Question

PATH 370 2019 WEEK 3 TOPICS ICH 15, 16, 18, 19, 20) CHAPTER 15: ALTERATIONS IN BLOOD FLOW - understand blood flow through the heart, to and from the lungs, and to and from the body list, in order, all heart chambers, heart valves, and key vessels (pulmonary trunk, left and right pulmonary arteries, left and right pulmonary veins, aorta, coronary arteries, coronary sinus, superior vena cava, inferior vena cava, tricuspid valve, bicuspid/mitral valve, aortic valve, pulmonary valve) which type of vessel controls DP/PR? in which type does exchange of materials occur? name the blood vessel that carries blood under the highest pressure - factors that influence PR - define edema and lymphedema - Blood vessel obstructions: -thrombus vs embolus; thrombosis/embolism in an artery or vein clinical manifestations, effects, life- threatening locations why would it be lifethreatening? - Arteriosclerosis/Atherosclerosis and Arterial Peripheral Vascular Disease/Peripheral Arterial Disease - formation of an atheroma and major locations where they typically occur - causes and risk factors including tobacco effects, complications and sequelae collateral circulation description, explain when and why it develops diagnosis, what is coronary bypass and why when would it be used? - Aneurysms: - description, typical locations, diagnosis effects of aneurysm rupture in terms of oxyen delivery and internal bleeding), explain why when it could be life-threatening clinical manifestations of rupture in different locations - Acute arterial occlusion: description, causes, locations where they usually occur, classic signs/symptoms description and etiology of chronic venous insufficiency - varicose veins: description, most common vein affected deep veinthrombosis (DVT): description, why can it be afe-threatening? CHAPTER 16: ALTERATIONS IN BLOOD PRESSURE - Cardiac output (CO) - CO vs SV including units of measurement - how is related to SV and heart rate (HR) - give equation -effects on CO when HR increases and SV stays the same, SV decreases and HR stays the same, cardiac diseases/conditions - Blood pressure (BP): - how is BP related to co, systemic vascular resistance (SVR peripheral resistance (PRI, HR and S effect on BP of systemic vasoconstriction systemi vasodilation, atherosclerosis, bradycardia and tachycardia, catecholamines, ADH and aldosterone stress response).renin, sitting up too quickly after lying down (orthostatic hypotension smoking, kidney disease, hypervolemia, hypovolemia function of each of the following in BP regulation sympathetic nervous system, parasympathetic nervous system, renin-angiotensin-aldosterone system (RAAS) - BP ranges for normal, pre-hypertension, and hypertension from textbook) - Primary hypertension: description, cause, risk factors, effects of long term prolonged hypertension, treatment

Answer 1

1Q). Blood flow through the heart:

The sequence of blood flow in the heart can be better remembered if one understands the anatomy of the heart. The deoxygenated blood from all the body cells enters into the vena cava (the great vein in the body), which releases blood into the right atrium.

The right atrium and right ventricle are separated by the tricuspid valve, so the blood enters the right ventricle through the tricuspid valve. Then the blood enters the lungs through the pulmonary artery from the right ventricle. The opening between the right ventricle and the pulmonary artery is guarded by the pulmonary valve. Then the oxygenated blood enters the left atrium through the pulmonary vein, again, the left auricle and ventricle are separated by a bicuspid valve, the opening between the left ventricle and aorta (great artery of the body) is separated by the aortic valve.

Thus, the pathway of erythrocyte from the left ventricle back to the left ventricle is given below: Left ventricle → Aortic valve (semilunar valve) → aorta (the largest artery) → systemic circulation → vena cava (the largest vein) → right atrium → tricuspid valve (separate the right auricle and ventricle) → right ventricle → pulmonary valve (semilunar valve) → pulmonary circulation (lungs) → left atrium → mitral valve (bicuspid valve) left ventricle

Coronary circulation is constituted by blood vessels of the heart wall. Left and Right coronary artery arising from the aorta immediately after leaving the left ventricle.

The deoxygenated blood from the capillaries of the myocardium is drained by the cardiac veins that run parallel to the coronary arteries. The veins together join to form an enlarged vein, the “coronary sinus.” The coronary sinus empties into the right atrium.

It is critical to understand the coronary circulation to understand the pathophysiology of cardiac diseases as it supplies the blood to all the cardiac cells. So, any abnormality in the coronary circulation impairs the functioning of cardiac muscle, which is generally observed in cardiac diseases such as myocardial infarction and cardiac ischemia.

The cardiac sinus empties into the right atrium. The pathway of circulation from the ascending aorta to the cardiac sinus is given below:

Ascending aorta --> left coronary artery --> circumflex artery --> walls of the left side of the heart --> cardiac veins --> cardiac sinus --> right atrium