Special Circulations

Question 1

Where do the right and left coronary arteries arise from?

Answer 1

• the base of the aorta

Question 2

where does the coronary venous blood drain?

Answer 2

• coronary sinus

- into the right atrium

Question 3

What is special about the coronary circulation?

Answer 3

• high density

- high basal flow

Question 4

What controls coronary blood flow?

Answer 4

• intrinsic

- extrinsic mechanisms

Question 5

Most coronary blood flow occurs in diastole

true/false?

Answer 5

• true

Question 6

What 2 arteries anastomise to form the circle of willis?

Answer 6

• carotid

- basilar

Question 7

What causes a stroke?

Answer 7

• intruption/cut off of blood flow to regions of the brain

Question 8

what controls the pressure of blood flow in the brain?

Answer 8

• autoregulation

Question 9

If MABP drops in brain what happens

Answer 9

Vessels dilate

Question 10

What is cebral perfusion pressure equal to?

Answer 10

CPP = MAP -ICP

Question 11

What protects the brain from fluctuating levels of ions in the blood?

Answer 11

• blood brain barrier

- imperamble to hydrophilic substances

Question 12

What mechanism is in place to protect the lungs from pulmonary oedema?

Answer 12

-absorptive forces>filtration forces

Question 13

Hypoxia causes vessels to ______ in lungs? and why?

Answer 13

• vessels constrict

- to divert blood away from poorly ventilated areas

Question 14

Hypoxia causes vessels to ____ in systemic circulation?

Answer 14

• vessels dilate

Question 15

What causes varicose veins?

Answer 15

-Blood pools in lower limb veins if venous valves become incompetent