Cardiovascular control and homeostasis

Question 1

What is blood pressure?

Answer 1

how hard blood is pushing against the artery wall in systole and diastole (120/80mmHg)

Question 2

What is systemic vascular resistance/ total peripheral resistance (SVR or TPR)?

Answer 2

• total resistance to blood flow caused by all of the systemic arteries/ arterioles (not the pulmonary bed)
• if lots of arterial vasoconstriction the SVR will be high

Question 3

What is an ionotope?

Answer 3

a drug that makes the heart beat harder

Question 4

What is a chronotrope?

Answer 4

a drug that makes the heart beat faster

Question 5

What detects changes in blood pressure and where are they located?

Answer 5

baroreceptors in the internal carotid arteries and in the aortic arch

Question 6

What part of the brain do the baroreceptors sent information to about the change in blood pressure?

Answer 6

the medulla oblongata and the hypothalamus

Question 7

What is the renin angiotensin system?

Answer 7

1) BP falls in kidney
2) renin secreted into the blood from adrenal glands]
3) converts angiotensinogen into angiotensin 1
4) Enzyme called angiotensin converting enzyme in lungs converts angiotensin 1 into angiotensin 2

Question 8

What does angiotensin 2 do?

Answer 8

• stimulates sodium resorption in kidney- leads to water resorption
• vasoconstriction- increases BP
• release of aldosterone from adrenal cortex- increases Na and water resorption in kidney
• release of ADH from posterior pituitary- increases water resorption in kidney and causes thirst