Control of blood volume

Question 1

How does arterial pressure affect urine output?

Answer 1

Increased arterial pressure causes an increase in urine output.

Question 2

ADH is released by the pituitary gland in response to what?

Answer 2

• Increased osmotic pressure
• Hypovolemia
• Angiotensin II

Question 3

How does ADH increase blood volume?

Answer 3

It increases water permeability in renal collecting ducts (decreasing urine production).

Question 4

What cells produce Renin?

Answer 4

Juxtoglumerular cells

Question 5

What hormone opposes the RAAS system?

Answer 5

Atrial-natriuretic hormone

Question 6

How long many amino acids long is the atrial-natriutic hormone?

Answer 6

28

Question 7

What causes the release of the atrial-natriuretic hormone?

Answer 7

It is released in response to stretching of the atria

Question 8

What percentage of blood volume is lost in class 1 shock?

Answer 8

10-15%

Question 9

What percentage of blood volume is lost in class 2 shock?

Answer 9

15-30%

Question 10

What percentage of blood volume is lost in class 3 shock?

Answer 10

30-40%

Question 11

What percentage of blood volume is lost in class 4 shock?

Answer 11

> 40%

Question 12

What reflex responds immediately to hypovolaemia?

Answer 12

The baroreceptor reflex

Question 13

What is the response of the body later to hypovolaemia?

Answer 13

• Arteriolar constriction
• Decreased renal blood flow
• Baroreceptors plus thirst

Question 14

Name some resuscitation fluids which are given in response to severe hypovolaemia

Answer 14

• Colloid fluids (gel/starch/albumin) or Hartmann’s fluid

Question 15

What other factors affect blood pressure control?

Answer 15

• Cortex (emotions, nerves from cortex to CVC centre)
• Time of day
• Respiration