Term
| What are the three layers in an artery |
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Definition
| tunica interna, tunica media, tunica externa |
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Term
| What are the five type of blood vessels |
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Definition
| arteries, arterioles, capillaries, venules, veins |
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|
Term
| what does the tunica interna do |
|
Definition
|
|
Term
| What is the tunica interna made up of |
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Definition
| simple squamous cells and a basement membrane |
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Term
| What does the tunica media consist of |
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Definition
|
|
Term
| what does the tunica media allow for |
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Definition
| vasoconstriction and vasodilation |
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|
Term
| what causes vasoconstriction or vasodilation |
|
Definition
| signals from the ans and vasodilating chemicals |
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|
Term
| What does the tunica externa consist of |
|
Definition
| collagen and elastic fibers |
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|
Term
| what is the function of the tunica externa |
|
Definition
| It anchors the blood vessel to the surrounding tissue |
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|
Term
| What are the two groups of arteries |
|
Definition
| elastic and muscular/distributing |
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Term
| What type of arteries are the largest and what are some examples |
|
Definition
| elastic arteries including the aorta, common carotid artery |
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|
Term
| What type of fiber do the walls of elastic arteries contain a lot of |
|
Definition
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Term
| What do the walls of elastic fibers do when the heart pumps blood into them |
|
Definition
|
|
Term
| What do the walls of elastic arteries do when the heart relaxes |
|
Definition
|
|
Term
| What does the expansion and recoiling of elastic arterial walls do to blood flow |
|
Definition
| it helps the blood move onward |
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|
Term
| What type of arteries are medium sized |
|
Definition
| muscular/distributing arteries |
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|
Term
| What do muscular arteries branch off from |
|
Definition
|
|
Term
| What is the distinguishing factor in muscular arterial anatomy |
|
Definition
| It has a thick tunica media due to the abundance of smooth muscle fibers |
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|
Term
| Where do muscular arteries distribute blood to |
|
Definition
| skeletal muscle and internal organs |
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|
Term
|
Definition
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|
Term
| What layers do large arterioles contain |
|
Definition
| tunica interna, tunica media, tunica externa |
|
|
Term
| What layers do smaller arterioles contain |
|
Definition
| tunica interna, incomplete tunica media |
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|
Term
| What do arterioles regulate and how |
|
Definition
| they regulate blood flow into the capillaries by regulating resistance |
|
|
Term
|
Definition
| opposition to blood flow do to friction between the blood and the vascular wall |
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|
Term
| How do arterioles regulate resistance |
|
Definition
| through vasoconstriction and vasodilation |
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|
Term
| What are capillaries and what do they connect |
|
Definition
| they are microscopic blood vessels that connect arterioles to venules |
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|
Term
|
Definition
| the flow of blood from arterioles to venules through capillaries |
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|
Term
| What layers do capillaries contain |
|
Definition
|
|
Term
| What is the function of capillaries |
|
Definition
| the exchange of nutrients, wastes, and gases between blood and cells via the interstitial fluid |
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Term
|
Definition
| a complex network of capillary beds |
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|
Term
| Where are capillary beds not found |
|
Definition
| lens of eye, cartilage, epidermis |
|
|
Term
| What do arterioles empty into |
|
Definition
|
|
Term
| Where do metarterioles lead into and what are they continuous with |
|
Definition
| they lead into the capillary bed and are continuous with the thoroughfare channel |
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|
Term
| What distinguishes metarterioles from the thoroughfare channel |
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Definition
| metarterioles contain scattered muscle fibers. the thoroughfare channel only contains tunica interna |
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|
Term
| What do true capillaries branch off of |
|
Definition
| metarterioles and the thoroughfare channel |
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|
Term
| What are precapillary sphincters |
|
Definition
| rings of smooth muscle that control the flow of blood into the capillary |
|
|
Term
| What happens when precapillary sphincters contract |
|
Definition
| blood flow to capillary is decreased or stpps completely |
|
|
Term
| How often does blood flow into a capillary |
|
Definition
| intermittently at about five to ten times a minute |
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|
Term
| What is the exception to intermittent capillary blood flow |
|
Definition
| actively contracting muscles |
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|
Term
| What percentage of capillaries have blood flowing through them at any given time |
|
Definition
|
|
Term
| What are the three types of capillaries |
|
Definition
| continuous, fenestrated, sinusoid |
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|
Term
| What type of capillary is the most common and least permeable |
|
Definition
|
|
Term
| What is the arrangement of cells in a continuous capillary |
|
Definition
| they form and uninterrupted lining with only small intercellular clefts. Do not contain pores through cells |
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|
Term
| What are intercellular clefts |
|
Definition
| the spaces between neighboring endothelial cells |
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|
Term
| What are continuous capillaries permeable to |
|
Definition
| water, small lipid soluble substances, small solutes, ions |
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|
Term
| What are fenestrated capillaries characterized by |
|
Definition
| numerous oval pores in the endothelial cells |
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|
Term
| What do oval pores in fenestrated capillaries allow for |
|
Definition
| greater permeability of fluids and small solutes |
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|
Term
| Where are fenestrated capillaries found and why |
|
Definition
| intestines and kidneys, they are active sites for capillary reabsorption and filtration |
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|
Term
| What are sinusoid capillaries characterized by |
|
Definition
| large fenestrations and large intercellular clefts |
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|
Term
| What can pass through sinusoid capillaries |
|
Definition
| large substances such as hormones and red blood cells |
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|
Term
| What can pass through sinusoid capillaries |
|
Definition
| large substances such as hormones and red blood cells |
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|
Term
| Where are sinusoid capillaries found |
|
Definition
| liver, spleen, bone marrow, endocrine glands |
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|
Term
|
Definition
| stationary macrophages in the sinusoid capillaries of the liver that clean the blood as it passes through |
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|
Term
| What layers do veins typically have |
|
Definition
| tunica interna, tunica media, tunica externa |
|
|
Term
| How do veins compare arteries in terms of layers and lumen |
|
Definition
| Veins have a larger lumen and thinner walls. |
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|
Term
| Which layer is the largest in veins |
|
Definition
|
|
Term
| What are venous valves composed of |
|
Definition
|
|
Term
| What is the function of venous veins |
|
Definition
| to prevent the backflow of blood |
|
|
Term
| Why are valves necessary in some veins and not in the arteris |
|
Definition
| Veins have lower pressure |
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|
Term
| Where are venous valves usually found |
|
Definition
| in the limbs where the upward movement of blood is opposed by gravity |
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|
Term
| What vessels do venules collect blood from |
|
Definition
|
|
Term
| What do venules drain into |
|
Definition
|
|
Term
| What are varicose veins due to |
|
Definition
| leaky faulty veins that cause pooling of blood and the distension of the vein |
|
|
Term
|
Definition
| varicose veins that are located in the anal canal |
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|
Term
|
Definition
| the union of two or more blood vessel branches that service the same area |
|
|
Term
| What do anastomoses allow for |
|
Definition
|
|
Term
| What is collateral circulation |
|
Definition
| the flow of blood via an alternate route through an anastomosis during an occlusion |
|
|
Term
| What happens when blood is needed from the veins |
|
Definition
| it is diverted from them by vasoconstriction |
|
|
Term
| What is collateral circulation |
|
Definition
| the flow of blood via an alternate route through an anastomosis during an occlusion |
|
|
Term
| Which arteries do not have anastomoses |
|
Definition
|
|
Term
| Which blood vessels contain the majority of blood |
|
Definition
| systemic veins and venules |
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|
Term
| What do veins and venules serve as |
|
Definition
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