Cardiac And Blood Vessel Histology Flashcards
What are metarterioles?
Blood vessels which link arterioles and capillaries
What are the 3 layers found in blood vessels?
Tunica intima
Tunica media
Tunica adventitia
Capillaries are made up of high layer only?
Tunica intima
All tunica intima are lined with which type of epithelium? What is this called in blood vessels?
Simple squamous
Endothelium
When viewing a microscope slide, how can you tell the difference between arteries and veins?
Arteries are thick walled and circular
Veins are irregular shape and thin walled
Why are veins irregular shaped in slides, and arteries are circular?
Arteries contract when cut
Veins are flaccid, pressure from surrounding structures distorts them
Why are you more likely to find RBCs in veins than arteries?
Veins are under less pressure
More likely to keep their contents when sectioned
Describe the 3 layers found in the aorta
Intima - endothelium and elastic lamina
Media - smooth muscle and elastic fibres
Adventitia - collagen and elastic fibres, vasa vasorum
Describe the layers found in arteriole walls
Normal tunica intima
Thick tunica media - over 5 layers of smooth muscle
Tunica adventitia blends in with surrounding CT
What are the types of capillaries?
Continuous
Fenestrated
Discontinuous
Describe continuous capillaries
Most capillaries
Variably permeable
Describe fenestrated capillaries
Porous
Can be open or closed
Open fenestrae in kidney
Closed fenestrae in GI
Describe discontinuous capillaries
Sinusoids
Large pores
With or without basal lamina
Describe the 3 layers found in a muscular artery
T intima - fenestrated, elastic lamina
T media - smooth muscle and elastic fibres
T adventitia - collagen and elastic fibres
What lines lymphatic vessels? What structure are they missing? Do they have valves?
Endothelium (simple squamous)
Basal lamina
Yes
