SM 108 Cardiovascular Histology

Question 1

Describe the 3 layers of muscular arteries?

Answer 1

Tunica Intima = endothelial cells with a visible internal elastic membrane

Tunica Media = smooth muscle layer without elastic or collagen

Tunica Adventitia = collagen and elastin, external elastic membrane visible

Question 2

What vessel is this and why?

Answer 2

Arteriole. Only endothelial layer and surrounding layer of a single smooth muscle cell is present, and the internal and external lamina are not visible.

Question 3

What vessel is this and why?

Answer 3

Long axis view of an arteriole. Arteriole because the vessel is very thin, with only a single layer of endothelial cells surrounded by the wavy spindle cells of smooth muscle

Question 4

How do arteries change as they progress along the vascular system?

Answer 4

Arteries transition from Elastic to Muscular to Arterioles to Capillaries

Along the way, vessels become smaller, lose elastic fibers and collagen, and gain smooth muscle

Question 5

What vessel is this and why?

Answer 5

Venule. Note the relatively large lumen and single layer of endothelial cells, as well as the thinner layer of smooth muscle around the endothelial cells and thick layer of adventitia

Question 6

Describe the 3 layers of the arterioles?

Answer 6

Tunica Intima = endothelial cells with thin layer of internal elastic lamina

Tunica Media = smooth muscle layer

Tunica Adventitia = thin layer of connective tissue

Question 7

What vessel is this and why?

Answer 7

Vena Cava. Large lumen and thick layers of media and adventitia, but the adventita is thicker than the media.

Question 8

What vessel is this and why?

Answer 8

Muscular Artery Wall

Note the relatively thick medial layer, indicating presence of smooth muscle. More smooth muscle in muscular arteries than in elastic arteries, which have thinner medial layers. Adventitia and intima also present, separated by external and intenral elastic lamina

Question 9

Describe the 3 layers of venules?

Answer 9

Tunica Intima = endothelium only

Tunica Media = pericytes and/or one layer of muscle fibers

Tunica Adventitia = fused to surrounding tissues

Question 10

What are the three basic layers of the cardiovascular system?

Answer 10

All arteries and veins have:

Tunica Intima = endothelium

Tunica Media = smooth mucle

Adventitia = outer layer of connective tissue

Question 11

What vessel is this and why?

Answer 11

Muscular artery. Note the presence of all three layers: intima with endothelial cells, medial layer with smooth muscle and collagenous fibers, and adventia with vaso vasorum.

Muscular artery due to presence of thick medial layer, which is rich in smooth muscle cells. Thinner medial layer would indicate elastic artery

Question 12

How do Venules change along the vasculature?

Answer 12

From the capillaries, venules become veins and then the Vena Cava.

The vessels become larger and gain more elastic, collagen, and smooth muscle fibers.

Question 13

Describe the 3 layers of large veins?

Answer 13

Tunica Intima = thin

Tunica Media = thin

Tunica Adventita = large amount of smooth muscle

Question 14

Describe the 3 layers of elastic arteries?

Answer 14

Tunica Intima of Elastic Arteries = endothelium w/ visible internal elastic membrane

Tunica Media of Elastic Arteries = smooth mucle cells and elastic lamellae

Tunica Adventitia = vaso vasorum

Question 15

Describe the 3 layers of small and medium veins?

Answer 15

Tunica Intima = endothelium only

Tunica Media = layer of circular smooth muscle with collagen/elastin

Tunica Adventitia = thick layer with collagen and elastin

Question 16

What vessel is this and why?

Answer 16

Aorta wall showing peripheral adventita containing the vaso vasorum, medial media containing smooth muslce, and internal intima lined with endothelial cells

Note the layers of external and internal elastic lamina separating the Adventitia from the Media and the Media from the Intima respectively

Media is very thick due to lots of smooth muscle in the Aorta, as well as lots of collagenous tissue

Question 17

What vessel is this and why?

Answer 17

Small muscular artery. Note the presence of a smaller medial layer, that still has smooth muscle cells visible, so clearly not an elastic artery. All 3 layers are visible but internal and elastic lamina are not visible because this is a smaller vessel.

Question 18

What component of the media in the aorta is less abundant in the vena cava?

Answer 18

Vena Cava has less elastic fibers than the Aorta, but the Vena Cava does have more smooth muscle and collagen

Question 19

What traits are unique to the Elastic Arteries on slides?

Answer 19

Tunica Intima = Endothelial AND Smooth Muscle Cells

Tunica Media = Alternating Layers of Smooth Muscle and Elastic Fibers

Question 20

What traits are unique to Muscular Arteries on slides?

Answer 20

Tunica Media = Mostly Smooth Muscle

Tunica Adventitia = Very Large w/ Collagen + Elastin

Question 21

What traits are unique to Small/Medium veins?

Answer 21

Media = many layers of Smooth Muscle

Adventitia = thick, scattered bundles of Smooth Muscle

Question 22

What traits are unique to Large Veins?

Answer 22

Adventitia = Large bundles of Smooth Muscle

Intima/Media = Small