Blood Vessels Flashcards
_ are the delivery system of dynamic structures; begin and end at heart
blood vessels
blood vessels work with the _ system to circulate fluids
lymphatic
_ carry blood away from heart; _ carry blood toward heart
arteries; veins
_ are oxygenated (except pulmonary circulation and umbilical vessels of fetus)
arteries
_ are deoxygenated (except pulmonary circulation and umbilical vessels of fetus)
veins
_ provide direct contact with tissue cells
capillaries
capillaries directly serve _ needs
tissue
_ vessels consist of lumen
all
_ is the central blood-containing space surrounded by a wall
lumen
_ are the layers of vessel walls
tunics
tunica _ is the innermost layer; has ‘intimate’ contact with blood
intima
the _ is simple squamous epithelium; lines lumen of all vessels
endothelium
endothelium is continuous with _
endocardium
endothelium’s slick surface _ friction
reduces
the _ layer is a connective tissue basement membrane
subendothelial
tunica _ is the middle layer made of smooth muscle and elastin sheets
media
_ is decreased lumen diameter; _ is increased lumen diameter
vasoconstriction; vasodilation
tunica _ is bulkiest since it maintains blood flow and pressure
media
tunica _ is the outermost layer of wall, made mostly of loose collagen fibers, nerve fibers, and lymphatic vessels
externa (adventitia)
tunica externa is also called tunica _
adventitia
_ is a system of tiny blood vessels in larger vessels
vasa vasorum
vasa vasorum functions to nourish _ layer
outermost
_ arteries are thick-walled
elastic
elastic arteries have large, _-resistance lumen
low
elastic arteries give rise to _ arteries
muscular
elastic arteries are also called _ arteries (conduct blood from heart to medium-sized vessels)
conducting
muscular arteries are also called _ arteries (deliver blood to body organs)
distributing
muscular arteries have the _ tunica media
thickest
_ control flow into capillary beds [vasodilation-vasoconstriction of smooth muscle]
arterioles
arterioles are the _ of all arteries
smallest
arterioles are also called _ arteries (changing diameters changes resistance to blood flow)
resistance
_ is the volume of blood flowing through vessel, organ, or circulation in given period
blood flow
blood flow is measured in _
ml/min
overall blood flow is relatively _ at rest (varies at organs based on needs)
constant
_ is the force per unit area exerted on blood vessel wall by blood
blood pressure
blood pressure is expressed in _
mmHg
blood pressure is measured as _ arterial BP (large arteries near heart)
systemic
the _ (in BP) provides driving force that keeps blood flowing from higher to lower pressure areas
pressure gradient
_ is opposition to flow
resistance (peripheral resistance)
resistance measures amount of _ with blood vessel walls
friction
_ are spider-shaped stem cells
pericytes
_ help stabilize capillary walls, control permeability, and have a role in vessel repair
pericytes
_, or gaps, in capillary endothelial cells allow passage of fluids and small solutes
intercellular clefts
_ are areas where plasma membranes of adjacent cells are tightly bound (impermeable barrier)
tight junctions
_ capillaries form the blood brain barrier (totally enclosed with tight junctions; no intercellular clefts)
continuous
_ capillaries are abundant in skin, lungs, muscles, and CNS
continuous
continuous capillaries are the _ permeable
least
_ is what allows materials to pass through
permeability
_ capillaries allow for increased permeability (large pores) and made of endothelial cells with fenestrations
fenestrated
_ are covered with thin glycoprotein diaphragm
fenestrations
_ capillaries are found in areas with active filtration (kidneys), absorption (intestine), or endocrine hormone secretion
fenestrated
_ capillaries contain macrophages in lining (capture-destroy foreign invaders)
sinusoidal
_ capillaries have less tight junctions and larger intercellular clefts (incomplete basement membranes)
sinusoidal
sinusoidal capillaries have _ lumen
larger
blood flow in sinusoidal capillaries is _: allows time for modification of large molecules and blood cells passing between blood-tissue
sluggish
_ capillaries are found in the liver, bone marrow, spleen, and adrenal medulla
sinusoidal
_ are interwoven networks of capillaries between arterioles and venules
capillary beds