Structure & Function of the Circulation

Question 1

Tunica intima

Answer 1

• Endothelium and basement membrane

- Contact with blood

Question 2

Tunica media

Answer 2

• Elastic lame

- Smooth muscle

Question 3

Tunica externa

Answer 3

• Collagen
• Vasa vasorum
• Nerves
• Lymphatics

Question 4

What are vasa vasorum?

Answer 4

Blood supply for vessels

Question 5

What is the Windkessel effect?

Answer 5

• Pressure of blood starts to fall after ejection
• Energy from the stretch of the elastic tissue is converted when it recoils
• Blood flow goes from being intermittent to a continuous flow

Question 6

Angiotensin II

Answer 6

Powerful vasoconstrictor

Question 7

Which blood vessels are a major control point for the circulatory system?

Answer 7

Arterioles

- lots of smooth muscle

Question 8

Which blood vessel is a major site for the formation of tissue fluid?

Answer 8

Capillaries

Question 9

Is there more blood in veins or arteries, why?

Answer 9

Veins, less muscular, more distensible so open up more to “store” blood - not static

Question 10

What structure do veins have in the intimate to make sure blood flows back to the heart?

Answer 10

Valves

Question 11

What does the lymphatic system do?

Answer 11

Deleivers excess tissue fluid generated from the capillaries to the cardiovascular system

Question 12

What is an oedema and how is it caused?

Answer 12

Build up of tissue fluid caused by impaired lymphatic flow

Question 13

Immune role of lymphatic system: Lymph nodes

Answer 13

Wucheria bancrofti tranported in mosquito bites and this worm becomes very dominant in the human lympatics –> elephantitis