Questions With Solved Solutions.
Circulatory system - Answer -Deoxygenated blood enters right atrium via superior and inferior
vena cava
-Right ventricle (tricuspid valve)
-Leaves heart (pulmonic valve), enters lungs (pulmonic artery) to be oxygenated
-Oxygenated blood enters left atrium (pulmonary vein)
-Left ventricle (mitral valve)
-Blood leaves heart through aortic valve, into aorta and to rest of body
Structure of blood vessels - Answer
arteriogenesis - Answer branching from larger vessels, e.g. arterioles
vasculogenesis - Answer growth of vessels from progenitor or stem-like cells that originate in
the bone marrow or already existing cells
angiogenesis - Answer new vessels grow as a branch from an existing vessel (e.g. capillaries)
Blood flow into capillary beds - Answer Move between junctions in endothelial cells, actively
diffuse across capillary membrane, use transporters, or through fenestrations
Endothelium roles - Answer -transportation of substances
-coagulation
-antithromobogenesis and fibrinolysis
-immune system function
-tissue growth and wound healing
-vasomotion: contraction and relaxation of vessles
-synthesis and release of vasoactive chemicals
veins - Answer -Thin walled and fibrous with a large diameter
,-Muscle pump: pushes blood back to the heart
diastole (atrial contraction) - Answer ventricles relaxed, filling with blood, atria contracting
systole (ventricular contraction) - Answer ventricles contract, blood leaves, atria relaxed and
filling with blood
Cardiac cycle - Answer 1) Ventricles relaxing
2) Ventricles starting to contract
3) Semilunar valves open (to aortic and vasculature) and ventricles eject the blood
4) Aorta, pulmonary valve close; ventricles start to fill back up
5) aorta starting to contract
Cardiac output = - Answer stroke volume x heart rate
What are the factors affecting stroke volume? - Answer preload, afterload, contractility
What are the factors affecting heart rate? - Answer CNS, autonomic nervous system, neural
system, hormones, atrial receptors
Preload - Answer pressure generated at the end of ventricular diastole
Afterload - Answer resistance to ejection after left ventricular systole
Frank Starling law - Answer volume of blood in heart at end of diastole is related to the force
of contraction during next systole
Laplace's law - Answer wall tension related to (intraventricular pressure * internal radius)/wall
thickness
Course of endothelial injury - Answer -Inflammation of endothelial cells, decreased release of
cytokines
-Release of inflammatory cytokines
,Fatty streak - Answer -made up of foam cells
-produce more oxygen radicals, continue to damage vessel wall
-increased smooth muscle in vessel wall, collagen ---> leads to plaque
complicated plaque - Answer -has already ruptured (rupture usually occurs because of the
inflammatory activation of proteinases)
-leads to thrombus formation at rupture site
-can cause vessel occlusion and clinical complications (e.g. ischemia)
Clinical manifestations of atheroslcerosis - Answer TIA/stroke
myocardial ischemia
mesenteric ischemia
loss of limb function
ischemia - Answer an inadequate blood supply to an organ or part of the body, especially the
heart muscles
Hypertension definition - Answer -systolic BP >140 and/or diastolic BP >90
SNS in hypertension - Answer -Increased catecholamine production (epinephrine,
norepinephrine)
-Increased catecholamine receptor reactivity
-Overstimulation of SNS --> increased HR and total peripheral resistance (TPR) - leads to renin
release, increased tubular Na reabsorption, reduction of renal blood flow
Renin-Angiotensin-Aldosterone system (RAAS) - Answer -Liver synthesizes Angiotensin ->
cleaved to Ang I by renin secreted from kidneys
-ACE from lungs converts Ang I -> Ang II
-Ang II affects CV system (structural changes in cell wall)
aldosterone increases sodium retention by kidney
Overactivity of RAAS - Answer -> increased Ang II
, Functions of natriuretic hormones (ANP, BNP, CNP, and urodilatin) - Answer -Induce diuresis
-Enhance renal perfusion/GFR
-systemic vasodilation
-aldosterone suppression
-SNS inhibition
malignant hypertension - Answer rapidly progressive hypertension
BP >~230/140
leads to encephalopathy, cerebral edema, death
Orthostatic hypotension definition - Answer Decrease in systolic or diastolic arterial BP upon
standing (within 3 minutes)
SBP drop >20 mmHg
DBP drop >10 mmHg
Dysregulation of response mechanisms - baroreceptors in carotid sinus and aortic arch
Symptoms of orthostatic hypotension - Answer dizziness, syncope, vision changes
Aneurysm - Answer localized dilation/outpouching of a vessel wall or cardiac chamber
True aneurysm - Answer involve all 3 layers of the arterial wall; a weakening of the vessel wall
false aneurysm - Answer extravascular hematoma that communicates with the intravascular
space
saccular aneurysm - Answer spherical
circumferential aneurysm - Answer all the way around vessel
Risk factors for aneurysm - Answer Arteriosclerosis
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sex (male)