Blood vessels

Question 1

3 major types of blood vessels and their function

Answer 1

Arteries: carry blood away from the heart
Capillaries: smallest blood vessels
Veins: receive blood from venules and bring it back to heart

Question 2

3 layers and what are they made of

Answer 2

Tunica intima: innermost and comprised of endothelium (simple squamous epithelium)
Tunica media: sheets of smooth muscle and elastic fibers
Tunica externa: composed of connective tissue and vasa vasorum

Question 3

Vasa vasorum

Answer 3

Blood vessels of the blood vessels
Inside the tunica externa
Bring blood to the large vessels

Question 4

3 types of arteries

Answer 4

Elastic
Muscular (distributing)
Arterioles

Question 5

Elastic arteries

Answer 5

Largest arteries
Includes the aorta and its major branches
Sometimes called conducting arteries
High elastin content dampens surge of blood pressure

Question 6

Muscular arteries

Answer 6

Also called distributing arteries
Lie distal to elastic arteries
Includes most named arteries
Tunica media is thick

Question 7

Arterioles

Answer 7

Smallest arteries

Regulate flow

Question 8

3 types of capillaries

Answer 8

Continuous
Fenestrated
Sinusoidal

Question 9

Continuous capillaries

Answer 9

Most common type
Have intercellular clefts (gaps of unjoined membranes - tight junctions)
Allow small molecules in and out (diffusion)
Skin, muscle

Question 10

Fenestrated capillaries

Answer 10

Have pores in their endothelium to allow high rates of exchange
Still tight junctions, just holes in the cells themselves
Kidney glomerulus, small intestine

Question 11

Sinusoidal capillaries

Answer 11

Wide, leaky capillaries usually fenestrated and wide open intercellular clefts
Liver, bone marrow, spleen

Question 12

Venous vessels

Answer 12

Conduct blood from capillaries towards the heart
Blood pressure is much lower than in arteries
Venules are the smallest veins (join to form veins)

Question 13

Structural differences between arteries and veins

Answer 13

In veins: lumens are larger (65% of blood in veins at any given time), tunica externa is thicker, less elastin in walls, walls are thinner than comparable arteries

Question 14

2 mechanisms to counteract low venous pressure

Answer 14

1. Valves (in limbs, prevent backflow)

2. Skeletal muscle pump (press against thin walled veins)

Question 15

How many pulmonary veins are there?

Answer 15

4

Question 16

3 branches of the aortic arch

Answer 16

Brachiocephalic trunk
Left common carotid
Left subclavian arteries

Question 17

Anastomoses

Answer 17

Neighbouring blood vessels attach together

If one of them gets blocked then the others can still supply the area

Question 18

Circle of Willis

Answer 18

Cerebral arterial circle

Anastomoses in the brain

Question 19

2 places where there are unusual patterns of venous drainage

Answer 19

1. Dural sinuses inside the skull (they do not have valves)

2. Hepatic portal system (2 capillary beds)

Question 20

3 superficial veins of the upper limb

Answer 20

Cephalic vein (back of hand next to thumb)
Basilic vein (back of hand near pinky)
Median cubital vein (used to obtain blood or administer IV fluids)

Question 21

2 superficial veins of the lower limb

Answer 21

Great saphenous vein (used in coronary artery bypass graft)

Small saphenous vein

Question 22

The hepatic portal system

Answer 22

A specialized part of the vascular circuit
Picks up digested nutrients and delivers them to the liver for processing
Two capillary beds (first in the stomach and intestines, second in liver sinusoids)

Question 23

Varicose veins

Answer 23

Dilated and tortuous superficial veins
Highly twisted and prominent under the skin
A little dilated so valves don’t meet, blood pools, dilates more, etc