Lecture 4: Arteries and Veins

Question 1

Blood vessels have a 3 layered wall, what are the 3 layers called?

Answer 1

1. Tunica intima = inner layer
2. Tunica media = middle layer
3. Tunica Adventitia/Externa = outer layer

Question 2

What are the main features of the Tunica intima?

Answer 2

Endothelium: thin, flat sqaumous endothelium cells which line the lumen
Sud-endothelium: loose FCT which cushions the endothelium
Internal Elastic Lamina(IEL): elastic tissue which forms the boundary btw the intima and media
IEL = more developed in arteries
= less developed in veins

Question 3

What are the main features of the Tunica Media?

Answer 3

Smooth muscle is layered throughout the media, SM is unstriated and surrounded by CT

• elastin provides recoil, return to original diameter
• collagen provides strength and stops over expansion

Question 4

What are the main features of the Tunica Adventitia?

Answer 4

• Loose FCT with a high content of collagen and variable amounts of elastin
• In larger vessels the adventitia contains the vasa vasorum

Question 5

What is the function of arterioles?

Answer 5

Are the resistance vessels of blood circulation which determine the blood pressure by the tone of the smooth muscle in the tunica media

Question 6

What is the function of veins?

Answer 6

• low pressure & large volume transport system
• one-way directional flow
• capacitance vessels

Question 7

What is the structure of veins?

Answer 7

• Irregular flattened shape with a large lumem & THIN walls
• has spare capacity
• consists of 3 layers

Question 8

What is the function of valves in veins?

Answer 8

• Prevents back flow of blood, compensating for low blood pressure
• mostly bicuspid valves