Cardio A&P Lecture 3 Practice Questions:

1. ______ innervation of the heart can be either sympathetic involving which nerves? also parasympathetic involving which nerves?: Efferent – cardiac acceleratory nerves – vagus

2. As heart rate increase, _____ ______ increases – what usually determines heart rate? What is its normal value? What modifies it?: Cardiac output – the discharge of the SA node – 90-120 – ANS

3. Define Afterload – What is the effect of a high AP? What leads to an increase in after load? As after load increases, stoke volume ___________: The pressure that must be exceeded so that ejection from the ventricles can occur, it is the resistance against which the ventricles pump blood – increases ejection rate – decreases

4. Define Cardiac Output? How do we calculate Cardiac Output? What is the Cardiac Output (N Value) at rest? for athletes? What is difference between the person’s max cardiac output and cardiac output at rest? How is the affected during heart failure?: The volume of blood pumped per min by each ventricle – COP = Stroke Volume x Heart Rate – 5L/min, 20-35L/min – cardiac reserve – there will not be a drastic difference between max cardiac output and cardiac output at rest

5. Define Ischemic Heart Disease – What is the most frequent cause? Be familiar with the risk factors: A group of acute or chronic pathologies resulting from insufficient supply of oxygen to heart the heart – atherosclerotic coronary heart disease – family history of atherosclerosis, sedentary lifestyle, obesity, cholesterol rich diet, hyperlipidemia, male, smoking, alcoholism, hypertension, diabetes

6. Describe the pathogenesis of atherosclerosis (10): 1) Inflammation and damage to tunica interna 2) Accumulation and oxidation of LDLs 3) Secretions of cytokines by the endothelium (leading to platelets, macrophages, and lymphocytes) 4) Conversion of monocytes into macrophages 5) FOAM CELL creation (macrophages filled with LDLs) 6) T lymphocytes intensify inflammatory response 7) Smooth muscle cells migrate into the tunica intern causing fibrous plaques 8) Precipitation of calcium ions 9) Arterial stenosis due to narrowing of the coronary artery lumen 10) Foam cells induce clotting called thrombosis

7. Explain the role of the following factors in atherosclerosis: 1) C reactive proteins 2) Lipoprotein A 3) Fibrinogen 4) Homocysteine (AA): 1) activated during inflammation and promote uptake by LDL by macrophages 2) LDL like particle that leads to proliferation of smooth muscle fibers and prevents fibronolysis (bad) 3) vasoconstriction and platelet aggregation 4) platelet aggregation and proliferation of smooth muscle fibers (used as a marker for patients with atherosclerosis

8. The Frank-Starling Law of the Heart is called the ______ – _______ relationship – what does it maintain? How?: Tension-Length – equality of right and left cardiac output (COP) – systole is a function of diastole, so the more the heart is filled during diastole, the greater the force of contraction during systole

9. How do we calculate stroke volume? What is the value normally? What causes stroke volume to decrease? What are the three factors that affect/regulate stroke volume?: Stroke Volume = End Diastolic Volume – End Systolic Volume – 70mL – high heart rate – preload, contractility, afterload

10. How is contractility measured? How is it calculated? How does a positive/negative inotropic affect contractility and stroke volume?: Ejection Fraction – EF = SV x EDV – positive inotropic effect increases contractility and stroke volume – negative inotropic effect decreases contractility and stroke volume

11. Inotropic effects of the heart affect? Chronotropic effects on the heart affect? Dromotropic effects on the heart affect?: contractility of the heart – regulate heart rate – AV conductivity of the heart (bad when decreased, increase conductivity and lower AV lag)

12. Name 7 positive inotropic agents – Name 3 negative inotropic agents: 1) adrenaline 2) noradrenaline 3) calcium 4) cardiac glycosides 5) caffeine 6) glucagon 7) thyroid hormone – 1) acidosis 2) calcium blockers 3) hyperkalemia

13. Preload is also known as? Which is specifically? When preload (EDV) increases, stoke volume _______ – why? – What are the two factors that affect EDV?: Ventricular filling (EDV) – degree of stretch of the heart during diastole – increases – actin overlaps with myosin in A band for more forceful contractions – filling pressure (venous return increase, stroke volume increase) and filling time (duration of ventricular diastole and is inadequate when the heart rate is more than 180 bpm

14. There are ___ types of sensory receptors – name them – which two nerves do they involve? which ANS system has NO CONTROL on blood vessels?: 3 – baroreceptors – chemoreceptors – propioreceptors – vagus, glossopharyngeal – parasympathetic

15. What are propioceptors? Where are they found?: Monitor joint movement – found in the muscles, tendons, and joints

16. What are the 4 other major factors that affect heart rate?: 1) Physical training 2) Age – tachycardia in newborns 3) Gender – higher in females 4) Body temperature – fever = increased heart rate, hypothermia = decreased heart rate

17. What are the three electrolytes that control heart rate? and how?: 1) calcium – hypercalcemia = increased heart rate and contractility 2) sodium – hypernatremia = decreased calcium influx as a result so decreased heart rate and contractility 3) potassium – hyperkalemia = blocks AP generation so decreases heart rate and contractility

18. What are the three local factors that will lead to an increase in heart rate?: Hypoxia, hypercapnia, acidosis

19. What are the two hormones that control heart rate? and how?: 1) adrenaline (adrenal medulla) – positive effects on the heart 2) thyroxin – increase metabolic rate/oxygen consumption, so increase heart rate

20. What do baroreceptors do? where are they located? (2) – When ____ _____ is low, what happens parasympathetic activity? sympathetic activity?: Stretch receptors that monitor blood pressure – aortic arch and carotid sinuses of the common carotid – decreases which increases heart rate and blood pressure – increases heart rate, contractility, vasoconstriction, and venous return to return blood pressure back to normal

21. What do chemoreceptors do? Where are they located? which combination leads to an increase in heart rate, contractility, and conductivity?: Monitors blood tension of CO2, oxygen, and H+ – aortic bodies (aortic arch) and carotid bodies – high CO2 and H+ and low oxygen

22. What is the complete definition of atherosclerosis? Why is high blood cholesterol associated with atherosclerosis? What is the role of HDLs: Formation of atherosclerotic plaque in the wall of large/medium arteries, thickening and loss of elasticity of the arterial wall, hardening of arteries – LDLs carry cholesterol to receptors in the plasma membrane, they can be oxidized leading to damage to the tunica intern and conversion of monocytes into macrophages – HDLs remove cholesterol and are anti-atherosclerotic b/c arterial walls do not have receptors for HDLs

23. What type of cells of the heart is affected by parasympathetic innervation? Parasympathetic nervous system releases ______ which targets ______ – Do inotropic, chronotropic, dromotropic effects increase/decrease heart rate?: Affects both conducting atypical and contractile typical myocytes in mostly the atria – acetocholine, muscarinic receptors – decrease

24. What type of cells of the heart is affected by sympathetic innervation? Sympathetic nervous system releases ________ which targets ___________ leading to vaso…? – Do inotropic, chronotropic, and dromotropic effects increase/decrease heart rate?: Affects both conducting atypical and contractile typical myocytes in both the atria and ventricles – noradrenaline, beta 1 adrenoreceptors, vasoconstriction – increase

25. Where is the cardiomotor center located? What are its portions?: Reticular formation of the medulla oblongata – cardio-inhibitory and cardio-acceleratory portions

26. Which drug affects heart rate? How? Which division of the ANS does it affect most?: Beta Blockers – decrease heart rate by blocking beta adrenoreceptors of myocytes – sympathetic nervous system control