Regulation of Blood Pressure/Shock Flashcards
Why is blood pressure important?
Drives tissue perfusion
Supply oxygen & nutrients
Remove carbon dioxide and H+
What is important to be kept constant?
BP fluctuates Mean BP (MABP) important monitored & kept constant
What are the two main equations to take note of?
MABP = CO x TPR CO = HR x SV
What receptors monitor MABP?
Baroreceptors
What variables need to be altered to maintain MABP?
HR, SV, TPR
Name the stimulus baroreceptors respond to.
Mechanoreceptors stimulated by stretch
Where are baroreceptors found?
Carotid sinus
Aortic arch
What is the function of baroreceptors?
Constant signal to CVS centres in brainstem
What is the process that follows altering MABP?
Alter MABP –> alter signals –> reflex outputs via ANS –> SV, HR, TPR
Reflexes constantly adjust CVS function to maintain MABP
What happens if the reflexes cannot compensate for decreased MABP?
This causes persistent hypotension which can lead to shock.
What will haemorrhage cause?
Rapidly lead to a fall in MABP
Which leads to hypotension
Describe the homeostatic reflexes that occur following haemorrhage to minimize the fall in MABP.
- Immediate - baroreceptor reflex
- Intermediate - fluid shift from tissue to capillaries
- Longterm - replacement of fluid and red cells
Which hormone is responsible for retaining water?
ADH release
What system/hormones are needed for reduced renal perfusion?
RAA
What is the RAA hormones?
Renin-Angiotensin System
Group of related hormones that act together to regulate blood pressure
