cardiovascular system 5 Flashcards
what is shock
failure of CV system to deliever enough O2 and nutrients to meet cellular metabolic needs
what causes shock
decreased blood volume
poor heart function
blood vessels dilate
blocked blood flow
how many types of shock are there
4
name the 4 types of shock
hypovolumic, cardiogenic, vascular and obstructive
what causes hypovolumic shock
decreased blood flow
-inadequate fluid intake
-diabetes mellitus
-sudden hemorrhage
-excessive vomiting or diarrhoea
what causes cardiogenic shock
poor heart function
-heart attack
-heart valve problem
what causes vascular shock
inappropriate vasodilation
-anaphylactic shock
-head trauma
-septic shock
what causes obstructive shock
obstruction of blood flow
how does the body respond to shock
1 activation of renin-angiotensin-aldosterone system
2 secretion of ADH
3 activation of sympathetic ANS
4 release of local vasodilators
how much blood volume needs to be lost for it to become life threatening
> 10-20%
what are signs of shock
rapid resting heart rate
altered mental state
sweating
thirst
nausea
what pressure does blood travel from and to
high to low
what is BP
hydrostatic pressure exerted by blood on walls of vessel
what is resistance
opposition to blood flow
what changes the resistance
blood vessel radius
blood viscosity
total blood vessel length
name the ways substances enter and leave capillaries
diffusion
transcytosis
bulk flow
explain diffusion and what substances partake
down a conc gradient (O2, glucose and amino acids)
describe transcytosis
vesicles in endothelial cells for large insoluble lipids
describe bulk flow
high pressure to low
what is bulk flow used for
filtration out of capillaries and reabsorption in
what is filtration of bulk flow promoted by
blood hydrostatic pressure (heart)
interstitial fluid osmotic pressure
what is reabsorption promoted by in bulk flow
blood colloidal osmotic pressure
