall of the pulmonary arterioles … cause constriction when tensed and dilation when relaxed
330. sol layer inner layer is much more fluid-like
331. solute portion is produced by goblet cells and bronchial glands; it is called mucin and is composed of protein and minerals.
332. Spinal cord injuries at the 3rd cirvicle vertebrae result in diaphragmatic paralysis.
* In this situation, the individual has lost all nervous control of the respiratory muscles and is unable to breathe.
333. Stable stage of the lungs when the lung has developed and now has around 480 million alveoli
334. Stermun Long, Vertical flat bone found on the anterior side that is composed of 3 bones:
1. Manubrium
2. Gladiolus (The Body)
3. Xiphohid Process
335. Sternal Angle
AKA angle of Louis
*The defused conneciton between the mubrium and the body.
*external marker of the point where the trachea divides into the left and right main stem bronchi
336. Sternoclediomastoid muscles Originates: from the manubrium & clavice
Inserts: on the mastoid process of the temporal bone
*This muscle typically flexrs and rotates the head and is active during shoulder shrugging.
337. Sternoclediomastoid muscles can funciton to : * lift the upper chest.
*They receive nerve impulses from branches of the accessory nerves (cranial nerve XI) and cervical nerves C1 and C2.
*These muscles are active during forceful inspiration and become visible as thick bands on either side of the neck during the inspiratory phase in an individual who is in respiratory distress.
*This motion increases the anteroposterior diameter of the chest.
338. Sternoclediomastoid muscles originate from the maubrium and clavicle and insert on the mastoid process of the temporal bone. They lifr the upper thorax when the trapezius stabalized the head
339. Stimulation of the irritant RARs can result in bronchoconstriction, hyperpnea, glottic closure, cough, and sneeze
340. The stimuli include physical manipulation or irritation, inhalation of noxious gases, histamine-induced bronchoconstriction, asphyxia, and microembolization of the pulmonary arteries
341. Stomata small holes within the parietal pleura that are the main route for pleural fluid to exit
342. Subdivisions of the mediastinum 1. sternum & pericardium- anterior copartment-contains: thymus gland and lymph nodes.
2. Middle Compartment- Contains: pericardium, heart, great vessels, phrenic, and upper portions of the vagus nerve, trachea, portions of the right and left main stem bronchi, and lymph nodes.
3. Posterior Compartment-contains: the thoracic aorta, esophagus, and thoracic duct, sympathetic nervous system ganglionic chains and lower portions of the vagus nerve and lymph nodes.
343. The submucosa of large airways contains bronchial glands, a capillary network, smooth muscle, some elastic tissue, and cartilage in larger airways.
344. Summary Checklist Chapter8 • Many different genes regulate the development of the respiratory system from conception through adult life. Many pulmonary diseases are caused by genetic abnormalities.

• The development of the respiratory system follows a well-defined schedule; interruptions or insults in the course of development can result in respiratory disease at birth and in adulthood.

• Fetal circulation and respiration differ markedly from circulation and respiration in the postnatal period.

• The transition from intrauterine to extrauterine life involves a nonaerated, fluid-filled lung converting to an efficient air-filled organ of gas exchange.

• Closure of the foramen ovale and ductus arteriosus are important events in the transition to extrauterine life.

• The thorax houses and protects the lungs; it is also a movable shell that makes ventilation possible.

• The diaphragm is the primary muscle of ventilation; together with the accessory muscles and thoracic structures, it provides the ability to move large volumes of gas into and out of the lungs.

• The lungs receive blood flow from the pulmonary circulation for gas exchange and the bronchial circulation to support airway and pleural tissue metabolism.

• The pulmonary circulation is capable of acting as a reservoir, removing blood clots and numerous mediators and activating important vasoactive agents.

• Motor and sensory neurons innervate the muscles of ventilation and various lung tissues. Autonomic neurons conduct motor and sensory signaling to control various tissues and sense various activities.

• The upper respiratory tract heats and humidifies inspired air. Its various structures also protect the lungs against foreign substances.

• The lower respiratory tract conducts respired gases from the upper airway to the respiratory zones of the lung. It contains many structures that help clear and defend the lung.

• The airways branch into lobes in both the right and the left lungs; these lobes consist of various segments.

• The respiratory bronchioles, alveolar ducts, and alveoli provide a large, yet extremely thin membrane for the exchange of O2 and CO2 between air and blood. Disruption of the blood-gas barrier can occur from excessive capillary pressures and lung inflation and from exposure to various toxins (e.g., 100% O2).

345. Supernumerary arteries branch at 90 degree angles from the conventional arteries and travel outside the common path.
*account for about 25% of the cross-sectional area of the pulmonary arterial system
346. Supporting structures of the tracheobronchial tree, including muscle and connective tissue develop from * The mesoderm that surrounds the developing lung bud
347. Supraclavicular and intercostal retractions are nward movements of the soft tissues above the clavicle and between the ribs of the chest wall during inspiration. This inward movement causes the clavicle and ribs to stand out prominently during inspiratory efforts.
348. Suprasternal Notch
(AKA Jugular)
notch above the sternum formed by the superior edge of the manubrium
349. Surface fluids -originate from the goblet cells and submucosal glands
-this fluid lining has mild antibacterial properties
350. The surface of the nasal cavity is covered with epithelia
351. Surfaces of the Lung *The anterior, lateral, and posterior lung surfaces lie and move against the thoracic inner wall.
*The medial surfaces of the lungs lie in close contact to the mediastinal surfaces.
352. Surfactant is primarily composed of phospholipids (dipalmitoylphosphatidylcholine) and proteins (surfactant proteins A through D). It functions to reduce the surface tension of the alveolus, sheds water from the alveolar surface, helps to prevent alveolar surface tension-driven collapse, improves lung compliance, reduces the work of breathing, and protects the alveolar surface. Normally, surfactant is removed from the alveolar space continuously by type II cells and macrophages. .
353. Surfactant Synthesis is regulated by: *Numerous hormones and factors including:
glucocorticoids androgens
prolactin thyroid hormones
insulin Catecholamines
*estrogens
354. sympathetic fibers form their ganglia along the spinal cord and then form longer postganglionic fibers that penetrate the lungs and end on the airway smooth muscle and glands
355. sympathetic postganglionic fibers in the lung release epinephrine into the circulation when they receive sympathetic signals from the spinal cord
356. the tansition between fetal and extrauterin circulations is complete when the last right-to-left shunt closes.
357. Terminal Bronchioles *similar to bronchi and the trachea
*are conducting airways only
*do not participate in gas exchange with blood
(2nd Phase)
358. Terminal bronchioles he smallest conducting airways and function to supply gas to the respiratory zone of the lung.
359. Terminal Saccular Stage 26th wk-birth:
Terminal saccules increase in number, pulmonary capillary density and proximity increase, type I and II pneumocytes continue to multiply, surfactant production increases, extrauterine life possible with support
360. Terms used to describe anatomical structures
361. there are ______ paires of intercostal muscles are found between the ribs. 11
362. The Thoracic Cavity * Formed by tissues of the chest, upper back, and diaphragm.
*cone-shaped
*Houses the lungs and the contents of the mediastimum
*Functions to protect bital organs within
*Capable fo changing shape to enable air to move in and out of the lungs
363. The thoracic cavity is formed by what 3 tissues? Epithelial
connective
muscle tissue
364. The thoracic cavity is subdivided into: 1. Mediastinum
2. left and right pleural cavities.
365. Three important bypass pathways function in the developing fetus to enhance the flow of blood to the developing organs: 1. ductus venosus
2. ductus arteriosus
3. foramen ovale.
366. Three Pairs of Scalene Muscles Scalenus anterior
Scalenus Medius
Scalenus Posterior
Arise: formt he lower 5 or 6 cervical vertebrae
Insert: the clavicle and first 2 ribs
367. Three shelflike bones protrude into the cavity from the lateral walls.These bony shelves are called.. the superior, middle, and inferior conchae
-also known as turbinates
368. Thyroid cartilage forms most of the upper portion of the larynx and is generally referred to as the Adam’s apple
-just below the thyroid cartilage is the cricoid cartilage
369. The top of the lungs, viewed posteriorly, extends upward from the eighth or ninth thoracic vertebra to the first thoracic vertebra.
370. The tracheal bud *bifurcates into 2 main stem bronchial buds
(1st Phase)
371. The transverse abdominis *lie below the internal oblique muscles.
*These muscle fibers run around the lateral wall of the abdomen
372. The transverse abdominis originate_______ & insert _______ Originate: on the lower 6 ribs, iliac crest, and inguinal ligaments
Inserts: linea alba
373. Transverse sectional view of the thorax showing its contents.
374. Trapezium innervation and insertion originate: from occipital bone, 7th cervical vertebra, & all thoracic vertebrae
Insert: onto the scapulae & lateral third of the clavicles.
375. Trapezius muscles are:
& thier action is to:
*flat muscles located on the upper back and neck

*rotate the scapulae, lift the shoulders, and flex the head up and back.
*they become active during foeceful inspiration by helping brace the head allowinf the sternoclediomastoid muscles to lift the thorax.

376. Type I cells become: the primary gas-exchange cell sin the lung with close approximation to developing pulmonary capillaries
(Phase 4)
377. Type II cells do not function as gas exchange membranes as the type I cells do. They (along with the Clara cells) manufacture surfactant, store it in vesicles called lamellated bodies
378. Type II pneumocytes: form and secrete the vital pulmonary surfactants that are necessary to later the surface tension and help keep the lungs inflated.
(Phase 4)
379. The upper respiratory tract the airways that start at the nose and mouth and extend down to the trachea
380. The uvula and the surrounding walls control the flow of air and fluid and food during eating, drinking, sneezing, coughing, and vomiting
381. The vagus afferent pathways are activated by a variety of different receptors within the lung that are sensitive to inflation, deflation, and chemical stimulation
382. Various stages in the growth of the bronchi as the lungs enter the pseudoglandular period of development
383. Venous Blood from the superior Vena Cava is directed: downward through the right atrium into the right ventricle and then into the main pulmonary artery.
384. vestibules have hairs that act as a gross filter
385. Visceral control of the smooth muscle of the respiratory system is carries out by the branches of what nervous systems? 1. Sympathetic Nervous System (blood vessels cause vasoconstriction)
2. Parasympathetic Nervous System (produces Mucoud)
3. Mediators transported to the lungs via pulmonary circulaiton.
386. Visceral Pleura * Covers the Lung
*thin membrane covered by mesothelial cells that covers the entire surface of the lung, dipping into the lobar fissure
387. Viscoelastic the ability of mucus to deform and spread when force is applied to it.
388. Viscoelastic refers to the ability of mucus to deform and spread when force is applied to it.
389. What is found lining most conducting airways? *cilia
*mucous glands
*goblet cells
(2nd Phase)
390. What makes up the bulk of the placenta? *Uterine tissues
*blood vessels of the fetal chorionic vili
391. When the umbilical cord is clamped cessation of umbilical and placental blood flow causes closure of the ducts venosus and a rapis increast in systematic vascular resistance.
392. Whipping action of the cilium within the sol layer of mucus produces a metachronal wave motion
393. Why are infants more prone to collapse and compressions in airways? Because the trachea and larger bronchi of a neonate lack the rigidity of adult central airways.
394. Xiphoid Process pointed lower portion of the sternum.