Flashcards in Response Of The Whole System Deck (15):
What is the approximate value for mean arterial blood pressure?
Below which point do we really worry about MABP?
What does the body have an orthostatic response to?
What is recumbent posture?
What are the acute effects of standing up?
Central venous pressure falls
Right atrium filling decreases
Stroke volume decreases
Mean arterial blood pressure decreases
Both pressure fall acutely and can therefore cause a loss of blood to the brain and possible faint.
After a large meal which NS activity will increase?
Parasympathetic activity to the gut increases
In intense exercise, approximately how much can flow demand increase by?
TPR decreases in exercise, what effect does this have on our blood pressure?
Venous pressure increases
When the baroreceptors detect a massive drop in BP what happens?
SNS output to heart: increase HR and SV
SNS output to arterioles: increase TPR and MABP
SNS output to veins: increase CV and SV
Biological factors which act like hormones, have a brief duration and act near the site of synthesis. They may have systemic effects but are metabolised locally.
How does carotid sinus massage affect HR?
How does the body maintain perfusion to the brain if MABP falls?
Cerebral vessels relax due to myogenic autoregulation
Which types of drugs would lower blood pressure acting directly on arterioles?
Alpha 1 adrenoceptor antagonists
L type calcium channel blockers
Angiotensin receptor blockers
How do L type calcium channel blockers work to lower blood pressure?
Prevent depolarisation-induced inwards movement of calcium ions into vascular smooth muscle cells