Short Term Control Of Blood Pressure

Question 1

The arterial baroreflex components (inputs and outputs to cardiovascular centres)

Answer 1

Carotid baroreceptor(glossopharyngeal nerve), and aortic arch baroreceptor (vagus nerve)

Parasympathetic vagus nerve also affects SA node to reduce HR
While sympathetic nerves increase HR with noradrenaline

Question 2

Other inputs to the medullary cardiovascular centres than arterial baroreflex

Answer 2

Cardiopulmonary baroreceptors
Central chemoreceptors
Chemoreceptors in muscles
Joint receptors
Higher centres

Question 3

What regulates blood pressure in the long term

Answer 3

Blood volume regulated by hormonal effects on blood vessels and kidneys by cardiopulmonary baroreceptors

Question 4

Effect of posture on blood pressure

Answer 4

Standing increases hydrostatic pressure causing pooling in the veins and venules of feet and legs. Preload will decrease so MAP will decrease and baroreceptor firing rate will decrease

Question 5

Reflex response to decreased MAP from standing up

Answer 5

Decrease in vagal tone (increased HR and CO)

Increase in sympathetic tone (increase HR, CO, contractility, venoconstriction, arteriolar constriction)

Question 5

Reflex response to decreased MAP from standing up

Answer 5

Decrease in vagal tone (increased HR and CO)

Increase in sympathetic tone (increase HR, CO, contractility, venoconstriction, arteriolar constriction)

Question 6

what is The vasalva manoeuvre

Answer 6

Forced expiration against a closed glottis

Question 7

Effect of vasalva manoeuvre on blood pressure

Answer 7

Initially increases as thoracic pressure is transmitted to aorta
Then VR , EDV, SV, CO, MAP will fall
The decreased MAP will be detected by baroreceptors which will initiate reflex increase in CO and TPR
After breath is taken the decrease in thoracic pressure is transmitted to the aorta
VR is restored so SV increases again but reflex effects take a wee while to wear off