Histology Of Vessels And Lymphatics - Gerdes Flashcards Preview

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Flashcards in Histology Of Vessels And Lymphatics - Gerdes Deck (10):

Arteries and veins have 3 layers which are:

Tunica intima
Tunica media
Tunica adventitia


Tunica intima

Innermost layer of endothelium, basal lamina, and subendothelial layer


Internal elastic membrane of the tunica intima

In the subendothelial layer of the intima. Sheet like layer (lamella) of fenestrated elastic material (internal elastic membrane) that lets substances diffuse And reach cells deep in the vessel wall


Tunica media

Middle layer made of circumferentially arranged layers of smooth muscle cells.

This later is pretty thick and extends from the internal to the external elastic membrane


External elastic membrane

Layer of elastin that separates the tunica media from the tunica adventitia


Tunica Adventitia

Outermost connective tissue later

Contains vasa vasorum (which supplies blood to vessel walls)


Vasa vasorum

Supplies blood to vessel walls


Basic differences between arteries and veins

1. Arteries have thicker walls and have relatively thicker TM (tunica media)

2. Veins have thinner walls, larger and more collapsed lumen, and TA is relatively more prominent


Arteries diameters

Large artery (elastic artery): > 1 cm dia
Medium artery (muscular artery): 2-10 mm
Small artery: 0.1 – 2 mm
Arteriole: 10-100 μm (histo text, but physiologists say 5-30 μm), smooth muscle layer 1 -2 cells
Capillary: 4-10 μm, only endothelium


Veins Diameters

Postcapillary venule: 10-50 μm, only endothelium and pericytes
Muscular venule: 50-100 μm, smooth muscle layer 1 - 2 cells
Small vein: 0.1 – 1 mm
Medium vein: 1–10mm
Large vein > 1cm