Cardiovascular I and II Flashcards
what types of fibers are purkinje fibers? Why are they pale stained?
they are conductive (not contractile)
pale because glycogen and less myofibrils
what is in the tunica interna?
endothelium
subendothelial CT
internal elastic lamellae (IEL)
whats in the tunica media?
smooth muscle
elastic fibers, type III collagen (reticular) fibers, and proteoglycans
whats in the tunica adventitia?
collagen type I and few elastic fibers
nervi vascularis
vasa vasorum
lymphatics
what is the defining feature of elastic arteries?
40-70 (lots) layers of elastic lamellae in tunica media
what is the defining feature of muscular arteries?
Distinct IEL = scalloped
- 8 to 40 layers of smooth muscle (circular arrangement)
- Distinct EEL
whats a defining feature of small a.?
-3 to 8 layers of smooth muscle (circular arrangement)
what is a defining feature of arterioles?
-1 to 2 layers of smooth muscle cells
what are the three types of capillaries?
continuous/somatic
fenestrated/visceral
discontinuous/sinusoidal
how do lymphocytes get home to lymph nodes?
homing effect - slip through loose junctional complexes! - HEV!!!
what vessels are HEV?
post capillary venules
why do veins have a thick t. adventitia and a thin t. media?
adventitia is thick to support low pressure system of veins
what is super special about the large vein like the vena cava?
they have longitudinal smooth muscle bundles in the t. adventitia!!! - why = constant milking of blood into VC against gravity!
where is there no lymph present?
nervous tissue, bone marrow, cartilages
what is arteriosclerosis?
hardening of the arteries
