Cardiovascular System

Question 1

What are the layers of the heart?

Answer 1

Pericardium/ epicardium (outer)
Myocardium (meddle)
Endocardium (inner)

Question 2

Location and function of Purkinje fibers.

Answer 2

Myocardium. Are specialized cardiac muscle cells. Part of the impulse conducting system of the heart.

Question 3

What are the layers of the blood vessels?

Answer 3

Tunica adventitia (outer)
Tunica media (middle)
Tunica intima (inner)

Question 4

Describe the Tunica Intima.

Answer 4

Has Endothelial cells, smooth muscle, elastic/ collagen fibers and mesenchymal (Stem) cells.

Question 5

Describe the Tunica Media.

Answer 5

Has smooth muscle and elastic tissue.

Question 6

Describe the Tunical Adventitia.

Answer 6

Loose network of connective tissue, elastic fibers, Vasa vasorum, and nerves.

Question 7

Effects of Norepinephrine.

Answer 7

Vasoconstriction of a and v.

Question 8

What is Vasa vasorum?

Answer 8

Penetrate tunica adventitia to connect to tunica media. Blood and nerve supply to the vessels (more in veins).

Question 9

Location and function of Endothelial cells.

Answer 9

Tunica Intima. Secretes an enzyme that cleaves Angiotensin I, which generates AT II which regulates arterial BP. Also secretes nitric oxide, von Willebrand factor and other enzymes.

Question 10

Describe an Elastic artery.

Answer 10

There are noticeable elastic fibers running through out the Tunica MEDIA. The Tunica externa does not have a distinct external elastic lamina.

Question 11

Describe a Muscular artery.

Answer 11

There is a prominent internal elastic lamina, and a thin external elastic lamina. Characterized by the thick tunica media, which has mostly circular looking smooth muscle cells.

Question 12

Describe an arteriole.

Answer 12

Have a diameter less than 0.1 mm. Thickness of their wall is approximately equal to the diameter of the lumen. Tunica intima is supported by a thin subendothelial CT layer made up of Type III collagen and elastic fibers. Tunica media in small A is a single smooth muscle layer. In larger A it is 2-3 layers. No external elastic lamina. Tunicca adventitia is barely there, it’s fibroelastic CT.

Question 13

What are the 3 kinds of capillaries?

Answer 13

Continuous, fenestrated and sinusoidal.

Question 14

Location and function of Continuous capillaries.

Answer 14

Found in muscle, nervous, connective and brain tissues. In the brain they’re modified, and have intercellular junctions between the endothelial cells called fascia occludentes. These allow passage of amino acids, glucose, nucleosides and purines across capillary walls via carried mediated transport.

Question 15

Location and function of Fenestrated capillaries.

Answer 15

Found in pancreas, intestines and endocrine glands. Have pores covered by a pore diaphragm. In the renal glomerulus, the FC do not have diaphragms.

Question 16

Location and function of Sinusoidal capillaries.

Answer 16

Found in spleen, liver and lymphoid tissue. Contain many large pores without diaphragms. Allows exchange between blood and tissues. Macrophages are present.

Question 17

Location and function of a Pericyte.

Answer 17

Outside the capillary. Form gap junctions with the endothelial cells and contain proteins that regulate blood flow.

Question 18

Describe the layers of a Vein - Vena Cava.

Answer 18

TI - endothelium, thin sunendothelial layer and a small internal elastic lamina.
TM - thin, made of smooth muscle, collagen and elastic fibers.
TA - wide, made of collagen and elastic fibers, fibroblasts and layers of longitudinally oriented bundles of smooth muscle.

Question 19

Describe a Lymph capillary.

Answer 19

Single layer of endothelium, no basal lamina, pericytes or adventitial cells. No cells found in lumen.