Regulation of MAP Flashcards
explain what happens when you stand up to MAP?
due to the decreased venous return and the lowered CO…the baroreceptors pick it up and fire less so the SNS kicks up and increases the BP back to normal
explain the role of vasopressin in the blood?
it is released when baroreceptor senses low pressures and leads to water retention as well as increasing BP of vessels
what is another name for vasopressin
antidiuretic hormone
what is bulk flow in capillaries?
when water flows following its gradient
what is the main driver that pushes fluid out in the capillaries?
hydrostatic pressure
what is the main driver that pulls fluid into the capillaries?
colloid osmotic pressure (oncotic)
AKA plasma oncotic pressure
define the plasma oncotic pressure
component of osmotic pressure contributed by macormolecules like plasma proteins…mainly albumin
if a patient has liver failure and has low albumin…what often happens in capillaries and why?
you get more filtration because of the low protein content and low plasma oncotic pressure
define capillary hydrostatic pressure
this is the pressure of the fluid within the capillary and is the biggest factor in capillary exchange
is capillary hydrostatic pressure higher at venular or arteriolar end of a cpaillary?
arteriolar
what does capillary hydrostatic pressure drive?
ultrafiltration
as you move across the capillary what happens with filtration?
it eventually loses the gradient and you start to get reabsorption
is an increase in sympathetic nervous system increasing filtration of absorption? explain
increases absorption because it causes more constriction in arteriole sphincters and therefore a decrease in the capillary hydrostatic pressure
what happens to filtration when the venous pressure really increases?
it will increase the filtration in the capillary because venous system does not have sphincter and the pressure increases in the capillaries
name three changes that lead to edema
increased venous pressure
arteriolodilation
hypoproteinemia
name two changes that lead to increase in absorption
dehydration
arteriolar constriction
how does shock happen?
a severe insult to MAP regulation systems
describe the changes of pulmonary capillary wedge pressure, CO, and SVR in hypovolemic shock?
decreased capillary wedge pressure
decreased CO
increased SVR
describe the changes of pulmonary capillary wedge pressure, CO, and SVR in cardiogenic shock?
increased pulmonary capillary wedge pressure
decreased CO
increased SVR
describe the changes of pulmonary capillary wedge pressure, CO, and SVR in distributive shock?
normal or decreased pulmonary capillary wedge pressure
increased CO
decreased SVR
name the two possible causes of hypovolemic shock
acute blood loss and profound dehydration
what is the primary insult that leads to hypovolemic shock
decrease in preload causes decrease in stroke volume
what are the compensatory mechanisms in hypovolemic shock?
tachycardia and increased SVR
what is treatment for hypovolemic shock?
either fluids or blood transfusion…depends on the cause
