Lecture 25: Hemorrhage Flashcards Preview

Undeleted > Lecture 25: Hemorrhage > Flashcards

Flashcards in Lecture 25: Hemorrhage Deck (16)
Loading flashcards...
0
Q

Arterial baroreflex to compensate for hemorrhage

A

rapid peripheral vasoconstriction via sympathetic drive triggered by low BP and unloading of baroreceptors. The most rapid compensatory mech.!

1
Q

hemorrhagic shock

A

when 30-40% of blood volume is lost, cannot save animal from failure if transfusion is given too late. Assoc. with sudden withdrawal of sympathetic drive (“decompensation”)

2
Q

Which areas are vasoconstricted first in Arterial baroreflex?

A

non-vital vascular beds (skeletal, spleen, cutaneous, hepatic)

3
Q

Chemoreflex compensatory mech. for hemorrhage

A

elicits increased vasoconstriction and hyperventilation. Stimulated by low O2 in blood due to low blood flow

4
Q

Cerebral Ischemia compensatory mech. for hemorrhage

A

activates sympathoadrenal system for vasoconstriction. Prolonged activation may result in strong vagal stimulation and bradycardia

5
Q

Reabsorption of Tissue fluids to compensate for hemorrhage

A

decreased capillary hydrostatic pressure promotes reabsorption of fluid. Cortisol increases capillary permeability to help this process

6
Q

Endogenous vasoconstrictors compensatory mech. for hemorrhage

A

Increases circulating levels of E and NE

7
Q

2 methods of renal conservation of water and salt in hemorrhage

A

1) vasopressin/ADH –> vasoconstrictor, promotes water reabsorption
2) angiotensin II –> vasoconstrictor, triggers release of more ADH

8
Q

Aldosterone stimulated by

A

Ang II

9
Q

Aldosterone fx

A

stimulates sodium reabsorption by the renal tubules

10
Q

what causes decrease in hematocrit?

A

increase in fluid volume relative to red blood cell concentration

11
Q

long term mechs. to increase blood volume: (2)

A

1) increased aldosterone release and decreased Na excretion

2) increased lvls of Ang II to stimulate thirst and salt appetite

12
Q

final compensation for hemorrhage

A

restoration of lost plasma proteins and blood cells

13
Q

where are plasma proteins and blood cells synthesized?

A

liver, bone marrow. proteins take few days, RBCs take 2-3 weeks

14
Q

quick acting method of restoring volume post hemorrhage?

A

reabsorption of interstitial fluid back into capillaries

15
Q

circulatory shock/hemorrhagic decompensation

A

progressive deterioration of CV function following extensive blood loss

Decks in Undeleted Class (134):