Term
Three types of capillaries |
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Definition
Continuous, Fenestrated, and Sinusoidal |
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Term
Capillaries that have no gaps between endothelial cells less permeable to large molecules than other capillaries located in the nervous system and muscle |
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Definition
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Term
Capillaries that have endothelial cells with small pores highly permeable located in intestinal villi, ciliary process of the eye, choroid plexus of the CNS, and the glomeruli in the kidney |
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Definition
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Term
Capillaries that are the largest in diameter than the other two larger pores than the others occur in endocrine glands where large molecules must cross capillary wall |
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Definition
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Term
Substances cross capillary walls by: |
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Definition
diffusing through endothelial cells, fenestrae, and crossing between endothelial cells |
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Term
What kinds of molecules diffuse though the capillary membranes? |
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Definition
lipid soluble and small water soluble molecules |
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Term
How do large substances pass through the capillary membrane? |
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Definition
by fenestrae or gaps between the endothelial cells |
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Term
What does not readily pass through capillary walls? |
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Definition
RBCs and large water soluble molecules (Proteins) |
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Term
Where are capillary networks the most numerous and extensive? |
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Definition
in highly metabolic tissues like the lung, kidneys, liver, and skeletal and cardiac muscles |
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Term
What do the capillary networks in skin function as? |
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Definition
heat loss and thermoregulation |
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Term
What are the capillary networks in muscle responsible for? |
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Definition
nutrient and waste product exchange |
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Term
Why do veins have valves? |
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Definition
do not have smooth muscle to move the blood so function to keep the blood from flowing back |
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Term
What are most blood vessels innervated by? |
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Definition
unmyelinated sympathetic nerve fibers |
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Term
What are the nerves in the penis and clitoris innervated by? |
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Definition
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Term
What blood vessels have the greatest innervation? |
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Definition
arterioles and small arteries |
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Term
What do lymphatic vessels do? |
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Definition
carries fluid away from tissues |
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Term
What are lymphatic vessel's cells made of? |
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Definition
simple squamous epithelium which are attached loosely and slightly overlay each other |
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Term
What tissues are lymph vessels NOT located? |
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Definition
CNS, bone marrow, and non vascular tissue (cartilage, epidermis, cornea) |
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Term
Compression of the lymphatic vessels moves the lymph? What is this compression due to? |
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Definition
contraction of skeletal muscles, contraction of smooth muscles of the lymph vessels, and changes in the thoracic pressure during respiration |
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Term
What do lymph nodes function as? |
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Definition
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Term
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Definition
occurs when laminar flow (normal flow) becomes interrupted |
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Term
what causes the turbulent flow? |
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Definition
constriction, branch , or rough surface |
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Term
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Definition
measure of force exerted by blood against a vessel wall |
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Term
What are the ways to measure blood pressure? |
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Definition
Cannula (direct, very painful, right in artery) and ausculatory (indirect, what we mostly use) |
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Term
Where is most of the blood volume? |
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Definition
in veins, referred to as capacity vessel cause they can dilate arteries = restriction vessels |
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Term
what controls blood flow to each region of the body? |
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Definition
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Term
What regulates local blood flow through tissues? |
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Definition
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Term
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Definition
the difference between systolic and diastolic |
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Term
What are the two major factors affect pulse pressure? |
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Definition
stroke volume and vascular compliance |
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Term
What can pulse be used to monitor? |
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Definition
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Term
what does a weak pulse indicate? |
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Definition
decreased stroke volume or increased arterial constriction |
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Term
What is capillary exchange? |
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Definition
major process of nutrient and wast product exchange through diffusion |
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Term
At the arterial end of the capillaries in the interstitial space, what causes the fluid to move from the capillary? |
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Definition
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Term
What force moves fluid into the capillary? |
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Definition
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Term
What is the concentration of small molecules interstitial fluid and blood? concentration of proteins? |
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Definition
same: less in interstitial fluid because size of proteins |
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Term
What is blood colloid osmotic pressure? |
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Definition
pressure produced by plasma proteins |
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Term
What is the relationship of blood colloid osmotic pressure between the blood and interstitial fluid? |
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Definition
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Term
At the arterial end of the capillary, what forces are moving the fluid out of the capillary? |
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Definition
blood pressure and negative pressure in the interstitial space |
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Term
What is the net movement of fluid at the arterial end? |
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Definition
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Term
What effect does the increase in osmotic pressure have at the venous end? |
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Definition
a net movement of fluid into the capillaries |
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Term
What percentage of fluid leaves the arterial and reenters at the venous end? |
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Definition
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Term
What percentage of fluid enter the lymphatic vessels? |
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Definition
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Term
What does the dilation of the precapillary sphincter cause? |
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Definition
increase in pressure that forces fluid into the interstitial space |
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Term
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Definition
how much blood is returning back to the heart |
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Term
How does vasodilation affect preload? severe dilation? |
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Definition
more preload; less preload, too much dilation blood just stays |
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Term
What are capillary structure primarily regulated by? |
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Definition
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Term
What are vasodilator substances? |
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Definition
carbon dioxide, lactic acid, adenosine, AMP, ADP, EDFR, potassium ions, hydrogen ions produced as rate of metabolism increases |
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Term
What are the functional characteristics of a capillary bed? |
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Definition
lack of nutrients serves as role to regulate local flow lack of oxygen and other nutrients result in relaxation of smooth muscle cells of precapillary sphincters |
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Term
Why do we have cyclic flow through capillaries? |
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Definition
you need enough time for nutrients to be released and waste products picked up which is due to the periodic contraction/dilation of precapillary sphincters called vasomotion |
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Term
What happens to the capillaries long term if the metabolic activity increases? |
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Definition
diameter and number of capillaries increases |
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Term
Capillary exchange can also result from what two processes? |
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Definition
cyclic dilation and constriction of precapillary sphincter |
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Term
What does the dilation of the precapillary sphincter cause? |
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Definition
increase in pressure that forces fluid into the interstitial space |
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Term
What does blood flow function in the kidneys as? |
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Definition
to regulate water balance, pH, and eliminate waste products |
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Term
What does blood flow in the liver function as? |
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Definition
delivers nutrients from small intestine for metabolism |
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