lecture 6 - arteries & veins

Question 1

Where do all major arteries originate?

Answer 1

The aortic arch

Question 2

What branch of the aorta do the arteries of the legs ultimately originate from?

Answer 2

The descending aorta

Question 3

What are the 6 major arteries of the leg, in descending order (superior to inferior)?

Answer 3

Common iliac, external iliac, femoral, popliteal, posterior tibial, plantar arch

Question 4

What is the location of the popliteal artery?

Answer 4

Runs behind (posterior) to the knee

Question 5

What arterial feature supplies the feet?

Answer 5

Plantar arch

Question 6

What major vein that directly drains into the heart do the veins of the legs ultimately lead to?

Answer 6

Inferior vena cava

Question 7

What is the order of the 7 major veins of the legs, in ascending order (inferior to superior)?

Answer 7

Plantar venous arch, posterior tibial, popliteal, great saphenous, femoral, external iliac, common iliac

Question 8

What is the key superifical vein of the legs?

Answer 8

Great saphenous

Question 9

What venous feature drains the feet?

Answer 9

Plantar venous arch

Question 10

What are the 3 layers of the wall of a blood vessel?

Answer 10

Tunica intima, Tunica media, Tunica adventitia(externa)

Question 11

What is the innermost later of a blood vessel?

Answer 11

Tunica intima

Question 12

What is the outermost layer of a blood vessel?

Answer 12

Tunica adventitia (or externa)

Question 13

How many layers make up the tunica intima?

Answer 13

3

Question 14

What are the 3 layers of the tunica intima?

Answer 14

Endothelium, sub-endothelium, internal elastic lamina

Question 15

What is the innermost layer of the tunica intima (in direct contact with the blood inside the vessel)

Answer 15

Endothelium

Question 16

What are the characteristics of the endothelium of the tunica intima?

Answer 16

Simple squamous epithelium

Question 17

What is the sub-endothelium of the tunica intima?

Answer 17

A sparse pad of loose fibrous connective tissue (FCT) that cushions the endothelium

Question 18

What is the key function of the sub-endothelium of the tunica intima?

Answer 18

Cushions the underlying endothelium

Question 19

What is the internal elastic lamina?

Answer 19

A condensed sheet of elastic tissues found at the outermost layer of the tunica intima in blood vessels

Question 20

How does the internal elastic lamina of blood vessels differ between arteries and veins?

Answer 20

It is well developed in arteries but less developed in veins

Question 21

What is the key component of the tunica media?

Answer 21

Smooth muscle

Question 22

What are the key characteristics of the smooth muscle of the tunica media?

Answer 22

Involuntary, striated

Question 23

What are the components of the tunica media?

Answer 23

Smooth muscle and connective tissue fibres

Question 24

What connective tissue fibres are found in the tunica media, and what are their functions?

Answer 24

Elastin and collagen, for elasticity and strength respectively

Question 25

What is the thickness of the tunica media proportional to?

Answer 25

Vessel diameter and blood pressure - higher pressure = smaller diameter = thicker tunica media

Question 26

What are the relative thickness of the tunica media in arteries and veins?

Answer 26

Veins have lower pressure than artieries, so have thinner layers tunica media

Question 27

What is the structure of the tunica adventitia?

Answer 27

A sheath of loose FCT with a high content of collagen and varying amounts of elastin

Question 28

What component of the tunica adventitia provides the blood supply of the smooth muscle of the tunica media?

Answer 28

The vasa vasorum

Question 29

What are the vasa vasorum?

Answer 29

Small vessels in the tunica adventitia that supply the smooth muscle of veins and arteries

Question 30

The lympathatic and nervous system components of the blood vessels are found in which layer?

Answer 30

The outermost layer - the tunica adventitia

Question 31

What type of nerves are found in the tunica adventitia?

Answer 31

Autonomic - both sympathetic and parasympathetic

Question 32

Does the difference between systolic and diastolic blood pressure in blood vessels increase or decrease with distance from the heart?

Answer 32

Decreases

Question 33

Why does the difference in diastolic and systolic blood pressure in vessels decrease as you get further from the heart?

Answer 33

Initially, in the aorta the blood is ejected with high force into elastic arteries, causing them to store energy which is released as the heart relaxes, repressurising blood near the heart and decreasing the difference between systolic and diastolic. This phenomenon means as you move away from the heart, flow is steady

Question 34

Are arteries closest to the heart more elastic or more muscular compared to their more peripheral counterparts?

Answer 34

More elastic

Question 35

Where are arterioles located in the arterial supply network?

Answer 35

At the end, as the smallest type of artery.

Question 36

How do arterioles influence blood pressure and heart activity?

Answer 36

The resistance of these vessels determine the pressure in the supply networks and the muscle tone of the arterioles determines how hard the heart has to push to pump blood to the extremities.

Question 37

What is the basic function of a capillary?

Answer 37

To exchange blood with tissues

Question 38

What are venules?

Answer 38

The starting of the cardiovascular collecting/drainage system.

Question 39

What is the other name for venules?

Answer 39

Post-capillary venules

Question 40

What structure is found within venules and ensures unidirectional blood flow?

Answer 40

monocuspid valves

Question 41

What is the name for flow of blood in one direction within a vessel?

Answer 41

Unidirectional flow

Question 42

Do veins have thick or thin walls?

Answer 42

Thin

Question 43

Why do veins have spare capacity for more blood volume?

Answer 43

So that blood can ‘pool’ in the vessel

Question 44

What is the name for veins that have spare capacity, and can take up extra blood volume?

Answer 44

Capacitance vessels

Question 45

How many layers do the walls of veins have?

Answer 45

3

Question 46

How many layers of smooth muscle does the tunica media of veins have?

Answer 46

A few layers, usually with 2 distinct

Question 47

What is the thickest layer of a vein vessel wall?

Answer 47

The tunica adventitia

Question 48

What characteristic of the tunica adventitia of veins limits the stretching of the vessel during venous pooling?

Answer 48

High collagen levels to provide strength

Question 49

For an artery and vein with the same flow/volume through them, what is their relative cross sectional area?

Answer 49

Veins have approximately double the cross sectional area

Question 50

What is the cause of varicose veins?

Answer 50

Leaky valves in veins can cause the veins to balloon outwards due to back flow.

Question 51

What outside component helps to push blood through a vein to return it to the heart?

Answer 51

Skeletal muscle contraction