Arteries And Veins

Question 1

What are the layers of blood vessels?

Answer 1

Tunica intima
Tunica media
Tunica adventitia

Question 2

What do the layers of blood vessels consist of?

Answer 2

Tunica intima - simple squamous epithelium, basement membrane and connective tissue
Tunica media - smooth muscle (elastic tissue)
Tunica adventitia - connective tissue

Question 3

Describe the difference in the structure of veins and arteries with regards to the layers.

Answer 3

Arteries are smaller in diameter than veins because it has a thicker wall
Arteries have a thicker tunica media
Veins have a larger tunica adventitia compared to arteries as it requires more support to attach it to its surroundings because it is floppy

Question 4

Give 3 examples of elastic arteries.

Answer 4

Aorta
Common carotid
Pulmonary

Question 5

Give examples of muscular arteries.

Answer 5

Coronary arteries
Radical artery
Femoral artery

Question 6

Arteriosus are terminal branches which supply why?

Answer 6

The blood to the capillary beds

Question 7

What is the difference between conducting and distributing arteries?

Answer 7

Conducting arteries are large elastic arteries such as the aorta.
Distributing arteries are muscular such as the coronary arteries

Question 8

How does the elastic arteries such as the aorta act as a pressure reservoir?

Answer 8

Controls the pressure so during systole the pressure doesnt go too high and diastole to ensure pressure doesn’t drop too low.
The vessel i.e. aorta stretches during systole as the heart contracts and fills with blood and recoils during diastole as the heart relaxes.

Question 9

What is the recoil and stretchability in elastic arteries due to the presence of?

Answer 9

Elastic fibres in the tunica media in the form of layers called laminae.
The fibres are secreted by smooth muscle.

Question 10

In muscular arteries, there isn’t a lot of elastic fibres like the elastic arteries. Instead the elastic fibres are concentrated where?

Answer 10

In 2 sheets called the internal elastic laminate (IEL) just under the epithelium
and the thin external/outer elastic lamina (OEL) between the tunica media and tunica adventitia.

Question 11

Histologically, what is the difference between arteries and arterioles?

Answer 11

There is no internal elastic lamina in the tunica intima
There is only 1-2 layers of smooth muscle
They only have 2 layers, they don’t have a tunica adventitia.

Question 12

What is the nerve innervation of capillaries?

Answer 12

Sympathetic

Question 13

What are pericytes and where are they found?

Answer 13

Pericytes are found in capillaries
They are an incomplete layer of cells which surround the basement membrane
They have contraction properties which help control flow of blood in the capillaries.

Question 14

Why is the blood pressure in the capillaries low?

Answer 14

Because the sum of all the capillaries in the body is less than that of the aorta

Question 15

What are the 3 types of capillaries?

Answer 15

Continuous
Fenestrated
Discontinuous

Question 16

Describe the different types of capillaries.

Answer 16

Continuous - complete basal lamina
Fenestrated - complete basal lamina with fenestrated endothelial lining
Discontinuous - incomplete basal lamina and fenestrated endothelial lining

Question 17

Where would you find a continuous capillary?

Answer 17

Muscle

Question 18

Where would you find a fenestrated capillary?

Answer 18

Endocrine glands
kidney renal Corpuscle
(Where there is secretionsyou need pores

Question 19

Where would you find a discontinuous capillary?

Answer 19

Liver, spleen, bone marrow

Question 20

Where would you find sinusoids and why?

Answer 20

Find sinusoids where large amount of exchange takes place

I.e. liver, spleen, some endocrine glands

Question 21

What cell does sinusoids contain that other capillaries don’t and where are these cells found?

Answer 21

Cinusoids contains phagocytes in their tunica intima.

Question 22

What controls the flow through the capillary beds to allow arteriovenous shunt?

Answer 22

Precapillary sphincters

Question 23

Describe arteriovenous shunts

Answer 23

Arteriovenous shunts is the diversion of blood flow from the capillary beds to the arterioles, so it bypasses the capillary beds

Question 24

Give an example of where AV shunt would occur.

Answer 24

In the skin for thermoregulation

Question 25

What prevents the backflow of blood in veins?

Answer 25

The presence of valves

Question 26

Where do the valves in the veins arise from?

Answer 26

Endothelial cells in the tunica intima which project into the lumen

Question 27

What’s the difference between superficial and deep veins?

Answer 27

Superficial veins are thicker walled and have no surrounding support
Deep veins have a thin wall but have surrounding support from deep fascia and muscles

Question 28

What does the lymphatic system drain into?

Answer 28

Venous system

Question 29

Describe the structure of lymph capillaries?

Answer 29

Lined by very thin endothelium
No fenestrations
collagenous filaments anchor endothelial cell to surround tissue keeping the lumen open

Question 30

How can you differentiate between a lymph capillary and an arterial capillary?

Answer 30

There are no red blood cells in lymph capillaries

Question 31

What’s the name for the blood supply of the blood vessels?

Answer 31

Vasa vasorum

Question 32

Where do you find the vasa vasorum?

Answer 32

In the tunica adventitia

Question 33

What type of connective tissue is the tunica adventitia?

Answer 33

Fibrous

Question 34

What type of tissue does the tunica media contain?

Answer 34

Smooth muscle tissue

Elastic tissue

Question 35

The internal thoracic artery bifurcates at which point? And what terminal branches does it divide into?

Answer 35

6th intercostal space the internal thoracic artery divides into the musculophrenic artery and the epigastric artery