SM 108 Cardiovascular Histology Flashcards
Describe the 3 layers of muscular arteries?
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
What vessel is this and why?
Arteriole. Only endothelial layer and surrounding layer of a single smooth muscle cell is present, and the internal and external lamina are not visible.
What vessel is this and why?
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
How do arteries change as they progress along the vascular system?
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
What vessel is this and why?
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
Describe the 3 layers of the arterioles?
Tunica Intima = endothelial cells with thin layer of internal elastic lamina
Tunica Media = smooth muscle layer
Tunica Adventitia = thin layer of connective tissue
What vessel is this and why?
Vena Cava. Large lumen and thick layers of media and adventitia, but the adventita is thicker than the media.
What vessel is this and why?
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
Describe the 3 layers of venules?
Tunica Intima = endothelium only
Tunica Media = pericytes and/or one layer of muscle fibers
Tunica Adventitia = fused to surrounding tissues
What are the three basic layers of the cardiovascular system?
All arteries and veins have:
Tunica Intima = endothelium
Tunica Media = smooth mucle
Adventitia = outer layer of connective tissue
What vessel is this and why?
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
How do Venules change along the vasculature?
From the capillaries, venules become veins and then the Vena Cava.
The vessels become larger and gain more elastic, collagen, and smooth muscle fibers.
Describe the 3 layers of large veins?
Tunica Intima = thin
Tunica Media = thin
Tunica Adventita = large amount of smooth muscle
Describe the 3 layers of elastic arteries?
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
Describe the 3 layers of small and medium veins?
Tunica Intima = endothelium only
Tunica Media = layer of circular smooth muscle with collagen/elastin
Tunica Adventitia = thick layer with collagen and elastin
What vessel is this and why?
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
What vessel is this and why?
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.
