Question Answer
apnea absence of spontaneous breathing
apneustic center anatomically ill-defined, localized collection of neurons in the pons located at the level of the vestibular area that moderates the rhythmic activity of the medullary respiratory centers
biots respiration breathing characterized by irregular periods of apnea alternating with periods in which 4 or 5 breaths of identical depth are taken
chemoreceptors sensory nerve cell activated by changes in the chemical environment surrounding it; the chemoreceptors in the carotid artery are sensitive to PCO2 in the blood, signaling the respiratory center in the brain to increase or decrease ventilation
cheyne-stokes respiration abnormal breathing pattern with periods of progressively deeper breaths alternating with periods of shallow breathing apnea
hering-breuer inflation reflex the parasympathetic inflation reflex mediated via the lungs stretch receptors that appears to influence the duration of the expiratory pause occurring between breaths
pneumotaxic center bilateral group of neurons in the upper part of the pons that rhythmically inhibits inspiration independently of the vagi
vagovagal reflexes reflexes caused by stimulation of parasympathetic receptors in the airways that can result in laryngospasm, bronchoconstriction, hyperpnea, and bradycardia
what stimulates vagovagal reflexes? often associated with mechanical stimulation, as during procedures such as tracheobronchial aspiration, intubation, or bronchoscopy
is breathing conscious or automatic activity? automatic
can breathing patterns be consciously changed? yes; until willful breathing stops and the neural mechanisms resume
where does the rhythmic cycle of breathing originate? the brain stem, specifically the neurons in the medulla
higher brain ___ and many systematic receptors and ___ modify the output of the medulla. centers; reflexes
the structures of the brain function an an ____ manner to precisely control ventilation rate and depth in order to accommodate the ____ needs of the body. integrated; gas exchange
do separate inspiratory and expiratory centers exist? no; the neurons are anatomically intermingled and do not inhibit one another
the ___ contains several widely dispersed respiratory related neurons. medulla
which respiratory group contains mainly inspiratory neurons? dorsal
which respiratory group contains both inspiratory and expiratory neurons? ventral
what does DRG stand for? dorsal respiratory group
what does VRG stand for? ventral respiratory group
characteristics of DRG? bilateral in the medulla, send impulses to motor nerves of diaphragm and intercostals, provides main inspiratory stimulus
the medulla generates the ___ ___ ___, but the exact origin is unknown. basic breathing pattern
what modifies the medullas basic breathing pattern? sensory impulses that the lungs, airways, peripheral chemoreceptors, and joint proprioceptors have transmitted to the DRG
do drg nerves extend into vrg nerves? yes, many of them
do vrg nerves extend into drg nerves? only a few
characteristics of the vrg. bilateral in the medulla, send motor impulses through the vagus nerve to increase the diameter of the glottis, transmitting impulses to the diaphragm and intercostals, send expiratory impulses to the internal intercostals and abdominals
what are the two predominant theories of rhythm generation? pacemaker and network
what is the principle of the pacemaker hypothesis? that medullary cells have intrinsic pacemaker properties which drive other medullary neurons
what is the principle of the network hypothesis? that rhythmic breathing is the result of a particular pattern of interconnections between neurons dispersed throughout the vrg, the pre-Botzinger complex, and the Botzinger complex; inspiratory and expiratory neurons inhibit one another
does spontaneous respiration continue if the brain stem is transected above the medulla? yes, though irregular
does the pons promote rhythmic breathing? no; it modifies the output of medullary centers
what are the two respiratory centers of the pons? apneustic and pneumotaxic
what happens when the apneustic center gets severed from the pneumotaxic center and vagus nerve? drg neurons fail to switch off, causing prolonged inspiratory gasps interrupted by occasional expirations; aka apneustic breating
what do strong pneumotaxic signals do? increase the respiratory rate
what do weak pneumotaxic impulses do? prolong inspiration and increase tidal volume
tha apneustic and pneumotaxic centers seem to work together to control ___. depth of inspiration
where are the hering-breuer inflation reflex receptors located? in the smooth muscle of both the large and small airways
which nerve carries the inhibitory impulses from the hering-breuer reflex receptors to the drg? the vagus nerve
is the hering-breuer inflation reflex an important control mechanism in quiet breathing? no, this reflex in only activated at large tidal volumes (in adults)
why is the hering-breuer inflation reflex important? it regulates rate and depth during moderate to strenuous exercise
rapidly adapting irritant receptors in the epithelium of the larger conducting airways have ____ ____ nerve fibers. vagal sensory
stimulation of irritant receptors can cause… reflex bronchoconstriction, coughing, sneezing, tachypnea, and narrowing of the glottis
what can stimulate vagovagal reflexes? endotracheal intubation, airway suctioning, and bronchoscopy
airway suctioning and bronchoscopy can cause severe ____, ____, and ____. bronchoconstriction, coughing, and laryngospasm
what is the main trigger of chemoreceptors? H+ (indirectly CO2)
where are the central chemoreceptors located? bilaterally in the medulla
are the central chemoreceptors in direct contact with arterial blood? no, they are bathed in the csf separated by the blood-brain barrier
what is the blood-brain barrier? the semipermeable membrane that separates the cerebrospinal fluid (csf) and the blood
how does CO2 effect the central chemoreceptors? arterial CO2 easily diffuses across the blood-brain barrier, once inside it reacts with H2O, carbonic anahydrse follows resulting in H+ and HCO3, and the central chemoreceptors are extremely sensitive to H+
can H+ pass through the blood-brain barrier? rarely, it is almost impermeable to H+ and HCO3 so CO2 has to pass through then react with water once its inside
CO2 diffusing from te blood into the csf increases H+ almost instantly, exciting the chemoreceptors within seconds. T or F true
how much does alveolar ventilation increase in response to and increase in PaCO2? 2-3 L/min for each 1 mm Hg increase in PaCO2
how long does central chemoreceptor stimulation usually last while in respiratory acidosis? 1-2 days, long enough for the kidneys to raise levels of HCO3 in the blood and enough can pass the blood brain barrier to buff the H+
where are the periperal chemoreceptors located? aortic arch and bilaterally in the bifurcations of the common carotid arteries
the peripheral chemoreceptors increase their firing rates in response to what? increased arterial H+ regardless of origin
which nerve carries impulses from the carotid cemoreceptors to the medulla? glossopharyngeal
which nerve carries impulses from te aortic chemoreceptors to the medulla? vagus
which peripheral chemoreceptors have more influence over the respiratory center? carotid, due to an extremely high rate of blood flow, little time to deposit O2, and exposure to arterial blood 100% of the time
how does hypoxemia effect the peripheral chemoreceptors? low O2 makes them more sensitive to H+
why does decreased PaO2 cause incresae ventilation? because it makes the carotid chemoreceptors more sensitive to H+, which causes them to fire more frequently
how does increased PaO2 effect the periperal chemoreceptors? it makes them less sensitive to H+
why does increased PaO2 cause a decrease in ventilation? the carotid chemoreceptos become less sensitive to H+, which causes them to fire less often
when does hypoxemia not have an effect on the carotid chemoreceptors? in severe alkalemia, because even though the carotid chemoreceptors are more sensitive to H+ there is a lot less in blood at that time
the carotid bodies meet their O2 needs from dissolved O2. T or F true, because the flow rate is so fast; therefore it depends less on content and more on partial pressure
when will the nerve-impulse transmissions of the carotid bodies increase when pH and PaCO2 are normal? when PaO2 decreases to approximately 60 mm Hg
what accounts for the sharpest decrease in O2 content on the O2-Hb equilibrium curve? a decrease in PaO2 from 60 mm Hg to 30 mm Hg
what percentage do the peripheral chemoreceptors account for in the ventilatory response to Hpercapnia? 20-30%
which responds more rapidly to increased H+? peripheral
when peripheral chemoreceptors become insensitive to H+ levels because of high PaO2, what does ventilatory response depend on? the central chemoreceptors, which are uneffected by hypoxemia
high PaO2 renders peripheral chemoreceptors almost unresponsive to PCO2. T or F true
low PaCO2 renders peripheral chemoreceptors almost unresponsive to Hypoxemia. T or F true
what is asphyxia? coexisting arterial hypoxemia, acidemia, and high PaCO2
does a diagnosis of COPD on a patients chart automatically mean high PaCO2 or that O2 administration may be associated with hypercapnia? no, these characteristics are only displayed in severe end-stage disease; a small percentage of patients
O2 should never be withheld from acutely hypoxemic patients with COPD. T or F true, fear of hypoventilation and/or hypercapnia does not override oxygenating the tissues
what should you be prepared to do if O2 administration is accompanied by severe hypoventilation? support ventilation mechanically
which breathing pattern occurs when cardiac output is low, as in congestive heart failure, or brain injuries? chyene-stokes
why does decreased cardiac output cause chenye-stokes? because there is a delay in blood transit time between the lungs and the brain
what causes biot respiration? increased intracranial pressure
what can apneustic breathing indicate? damage to the pons
central neurologic hyperventilation is characterized by what? persistent hyperventilation driven by abnormal neural stimuli; related to mid-brain and upper pons damage associated with head trauma, severe brain hypoxia, or lack of blood flow to the brain
what are characteristics of central neurogenic hypoventilation? unresponsive to ventilatory stimuli; associated with head trauma, brain hypoxia, and narcotic suppression of the respiratory center
CO2 plays an important role in cerebral blood flow. T or F true
how does high CO2 effect cerebral blood flow? dilates the cerebral vessels increasing blood flow
how does low CO2 efect cerebral blood flow? constricts cerebral vessels decreasing blood flow
why is high intracranial pressure (icp) bad? if it exceeds cerebral arterial pressure, blood flow to the brain will stop, leading to cerebral hypoxia (ischemia)
why does decreasing PaCO2 help relieve icp? for every 1 mm Hg reduction in PaCO2–> 3% reduction in cerebral blood flow and for every 0.5-0.7 drop in cerebral blood flow–> 1 mm Hg reduction in icp
why is mechanical hyperventilation a cause for concern for patients with traumatic brain injuries? because with the drop in icp also comes a drop in cerebral blood flow, which can end up causing ischemia as well
what is the normal icp? 10
how long does it take for the brain to reach max swelling? 3 days
what is the most common cause of hypoxemia? hyperventilation
strenuous exercise can increase O2 consumption and CO2 production by how much? 20 fold
When reviewing a patients record what would you first look at? patient history and physical exam, RC orders, Progress notes, intake and output.
The reason why a patient came to the hospital and usually one sentence, found in admission data of the chart? Chief Complaint(CC) and history of present illness(HPI)
This describe all the patients past medical illness, injuries, surgeries, hospitalization, allergies, amd health-related habits. Which explain the basic understanding of patients previous experiences with illness and healthcare. PMH or past medical history
This par tof the medical history focuses on potential genetic or occupational links to disease and patients current life situation. Social/ Occupational and Environmental History
Physical examination consists of the FF. Inspection, palpation, percussion, auscultation.
What must you obtain in interviewing a patient 1. Determine level of consciousness, 2. check orientation to time, place and person, 3. Evaluate tolerance for ADL(activities of daily living) and nutritional status 4. Measure subjectve symptoms
Lethargic, somnolence and sleepy means. COPD 02 overdose.
Stuporous or confused. Responds inappropriately, drug overdose, intoxication
Semicomatose- responds only to stimuli but not alert.
Coma does not respond to painful stimuli.
A patient is on a drowsy state, may have decreased cough or gag OBTUNDED
Difficulty breathing especially in an upright position ussually due to CHF or heart problem ORTHOPNEA
In a physical exam ____ is an objective information, which are those things you can see ot measure. (color, pulse, edema, BP) SIGNS
In physical exam these are the subjective information, ythose things that the patient must tell you such as (Dyspnea, pain, nausea) SYMPTOM
What do you check for vital signs PULSE, RR, BP and TEMP
Open ended question when asking a patients are. Yes or NO question.
Feeling of shortness of breath or difficulty breathing DYSPNEA
Run down feeling, nausea, weakness, fatigue, headache, electrolyte imbalance GENERAL MALAISE
What are the levels of dyspnea? Grade 1-5. G1. normal dyspnea occurs after unusual exertion, G2. breathless after going up the stairs G3. SOB while walking at normal speed. G4. SOB walking at short distances. G5. Dyspnea at rest, shaving, dressing.
Difficulty swallowing Dysphagia
shortness of breath in upright position PLATYPNEA
Mucus from the tracheobronchial treen that has not been contaminated by oral secreation. PHLEGM
Mucus that comes from the lung but passes through the mouth and is expectorated SPUTUM
Sputum that contains pus cell are termed ___ which suggest a bacterial infection. it is thick colored and sticky PURULENT
Sputum that is foul smelling is called FETID
Sputum that is clear and thick commonly seen in patients with airway disease is MUCOID
Coughing up blood streaked sputum from lungs is reffered to as____ often seen in patient with cardiopulmonar disease HEMOPTYSIS
Chest pain is categorized as ____and ___ pleuritic and nonpleuritic
this type of chest pain is located laterally and posteriorly when patients take deep breath describe as sharp stabbing pain. the cause is tha pleural lining of the lung is inflamed. usually seen on pneumonia and pulmonary embolism. PLEURITIC CHEST PAIN
this type of chest pain is located anteriorly at the center of the chest and may radiate to shoulder and back It is not affected by breathing and describe as dull ache or pressure type of pain. Seen on angina and stressed a reslut from coronary disease NON PLEURITIC CHEST PAIN
a term for patients with fever febrile
no fever afebrile
fever that occurs with cough suggest a ______ respiratory infection
Patients with fever will have these signs increase Metaboloc rate, inc O2 consupmtion, inc C02 production
The normal range of temp is 98.6 F and 37 C
if the patients has a fever of 101 F then it is Low grade fever
what part of the nervous system controls the body temp. hypothalamus
when the body temp lower than normal usually seen in older people and bums during winter HYPOTHERMIA
Another term for extremely high body temperature, above 105 F HYPERTHERMIA
A body temp of 95 degrees farenheit indicates HYPOTHERMIA
Swelling of the lower extermities is ___ most commonly seen with heart failure, w/c causes an increase int he hydrostatic pressure of the blood vessels in lower extremities. Fluid leaking out of interstitial spaces. Pedal edema
Excessive fluid in tissue Pitting edema
swelling of the ankles and arms due to excessive fluid in tissue peripheral edema
Severe sweating is called____ w/c indicate fever, pain, distress, anxiety, increased metabolism. DIAPHORESIS
Evaluating the patients alertness, if the patients is conscious, and assessing the patients orientation to time, place, and person is called Evaluating the sensorium
The alert patient who is well oriented to his time, place and person is called oriented x3
The most accurate way to measure body temperature is rectal
Whas is the normal adult pulse rate? 60-100 beats/min
A condition where pulse rate exceed 100 beats/min is termed tachycardia
common causes of tachycardia are exercise, fear, anxiety, low BP, anemia, fever, reduced arterial 02 and certain medication
A condition where pulse rate is less than 60 beat/min. bradycardia
amount of blood circulated per minute is ____ is a function of heart rate and stroke volume cardiac ouput
What are the sites to obtain pulse. radial, brachial, carotid and femoral arteries.
A significant decrease in pulse strength during spontaneous inhalation, usually common with COPDers mostly people with asthma attacks. PULSUS PARADOXUS( paradoxical pulse)
Alternating succession of strong and weak pulses pulsus alternans
Normal adult breathing rate or RR is 12-20 breaths/min
Abnormally high respiratory rate is called Tachypnea
Abnormally low respiratory rate is termed Bradypnea
the peak force exerted in major arteries during contraction of the left ventricle, the higher number of BP systolic
The force in major arteries remaining after relaxation of the ventricles, lower number of B diastolic
The difference between systolic and diastolic is ____ Pulse pressure
Blood pressure less than 95/60 Hypotension
Blood pressure greater than 140/90 hypertension
A rapid drop in arterial blood pressure caused by postural hypotension can reduce cerebral blood flow and lead to ____ or fainting syncope
When obtaining BP vibration and tubulence can be heard at the stethoscope over brachial artery this sounds are called Korotkoff sounds
an abnormal bluish discoloration of the skin or mucuos membranes Cyanosis
Increased venous distention, occurs with CHF and patients with COPD seen during expiration because of the obstructive component Jugular Venous Distention
What must you do to check for pheriperal circulation Capillary refill
A state of profuse/heavy sweating, which can indicate: heart failure, Fever, infection, anxiety and nervouseness Diaphoresis
Redness of the skin. Maybe due to capillary congestion, inflammation, or infection Erythema
If a patients is hypoxic what color skin should that patient have Cyanotic
During chest configuration a patient spine leaning forward is termed also called hunchback Kyphosis
Patient chest leaning side to side lateral curvature scoliosis
this is the term when the anterior chest is protruding or protrusion of the sternum pectus carinatum
The depression of part or all of the sternum or sunken chest pectus excavatum
when a person is hunchback and leans side to side kyphoscoliosis
Intermitent sinking inward of the skin overlying the chest wall during inspiration seen in ribs, clavicles, or below rib cage Retractions
Retraction can be seen at the following parts of the body intercostal, supraclavicular, or subcostal
an abnormal breathing pattern seen as a sinking inward motion of the abdomen with each inspiratory effect; sign of diapraghm fatigue abdominal paradox
Alternating between use of the diaphragm for short periods and use of the accessory muscles to breathe. It is an indicative end stage of respiratory muscle fatigue. Respiratory Alternans
Both sides of the chest move both at the same time symmetry
Unequal movement of the chest assymetry
The following pathology can be a sign of assymetry: Chronic lung disease, Atelectasis, Pneumothorax, Flail chest-paradoxical, Intubated patient with endotracheal tube in one lung.
The art of touching the chest wall to evaluate underlying structure and function palpation
____ refers to the vibrations created by the vocal cords during speech. voice vibration on the chest wall vocal fremitus
This is the vibration that are felt by the hand on the chest wall. ask to say 99 Tactile fremitus
The normal RR, depth and rhythm Eupnea
The increase in RR over 20 Breath/min. causes; fever, pain, CNS problem tachypnea
decrease in RR rate less than 8 bpm. Cause: sleep, drugs, alcoholl, metabolic disorders bradypnea
Absence of brathing apnea
deep breathing ar normal rate hyperpnea
breaths that gradually become faster and deeper than normal, then slower for abt 30-170 sec; alternates with 20-60 sec periods of apnea Cheyne stokes
Rapid, deep breatiing with abrupt pauses (apnea) between eacfh breaTh equal depth to each other cause; CNS problem BIOTS
Rapid deep labored breathing without pauses; usually over 20bpm, increased depth, causes; renal failure, metabolic acidosis, diabetic ketoacidosis Kussmauls breathing
What are the normal breath sound vesicular, bronchovesicula, tracheal
Abnormal breath sounds is also termed adventitious breath sounds. ALS
this is the increase in muscle size hypertrophy
hypertropy is seen usually in copd patient
Tachycardia could indicate the following hypoxemia, anxiety, and stress
Bradycardia could indicate heart failure and an emergency code.
abnormal collapse of the distal lung parenchyma. collapse of lung, airless condition. atelectasis
a presence of air or gas in the pleural spaceof the thorax; pneumothorax
what are the ALS adventitious lung sounds wheeze, stidor, crackles, ronchi,
intermittent nonmusical brief crackling sounds that are caused by collalpse or fluid filled alveoli popping open, it is low pitched and hear during inspiration and expiration. crackles
high pitch sound caused by a narrowed airway, it is high pitch ans continuous wheezes
a low pitch snoring or rattling sound heard primarily on exhalation, means that fluid is partially blocking the airways ronchi
a loud high pitch crowing sound, usually heard w/out stethoscope during inspiration, caused by an obstruction at the upper airway which requires immediate attention. stridor.
a low pitch grating rubbing sound heard when patient in and exhale cause is pleural inflammation pleural friction rub
increased AP diameter, is a result of chronic air trapping in lungs due to COPD. Barrel CHest
this test is to determine whether the lungs are filled with air, fluid or solid materials. done by placing fingers in muiddle of two ribs and rapping the middle finger first. Percussion
what are the percussion sounds resonance, flatness, dullness, tymphany, hyperresonance.
Normal air filled lung gives a hollow sound. resonance
areas over the sternum, muscle or areas of atelectasis give a full sound flatness
areas over fluid filled organs such as heart or liver, Pnemonia and pleural effusion will give this sounds dullness
areas over air filled stomach. this is a drum like sound. tymphany
found in areas of the lung where pneumothorax or emphysema are present. this is a booming sound. found in a hyperinflated lung hyperresonance
normal breath sounds is also called vesicular breath sounds
when the patients is instructed to say “E” and it sounds like “A” this would indicate consolodation of the lung tissue as with a pneumonia like condition EGOPHONY
ask the patient to say 99 or blue moon. over the normal lung tissue the word will sound muffled over conslolidated ares words loud indication can be pnemonia BRONCHOPHONY
instruct patient to say 123 over normal lung tissue this will sound undistiguished but over consolidated lung tissue it will sound loud and clear. Whispered pectoriloquy
the painless enlargement of the terminal phalanghes of the fingers and toes which develops overtime, this may indicate a cardiopulmonary disease clubbing
cyannosis of the digits is also called usually indicating poor blood flow pheripheral cyanosis
pressing briefly and firmly onthe patients fingernail and noting the speed at which the blood flow returns capillary refill
what is the device called to take the BP. sphygmomanometer
decrease of BP indicated poor perfusion or shock
This blood carries the hemogobin and oxygen to the tissues RBC reb blood cell
what is the normal range for RBC 4-6 is the normal range
High RBC is termed Polycythemia
Low RBC is termed anemia
high RBC could mean increase with chronic tissue hypoxemia ie COPD
Low RBS could mean Blood loss, hemorrage. usually open wound MVA
This carries oxygen about 1.34 per gram hemoglobin
what is the normal values of Hb 12-16 is normal range of Hb
Normal range for Hematocrit is 40-50%
This fight off the bacterial infection in the body. WBC. white blood cell
what are the normal range for WBC 5,000-10,000 per cu mm
if you have an increased in WBC this means that you have ______ and is also termed______ bacterial infection- leuocytosis
Low counts of WBC means that you have _____. Low WBC is termed_____ Viral infection. Leukopenia
WHat indication should you check for Sputum Amount, Consistency(viscosity), Color,
when a patient is using their lips to themselves breath better this is termed pursed lips breathing
supine position means lying down
Question Answer
Dorsal respiratory groups contain mainly inspiratory neurons that are located bilaterally in the medulla.
ventral respiratory groups contain both inspiratory and expiratory neurons that are located bilaterally in the medulla in 2 different nulclei.
Where do DRG neurons send impulses to? motor neves of the diaphragm and external intercostal muscles providing main inspiratory stimulus
Where do VRG send impulses to? Some send motor impulses through the vagus nerve to laryngeal and pharyngeal muscles increasing the diameter of the glottis/others to diaphragm and external intercostal muscles/other internal intercostal and abd ex muscles
What are the 2 predominate thories of rythum generation? pacemaker hypothesis, network hypothesis
Pacemaker hypothesis? certain medullary cells have intrinsic pacemater properties. These cells drive other medullary neurons
Network hypothesis? rythmic breathing is the result of a particular pattern of interconnections between neurons dispersed throughout the rostral VRG, pre Botzinger complex, and Botzinger complex. Inspiratory and expiratory neruons inhibit one another
Firing rate of DRG and VRG inspiratory neurons increases gradually at the end of what phase? Creating what? expiratory. Ramp signal
During quiet breathing inspiratory neurons fire with increasing frequencyfor approximately how many seconds? 2
After the 2 second firing then an abrupt switch off occurs allowing expiration to proceed for how many seconds? 3
The inhibitory neurons that switch off the inspiratory ramp signal are comtrolled by? pneumotaxic center and pulmonary stretch receptors
The pons does not promote rythmic breathing but rather? modifies the output of the medullary centers
What are the 2 groups of neurons in the pons? apneustic center, pneumotaxic center
Apneustic Center collection of neurons in the pons located at the level of the area vestibularis that moderates the rythmic activity of medullary resp centers
Pnumotaxic center bilater group of neurons in upper pons that control swith off point of inspiratory ramp controlling inspiratory time
Strong pneumotaxic siganal increase what? RR
Weak pneumotaxic signal prolong inspiration and increase what? tidal volumes
Hering-Bruer inflation reflex parasympathetic inflation reflex mediated via lungs stretch receptors that appears to influence the durationof the expiratory pause occuring between breaths
In adults the Hering-Bruer reflex is activated only at? large tidal volumes
What reflex is important in regulating respiratory rate and depth during moderate to strenuous exercise? Hering-Breuer Inflation Reflex
What reflex is probably responsible for the hyperpnea observed with pneumothorax? deflation reflex
What reflex may help maintain large tidal volumes during exercise and may be involved in periodic deep sighs during quiet breathing Head’s Paradoxic Reflex
Rapidly adapting receptors in the epithelium of the larger conducting airways have vagal sensory nerve fibers Irritant receptors
Reflexes that have both sensory and motor vagal components? vagovagal reflexes
Reflexes that are responsible for laryngospasm, coughing, and slowing of the heartbeat vagovagal reflexes
Endotracheal intubation, airway suctioning, and bronchoscopy readily elicit what reflex? vagovagal reflexes
C fibers in the lung parenchyma near the pulmonary capillaries are called? juxtacapillary receptors, or J-receptors
Alveolar inflammatory processes (pneumonia), pulmonary vascular congestion (congestive heart failure), and pulmonary edema stimulate what receptors? J receptors
This stimulation causes rapid, shallow breathing; a sensation of dyspnea; and expiratory narrowing of the glottis? J receptor stimulation
Proprioceptors send stimulatory signals to the medullary respiratory center. increase medullary inspiratory activity and cause hyperpnea
Muscle spindles in the diaphragm and intercostal muscles are part of a reflex arc that helps the muscles adjust to an increased load
The extrafusal fibers that elevate the ribs are innervated by? alpha fibers
Those that innervate the intrafusal spindle fibers are called? gamma fibers
The body maintains the proper amounts of oxygen (O2), carbon dioxide (CO2), and hydrogen ions (H+) in the blood mainly by regulating ventilation
Hypercapnia, acidemia, and hypoxemia stimulate specialized nerve structures called Hypercapnia, acidemia, and hypoxemia stimulate specialized nerve structures called
chemoreceptors transmit impulses to the medulla, increasing ventilation
Centrally located chemoreceptors are located in the? They respond to what? medulla. Hydrogen
The stimulatory effect of chronically high CO2 on the central chemoreceptors gradually declines over 1 or 2 days, because? the kidneys retain bicarbonate ions in response to respiratory acidosis, bringing the blood pH level back toward normal
The peripheral chemoreceptors are? small, highly vascular structures known as the carotid and aortic bodies
The carotid bodies are located where? bilaterally in the bifurcations of the common carotid arteries
The carotid bodies send their impulses to the respiratory centers in the medulla via? glossopharyngeal nerve
aortic bodies send their impulses via? vagus nerve
Which peripheral chemoreceptors exert much more influence over the respiratory centers? And especially with respect to what 2 things? carotid bodies. hypoxemia and acidemia
venous blood leaving the carotid bodies has how much O2 content as the arterial blood entering them Same amount. Because the carotid bodies are exposed at all times to arterial blood
peripheral chemoreceptors fire more frequently in the presence of? Why? arterial hypoxemia. because hypoxemia makes them more sensitive to hydrogen
the ultimate effect of hypoxemia is to increase the neural firing rate of the? Which causes? peripheral chemoreceptors. Increased ventilation
why don’t conditions associated with low arterial O2 content but normal Pao2 (e.g., anemia and carbon monoxide poisoning) do not stimulate ventilation? carotid bodies’ extraction of O2 from each unit of rapidly flowing blood is so small that their O2 needs are met entirely by dissolved O2 in the plasma
When pH and Paco2 are normal (pH = 7.40 and Paco2 = 40 mm Hg), the carotid bodies’ nerve-impulse transmission rate does not increase significantly until the Pao2 decreases to about 60 mm Hg
arterial hypoxemia does not stimulate ventilation greatly until the Pao2 decreases below? 60 mm Hg
The peripheral chemoreceptors account for how much of the ventilatory response to hypercapnia? 20-30%
high Po2 renders the peripheral chemoreceptors almost unresponsive to? PCO2
low Paco2 renders the peripheral chemoreceptors almost unresponsive to? hypoxemia
Co-existing arterial hypoxemia, acidemia, and high Paco2 (i.e., asphyxia) maximally stimulate? peripheral chemoreceptors
Hypoxia-induced hyperventilation lowers the? and creates? PaCO2. alkalemia
People with chronic hypercapnia secondary to advanced COPD have depressed ventilatory responses to acute rises in? WHY? arterial CO2. because of their altered acid-base status and partly because their deranged lung mechanics prevents them from increasing their ventilation adequately
The ventilatory response to hypoxemia is greatly enhanced by? hypercapnia and acidemia
A sudden rise in arterial Pco2 causes an immediate increase in? why? ventilation. because CO2 rapidly diffuses from the blood into the CSF, increasing the [H+] surrounding the central chemoreceptors
O2 breathing causes more blood flow to be directed to? Which does what to well ventilated alveoli? poorly ventilated alveoli. takes blood flow away from well ventilated alveoli
kidneys compensate for the acidic effects of chronic hypercapnia by raising the? This does what to the pH plasma bicarbonate level. Keeps it within normal range
what are the 2 theories that describe how ventilation increases during exercising? 1.cerebral motor cortex sends impulses to exercising muscles and sends collateral excitatory impulses to the medullary respiratory center 2. exercising limbs moving around their joints stimulate proprioceptors, which transmit excitatory impulses to the me
Cheyne-Stokes respiration respiratory rate and tidal volume gradually increase and then gradually decrease to complete apnea
When does the cheyne stokes respiration pattern occur? This pattern occurs when cardiac output is low, as in congestive heart failure, delaying the blood transit time between the lungs and the brain. brain injuries in which the respiratory centers over-respond to changes in the Pco2 level
Biot’s respiration similar to Cheyne-Stokes respiration, except that tidal volumes are of identical depth
When does biots respiratory pattern occur? patients with increased intracranial pressure
Apneustic breathing indicates damage to? pons
Central neurogenic hyperventilation is characterized by? persistent hyperventilation driven by abnormal neural stimuli
neurogenic hyperventilation occurs when? midbrain and upper pons damage associated with head trauma, severe brain hypoxia, or lack of blood flow to the brain
central neurogenic hypoventilation? respiratory centers do not respond appropriately to ventilatory stimuli
central neurogenic hypoventilation occurs when? associated with head trauma and brain hypoxia, as well as narcotic suppression of the respiratory center
CO2 plays an important role in regulating? cerebral blood flow
Increased Pco2 on cerebral blood flow causes? dilates cerebral vessels, raising cerebral blood flow
Decreased PCO2 on cerebral blood flow causes? constricts cerebral vessels and reduces cerebral blood flow