Circulation 3 Flashcards
What is circulatory shock?
Profound circulatory failure causing poor perfusion of vital organs
What surrounds the basal lamina?
Elastic tissue - allows contraction and relaxation of vessel, and also allows collapse
What is normal arterial blood pressure?
120/80
What does normal blood pressure rely on?
- Enough blood in system
- Smooth muscle in vessels having a certain tone
- Heart pumping blood
What happens when there is no blood in vessel?
Collapse and blood pressure becomes low and unrecordable
What happens if muscle tone is decreased?
Vessel will dilate - enough vessels affected then pressure may fall
How does body detect blood pressure and oxygen?
2 carotid bodies and 2 carotid sinuses located on either side of neck
What is bifurcation?
Splitting of an artery into internal and external arteries
What does the carotid body do?
Consist of group of cells which sense partial pressure of oxygen
What does the carotid sinus do?
Respond to blood pressure
What happens if blood pressure decreases and how does this increase pulse rate?
- Carotid sinus senses change
- Respond by nerve signal to brain stem
- Brain stem activates increase heart rate and contraction via sympathetic nerves
- Increase heart contraction = increase pulse
How do brainstem keep person alive using sympathetic system?
- Increase vascular tone in limbs and abdomen increases blood pushed up to chest and head
- Adrenal glands secrete adrenaline - increase heart pumping
In practise, how does circulatory shock present in a patient?
- Low blood pressure AND
2. Fast pulse
3 main causes of circulatory shock?
- Hypovolaemic
- Septic
- Cardiogenic
What is Hypovolaemic shock?
Severe reduction in the amount of blood in circulation, which causes low blood pressure and high pulse
