Chapter 20 Flashcards
Arteries
Convey blood from heart to capillaries; more muscular control; Have thicker walls than veins; more elastic and collagen fibers so hold their shape
Capillaries
exchange substances between blood and tissues; contain only tunica intima; thin wall allows for rapid gas and nutrient exchange
Veins
transport blood from capillaries to heart; thicker tunica externa and larger lumen; wall collapses if no blood in vessel
Lumen
Space inside a blood vessel
Tunica Intima
innermost layer of vessel wall; endothelium of simple squamous epithelium
Tunica Media
Middle layer of vessel; smooth muscle cells with elastic fibers;
Tunica Externa
Outermost layer of vessel; areolar CT; helps anchor vessel to other structures;
Elastic Arteries
Conducting arteries; largest; conduct blood from heart to muscular arteries; aorta, pulmonary trunk, common carotid, common iliac arteries
Muscular Arteries
Distributing arteries to specific body regions; muscle allows vasoconstriction; elastic tissue in 2 layers (internal elastic lamina and external elastic lamina); most named arteries (brachial and coronary arteries)
Arterioles
smallest arteries; smooth muscle usually somewhat constricted; regulate systemic blood pressure and blood flow
Capillary Characteristics
wall consists of endothelial layer on basement membrane; thin wall and small diameter are optimal for exchange between blood and tissue fluid
Continuous Capillaries
continuous lining of endothelial cells; tight junctions but no complete seal; mostly small molecule and gas exchange; muscle, skin, lungs, CNS
Fenestrated Capillaries
continuous lining but the cells have fenestrations (pores); found in areas with major fluid transport (intestine and kidney)
Sinusoids
Incomplete lining with large gaps; basement membrane is incomplete or absent; transport of large substances and even full blood cells; found in bone marrow, spleen, and some endocrine glands
Capillary Beds
Groups of capillaries functioning together; fed by metarteriole
Metarteriole
a vessel branch of an arteriole
True Capillaries
vessels branching from metarteriole
Precapillary Sphincter
smooth muscle ring at true capillary origin; relaxation permits blood to flow into capillaries;
Venules
smallest veins; merge to form veins
Small, medium and large veins
Small and medium travel with muscular arteries; large veins travel with elastic arteries
Simple Pathway
one major artery delivers blood to organ or region
Arterial Anastomosis
2 or more arteries converge to supply the same region
Venous Anastomosis
2 or more veins converge to drain the same region
Arteriovenous Anastomosis
Transports blood from artery directly to vein (shunt); allows areas to be bypassed if body is hypothermic
Portal system
2 capillary beds in sequence with each other
Angiogenesis
formation of new vessels
Regression
Return to previous state of blood vessels
Companion Vessels
lie next to each other
Atherosclerosis
progressive disease of elastic and muscular arteries; thickening of tunica intima, narrowing of arterial lumen;
Aneurysm
part of arterial wall thins and balloons out; wall more prone to rupture; can cause massive bleeding and death; most common in aorta or arteries at the base of the brain
Convey blood from heart to capillaries; more muscular control; Have thicker walls than veins; more elastic and collagen fibers so hold their shape
Arteries
exchange substances between blood and tissues; contain only tunica intima; thin wall allows for rapid gas and nutrient exchange
Capillaries
transport blood from capillaries to heart; thicker tunica externa and larger lumen; wall collapses if no blood in vessel
Veins
Space inside a blood vessel
Lumen
innermost layer of vessel wall; endothelium of simple squamous epithelium
Tunica Intima
Middle layer of vessel; smooth muscle cells with elastic fibers;
Tunica Media
Outermost layer of vessel; areolar CT; helps anchor vessel to other structures;
Tunica Externa
Conducting arteries; largest; conduct blood from heart to muscular arteries; aorta, pulmonary trunk, common carotid, common iliac arteries
Elastic Arteries
Distributing arteries to specific body regions; muscle allows vasoconstriction; elastic tissue in 2 layers (internal elastic lamina and external elastic lamina); most named arteries (brachial and coronary arteries)
Muscular Arteries
smallest arteries; smooth muscle usually somewhat constricted; regulate systemic blood pressure and blood flow
Arterioles
wall consists of endothelial layer on basement membrane; thin wall and small diameter are optimal for exchange between blood and tissue fluid
Capillary Characteristics
continuous lining of endothelial cells; tight junctions but no complete seal; mostly small molecule and gas exchange; muscle, skin, lungs, CNS
Continuous Capillaries
continuous lining but the cells have fenestrations (pores); found in areas with major fluid transport (intestine and kidney)
Fenestrated Capillaries
Incomplete lining with large gaps; basement membrane is incomplete or absent; transport of large substances and even full blood cells; found in bone marrow, spleen, and some endocrine glands
Sinusoids
Groups of capillaries functioning together; fed by metarteriole
Capillary Beds
a vessel branch of an arteriole
Metarteriole
vessels branching from metarteriole
True Capillaries
smooth muscle ring at true capillary origin; relaxation permits blood to flow into capillaries;
Precapillary Sphincter
smallest veins; merge to form veins
Venules
Small and medium travel with muscular arteries; large veins travel with elastic arteries
Small, medium and large veins
one major artery delivers blood to organ or region
Simple Pathway
2 or more arteries converge to supply the same region
Arterial Anastomosis
2 or more veins converge to drain the same region
Venous Anastomosis
Transports blood from artery directly to vein (shunt); allows areas to be bypassed if body is hypothermic
Arteriovenous Anastomosis
2 capillary beds in sequence with each other
Portal system
formation of new vessels
Angiogenesis
Return to previous state of blood vessels
Regression
lie next to each other
Companion Vessels
progressive disease of elastic and muscular arteries; thickening of tunica intima, narrowing of arterial lumen;
Atherosclerosis
part of arterial wall thins and balloons out; wall more prone to rupture; can cause massive bleeding and death; most common in aorta or arteries at the base of the brain
Aneurysm