L16-The role of exercise and stress in health and disease

Question 1

What is a typical response to mental stress?

Answer 1

Increased respiration which in turns causes increased heart rate by inhibiting vagus innervation.
SYmpathetic activity causes vasoconstriction in peripheral vessels and dilation in muscle.

Question 2

What reflex is suppressed during alerting or defence response that can result in a very high blood pressure?

Answer 2

The baroreceptor reflex is suppressed

Question 3

What can chronic stress lead to?

Answer 3

Repeated stress causes an alerting response that can result in essential hypertension

Question 4

What is essential hypertension?

Answer 4

When the repeated stress causes the vascular smooth muscles in the arteries to hypertrophy in order to compensate for the high peripheral resistance

Question 5

What is vasovagal syncope and how does it happen?

Answer 5

It is emotional fainting and is after an alerting response when there is increased vagal activity to the heart and decreased sympathetic activity to the vessels causing a fall in ABP and a faint

Question 6

How does TPR change during dynamic and static exercise?

Answer 6

During dynamic exercise the TPR decreases as there is a vasodilation the the muscle and the blood flow is rhythmic with contractions.
During static exercise the TPR increases because the vessels are compressed by the contracting muscle which increases the resistance, TPR tends to increase after the static contraction

Question 7

What is the exercise reflex and how does it work?

Answer 7

Increased respiration and cardiac output in response to exercise due to metabolites stimulating metaboreceptors. Causes vasoconstriction causing increased TPR including skeletal muscle (usually overcome by exercise hyperaemia [metabolites])

Question 8

What is the major cause of coronary vasodilation when cardiac work increases?

Answer 8

Adenosine