chapter 6 hemodynamics part 1 Flashcards
________ carry blood away from heart to body tissues
arteries
______are small arteries
arterioles
______ are microscopic vessels within tissue
capillaries
_____ are the same as veins, just smaller
venules
_____ return blood from tissues to heart
veins
______ are vessels which supply 02 and nutrients to larger arteries and veins
vaso vasorum
______ - vascular smooth muscle cells contract and decrease the size of the lumen of a vessel
vasoconstriction
______smooth cells relax and the size of lumen increases
vasodilation -
_____, the hollow center where blood flows
lumen
_______inner layer simple endothelium surrounded by a basement membrane, surrounded by an internal elastic lamina
tunica interna (aka. tunica intima) –
______ middle layer of elastic and smooth muscle fibers
tunica media –
_______outermost layer consists of elastic and collagen fibers
tunica externa (aka. tunica adventitia) –
- large arteries such as aorta, carotid arteries, common iliac artery
Elastic (Conducting)
serve as a ______ this results in a smooth flow of blood to smaller diameter vessels which could rupture if high pressure spurts of blood hit them
pressure reservoir
_______- medium-sized, thick-walled arteries, distribute blood from large arteries to body parts
Muscular (Distributing)
_____occurs when branches of two or more arteries supplying the same body region are joined
Anastomosis
an alternate route supplied by anastomosis is called _______
collateral circulation
_______very small arteries that transfer blood to capillaries
Arteriole -
function in regulating blood flow from arteries to capillaries which has a significant affect on _______
blood pressure
______ leads from the arteriole to the capillary bed, smooth muscles within the walls of the metarteriole contract and relax to regulate blood flow
Metarteriole -
the metarteriole that continues to pass right through the capillary bed is referred to as a _________
thoroughfare channel
_________ are found where the capillaries branch off the metarteriole
precapillary sphincters
_________microscopic vessels, walls consist of a single layer of squamous epithelial cells (endothelium) with a basement membrane, ie. no tunica media or tunica externa
Capillaries
________intermittent contraction and relaxation of precapillary sphincters at the metarterioles
Vasomotion -
__________which are gaps between endothelial cells
intercellular clefts
the endothelial cells have many fenestrations or ______
pores
things can cross at a ______ especially if forces promoted increased movement (i.e. high blood pressure at the site)
faster rate
Materials pass through capillary wall four (4) ways
directly across endothelial membranes
pinocytic vesicles
fenestrations
intercellular clefts
________tunica interna of endothelium
tunica media with a few scattered smooth muscle fibers and fibroblasts
small diameter
proximal venule
____________ larger lumen
possesses the tunica externa like veins
distal venule:
veins possess three coats
______- thinner than arteries
tunica interna
veins _______ - much thinner with relatively few smooth muscles and elastic fibers
tunica media
veins ______ - thickest layer consisting of collagen and elastic fibers
tunica externa
_____ are found in most veins, especially veins in the limbs and are composed of thin folds of tunica interna that form flap-like cusps
valves
Simple Diffusion most important method of solute exchange where ____________
movement is down the concentration gradient
_________ can cross the phospholipid bilayer
lipid-soluble materials
__________materials can diffuse quickly through fenestrations in the endothelial cells or through intercellular clefts
water-soluble (lipid-insoluble)
brain capillary endothelial cells are non-fenestrated and the intercellular clefts are sealed closed by tight junctions i.e._______
Blood Brain Barrier
Vesicular Transport also called ________involves pinocytosis into the endothelial cell and exocytosis out
transcytosis,
Bulk Flow Important in regulating the balance of blood and interstitial fluid volumes substances move in response to forces such as _____
blood pressure
_________states that the rates of filtration and re-absorption are almost equal
Starling’s Law of the Capillaries
a force caused by the presence of large plasma proteins, primarily ______, which pull fluid from the interstitial spaces into the capillaries
albumen
_____ is a suspension of particles in a liquid
colloid
there is a net flow of fluid out and in the capillaries about 3L of that ends up as ______
lymph
____liters of fluid filtered out of capillaries
20
____liters of fluid reabsorbed
17
___ liters enters the lymphatic system
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