Blood Vessels

Question 1

What are the three layers of the wall of blood vessels

Answer 1

Tunica interna
Tunica media
Tunica externa

Question 2

What is the tunica interna

Answer 2

Innermost layer of the blood vessel wall

endothelium, connective tissue (collagen, laminin, fibronectin, and other extracellular matrix molecules), and a basal layer of elastic tissue called internal elastic lamina

Question 3

What is the tunica media

Answer 3

Middle layer
Mostly smooth muscle with elastic and collagen fibres

Question 4

What is the tunica externa

Answer 4

Outermost layer
Mostly collagen and elastin fibres

Question 5

Which tunica can help distinguish between veins and arteries

Answer 5

Tunica media

Question 6

Which animals have a n azygous vein

Answer 6

All mammals but there’s some species variation

Question 7

What is the function of the azygous vein

Answer 7

Drains dorsal mid/caudal thorax and L1-L2 region since the caudal vena cava dips ventrally to go through the liver.

Question 8

Which animals have a right azygous only

Answer 8

Dogs, cats and horses

Question 9

What animals have a left azygous vein only

Answer 9

Pigs

Question 10

Which animals have a left and right azygous vein

Answer 10

Ox, sheep, goat

Question 11

What is angiogenesis

Answer 11

The sprouting of new capillaries from pre existing vessels

Question 12

What is vasculogenesis

Answer 12

The formation of blood vessels from endothelial progenitor cells (angioblasts from mesoderm)

Question 13

When do angiogenesis occur

Answer 13

Feral/ post natal development as metabolicdaly active tissues need to be close to capillaries for gaseous exchange
Adult- female reproduction like placental development
Pathology- wound healing, tumour development

Question 14

What causes angiogenesis

Answer 14

Hypoxia
Lack of oxygen so high amount of HIF
Endothelial cell tip secretes proteolytic enzymes
Causes capillary sprouts

Question 15

What is the portal system

Answer 15

When a few organs are connect in series and they obtain their blood second band from the venous outflow of another organ

Question 16

What is the advantage of the portal system

Answer 16

To transport a solute from one place to another without dilution in the general circulation

Question 17

Whjdn animals have a hepatic portal vein

Answer 17

All vertebrae

Question 18

Where does the hepatic portal vein go

Answer 18

From GI to liver

Question 19

Which animals have the renal portal vein

Answer 19

All vertebrae except mammals

Question 20

What does the renal portal vein do

Answer 20

From hind limbs to kidney

Question 21

What is anastomosis

Answer 21

It’s a bridge of blood vessel that forms so that it can rescue the blood supply and avoid necrosis

Question 22

What percentage of the blood volume is arteries

Answer 22

15%

Question 23

What is the percentage of blood in capillaries

Answer 23

5%

Question 24

What is the blood volume in the venules and veins

Answer 24

80%

Question 25

What are the different layers of blood vessels

Answer 25

Endothelium Tunica intima Tunica media Tunica adventitia

Question 26

What is in the tunica intima and media

Answer 26

Smooth muscle Collagen Elastin

Question 27

What is in the tunica adventitia

Answer 27

Collagen Elastin

Question 28

What is the diameter of the aorta

Answer 28

2cm

Question 29

Which blood vessels contain collagen

Answer 29

All except capillary

Question 30

Which blood vessels contain elastin

Answer 30

All except capillar and venule

Question 31

Which blood vessels contain smooth muscle

Answer 31

All except capillary and venule

Question 32

Which blood vessels contain collagen

Answer 32

All except capillary

Question 33

Why is a high level of elastin and collagen important in the aorta

Answer 33

It dampens the oscillating cardiac output when the blood is pushed out the heart

Question 34

Why do the artérioles have lots of smooth muscle

Answer 34

They can contract to increase blood pressure as diameter would increase Can maintain high blood pressure and maintain reistance to blood pressure

Question 35

Why do capillaries need a low blood pressure

Answer 35

No collagen or elastin, so very fragile High pressures cause lots of fluid out (tissue fluid)

Question 36

What are the three types of capillaries

Answer 36

Continuous Fenestrates Discontinued sinusoid

Question 37

What are continuous capillaries and where are they found

Answer 37

Continuous lining of endothelial cells except for clefts between cells Majority in body

Question 38

What are fenerstrated capillaries and where are they found

Answer 38

Cell membrane is compressed to permit greater fluid transmission (creating windows) In glomerular capillaries in kidney

Question 39

What are discontinuous sinusoid capillaries and where are they found

Answer 39

Some wider intercellular gaps permit increased exchange with surrounding tissues Liver, bone marrow, lymphoid tissue, some endocrine glands

Question 40

What does the venous return depend on

Answer 40

Pressure difference between venules and RA Smooth muscle contracts Valves Inspiration (abdominal compression) Skeletal muscle movement Gravity (upper body)

Question 41

What are the main functions of blood circulation

Answer 41

To transport gases to and from organs/ tissues To Deliver nutrients To remove waste To communicate To maintain constant temperature To maintain cardiac output pressure