Topic 11: Cardiovascular System - Circulatory Shock Flashcards
Why does circulatory shock occur? (2)
- inadequate blood flow
- decreased oxygen and nutrients to cells
What are two types of shock?
- Hypovolemic
- vascular
What is hypovolemic shock? (2)
- decreased blood volume
- due to blood loss, severe burns, diarrhea, vomiting
What is Vascular shock? (2)
- Blood volume is normal, but vessels expand
- due to systemic vasodilation of blood vessels, causing decreased blood pressure
What are 3 examples of vascular shock?
- anaphylactic shock
- septic shock
- cardiogenic shock
What is anaphylactic shock? (2)
- allergic reactions
- due to lots of histamine released from mast cells
What is septic shock?
- due to bacterial toxins
What is cardiogenic shock? (2)
- pump failure causing decrease in cardio output
- heart cannot sustain blood flow
What are the three stages of shock?
1) compensatory
2) Progressive
3) Irreversible
What is the compensatory stage of shock?
- mechanisms can restore homeostasis by themselves
What does the compensatory stage of shock involve? ie. receptors etc. (3)
- baroreceptors
- chemoreceptors
- ischemia (lack of oxygen) of medulla
All components of the compensatory stage trigger the ____ (PSNS/SNS)
SNS
What is the body’s reaction in the compensatory stage? (2 steps, 5 parts)
1) increase HR and generalized vasoconstriction (except to heart and brain)
- increases BP
2) decreased blood flow to kidneys triggers renin release
- get angio II, aldosterone, ADH release
- causes vasoconstriction, increased Na+, water retention (maintain blood volume), increased thirst)
What is the progressive stage of shock? (2)
- mechanisms inadequate to restore homeostasis
- requires intervention
What is the body’s reaction to the progressive stage of shock? (3)
- lower cardiac output, therefore lowering bp in cardiac circulation and lower cardiac activity
- decrease blood to brain, decreasing cardiovascular control
- damage to viscera due to decreased blood flow, especially kidneys (can lead to renal failure)
