Chapter 4 Part II Flashcards
blood flow into capillaries is controlled by: (4)
metarterioles
AVA’s
lumen size of terminal arteriole
pre-capillary sphincters
cells are a single layer of flattened endothelial cells
capillary structure
_______ vesicles form tiny pockets through cytoplasm (in capillary) that function to move ______
pinocytotic
large molecules
cell junction btwn endothelial cells of capillaries are ______ , which function to move MACROmolecules and allow for ______
fasciae occludens
cell movement
MC type of capillaries are ________, which are found (3)
continuous capillaries
muscle
CT
many organs
often considered to be residual mesenchyme cells
- numerous on capillaries and venules
- can secrete basement membrane and matrix components
- CAN DIVIDE*
pericytes
pericytes can change into: (3)
endothelial cells
smooth muscle
fibroblasts
functions of pericytes (2)
healing
regulate blood flow (influence lumen size)
modified continuous capillary in CNS have ______ INSTEAD OF fasciae occludes
barrier regulation by endothelium but influenced by astrocytes
zonula occludens
location of fenestrated capillaries (3)
pancreas
intestines
endocrine organs
_____: pores with thin protein diaphragm containing 8 fibrils that function to allow for ______ of molecules and cells
fenestrated capillaries
greater movement
capillaries that are found in: bone marrow liver spleen lymphatic organs certain endocrine organs
sinusoidal capillaries
structure of sinusoidal capillaries
enlarged diameter
many large fenestra with NO protein diaphragm
function of sinusoidal capillaries
enhanced exchange between blood and tissue
Veins are similar to arteries because have ______
3 tunics
veins are DIFFERENT than arteries because (3):
not as uniform in structure
often larger
more veins
two flaps of tunica intima and fibroelastic CT
valves
functions of valves:
1 protection by preventing ________
2 works with _______ to keep blood moving
backflow
skeletal muscle
venules are determined by ______ NOT diameter
tunics
postcapillary venules have NO ____ OR _____, and a _______ with endothelium (small amount of CT and numerous pericytes)
tunica media
tunica adventitia
tunica intima
collecting venules have _____ with ENDOTHELIUM and small amount of CT, NO _______ and _____ with CT, fibroblasts and some pericytes
tunica intima
tunica media
tunica adventitia
muscular venules have ALL 3 TUNICS: ______ is incomplete ______ layer
tunica media
smooth muscle
an incomplete tunica media allows products of inflammation through to loosen endothelial cell junctions so will end up with _______
leaky venules
_____ are similar to venules except a COMPLETE TUNICA MEDIA
small veins
tunica intima of _______ is composed of endothelium, basal lamina, CT with reticular fibers, sometimes elastic fiber network (NO IEL)
medium veins
______ of medium veins is composed of smooth muscle, collagen, fibroblasts
tunica media
______ in medium veins is usually THICKEST layer; CT with collagen and elastic fibers and a few smooth muscles cells; vasa vasorum is possible
tunica adventitia
_____ in large veins is very similar to medium veins
tunica intima
______ in large veins is complete, but THIN
tunica media
_____ is usually the thickest layer in LARGE veins
tunica adventitia
exceptions to typical structure of veins-
in superficial veins of legs, ______ is WELL DEVELOPED
tunica media
exceptions to typical structure of veins-
in pulmonary veins, _______ is WELL DEVELOPED
TUNICA ADVENTITIA- some ____ muscle close to ____
tunica media
cardiac muscle close to heart
exceptions to typical structure of veins-
in vena cava- TUNICA ADVENTITIA- some ____ close to _____
cardiac muscle close to heart
exceptions to typical structure of veins- in IVC
tunica adventitia has some _______ close to _____ and some LONGITUDINAL smooth muscle
smooth muscle close to heart
enlarged and winding superficial veins in legs
varicose veins
possible causes of varicose veins (3)
loss of skeletal muscle tone around the veins
degeneration of vessel wall
valve incompetence
varicose veins in lower esophagus; common in alcoholics, cause by portal HTN
esophageal varices
varicose veins at the end of the anal canal
hemorrhoids
