Vessels pt. 4

BP, shock

vasopressin

enhances water retention

causes vasoconstriction

secretion increased by unloading of aortic baroreceptors and atrial sensors

atrial natriuretic peptide

increases salt excretion via kidneys

released in response to stimulation of atrial receptors

shock

a pathophysiological disorder characterized by acute failure of the cardiovascular system to perfuse the tissues of the body adequately

symptoms of shock

cold, clammy skin; muscular weakness; rapid shallow breathing; rapid and weak pulse; low pulse pressure (sometimes mean pressure); reduced urine output; confusion

hypovolemia shock

caused by drop in blood (plasma) volume

e.g. hemorrhage, diarrhea, vomiting, injury

septic shock

caused by bacterial endotoxins

e.g. salmonella

cardiogenic shock

an acute interruption of cardiac function

e.g. myocarditis (inflammation of heart muscle) or myocardial infarction

anaphylactic shock

caused by allergic reaction

Frank-Starling mechanism

reduced LV contractile force

hypoxia; acidosis

Arterial chemoreceptor activity increases due to _____ and ______.

aldosterone

promotes Na⁺ and water retention by the kidneys

increase BV & BP

atrial natriuretic factor

generalized vasodilation

(increase urinary sodium excretion)

ADH

pathologically high concentrations, vasoconstriction

importance of arterial elasticity

expansion and recoil maintains steady flow of blood throughout cardiac cycle, smooths out pressure fluctuations and decreases stress on small arteries

medullary ischemic relfex

inadequate perfusion of brainstem

diffusion

oxygen, hormones, nutrients—move from higher concentration in blood; move into interstitial fluid and tissue cells

carbon dioxide and waster products—diffuse from higher concentration in tissue to blood

small solutes

larger solutes