Blood vessels

Question 1

Describe two physiological/anatomical differences between arteries and veins.

Answer 1

Vein to artery ratio is 70:30

Veins are more superficial than arteries. (Involved in thermoregulation)

Question 2

Describe three features of the endothelium of blood vessels

Answer 2

Squamous epithelial cell lining
Secrete clotting factors and other factors that aid in maintaining smooth muscle tone
Bound by junctional complexes

Question 3

Describe 3 features of elastic arteries

Give 2 examples.

Answer 3

Broad tunica media consists of mostly elastin
Functions to accommodate blood surges
Pushes blood downstream to medium arteries

Common carotid
Aorta
Brachiocephalic trunk
Large pulmonary

Question 4

Describe 4 features of muscular arteries

Give 4 examples

Answer 4

Main distributing type of artery
Tunica media consists of mainly smooth muscle
Controls blood flow by constriction because they have a nerve supply (neuromuscular bundle passed through tunica adventitia)
Pulsatile contractions aid in propelling blood

Distributing branches e.g. cerebral, coronary, axillary, brachial, radial, femoral

Question 5

Give 4 features of arterioles

Answer 5

<0.3mm
regulate blood flow to capillaries
media consists of smooth muscle
intima consists of elastin and endothelium

Question 6

Describe the two types of capillary.

Answer 6

1. Continuous
   Uninterrupted endothelium
   Found in skin, smooth muscle and lungs
2. Fenestrated
   Perforated endothelium
   Found in endocrine glands, renal glomeruli

Question 7

Describe the two types of venules.

Answer 7

1. Collecting venules
   Muscular, no elastin
   Passive collecting system
   Progressive increase in diameter
2. Postcapillary venues
   Union of several capillaries
   Some metabolite exchange

Question 8

What do medium veins do?

Answer 8

Drain vein plexuses e.g. cephalic vein

Question 9

Which type of blood vessel has a well developed tunica adventitia?

Answer 9

Large veins e.g. vena cava

Question 10

Describe the portal system.

Answer 10

Venous blood contains lots of digestive products
Requires filtration
Goes to liver
Drained by hepatic vein

Veins in spleen, stomach and intestines also drain into hepatic vein.

Question 11

What is a venue comitantes

Answer 11

A bundle consisting of two veins adjacent to a central artery covered in a vascular sheath.

They are found in close proximity to arteries so that the pulsations of the artery aid venous return

Question 12

Describe what an anastomoses is and what occurs at end arteries in sudden events.

Answer 12

Uniting of arteries which creates an uninterrupted circulation especially in limbs and joints. Occurs over a long time

In the event of an occlusion, cells will undergo necrosis and this could lead to MI or blindness

Question 13

Describe a physiological difference between veins and arteries.

Answer 13

No elastic and have valves