Flashcards in hypovolmic shock Deck (10):
what is shock
Shock is a syndrome in which the circulatory system fails to sufficiently perfuse the body’s tissues and organs.
how does shock affect the cells?
-hypoperfusion which leads to ischemia and hypoxia
4 types of shock and what causes them
cardiogenic shock (caused by problems with heart function), obstructive shock (caused by an obstruction in the circulatory system), distributive shock (caused by an increase in vasodilation that is detrimental to the body), and hypovolemic shock.
what is hypovolemic shock
inadequate blood supply that causes hypoperfusion due to a lack of fluid in the vascular compartment.
etiology of H S
-caused by fluid loss to vascular compartment. The fluid could be lost by:
-wounds (fluid like plasma)
-(maybe edema, maybe should look at more?)
how does dec venous return affect CO?
dec VR->dec SV->preload. the dec SV will dec CO
how is BP affected by hypovolemic shock
the body may try to compensate t first but cant maintain this.
-BP will drop d/t dec blood volume. The dec BV would dec TPR which dec Bp (because bp=tpr/area of vessel wll
how does the body compensate with vasoconstriction and what results
-norepinephrineand epinephrine will cause
- systemic arterial and venous vasoconstriction in many nonessential organs excluding the heart and brain which increases venous return, increases stoke volume, increases cardiac output and increases mean arterial pressure. This vasoconstriction increases systemic
-It also allows the 350 millilitres of blood that is in the liver and more blood in the large veins of the abdomen to be mobilized.
how does the body compensate and affect the heart
norepinephrine inactivates the potassium (K+) channels of the heart allowing a faster drift to threshold and an increased frequency of action potentials, resulting in an increased heart rate.
--heart rate is also increased by epinephrine released from the adrenal medulla. These two hormones will increase the amount of Ca2+ available which increases myosin binding in cardiac muscle and therefore increases the force of cardiac contraction which increases stroke volume.