Intro and Types of Vessels Flashcards
Afferent definition
carrying toward a central structure
Efferent definition
carrying away from a central structure
Arteries function
vessels that carry blood away from the heart
Arterioles function
major point of control over how much blood an organ or tissue receives
Capillaries function
connects the smallest arteries to the smallest veins
Venules function
collect deoxygenated blood from the capillaries and transport it to larger veins
Veins function
carries blood back to the heart
What tissue does the tunica intima contain?
simple squamous epithelium and a sparse layer of loose connective tissue
What tissue does the tunica media contain?
smooth muscle, collagen, and sometimes elastic tissue
What tissue does the tunica externa contain?
loose connective tissue
Which tunic touched the blood?
tunica intima
endothelium
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What is the vasa vasorum
network of smaller vessels serving the larger one
Structural differences between veins and arteries
Elasticity definition
ability of a blood vessel to stretch and return to its original shape
Contractility definition
ability of blood vessel walls to change diameter
Vasoconstriction definition
narrowing of a vessel
What causes vasoconstriction
smooth muscle of the tunica media contracts
Vasodilation definition
widening of a vessel
What causes vasodilation
relaxation of the smooth muscle
What can signal smooth muscles in arteries to contract?
What are the 3 main types of arteries?
conducting (large) arteries, distributing (medium) arteries, resistance (small) arteries
Sensory structures of arteries
carotid sinuses, carotid bodies, aortic bodies
Structure of capillaries
What are the 3 types of capillaries?
continuous, fenestrated capillaries, sinusoids
Where are each of the 3 capillaries found?
continuous - skeletal muscles, lungs, brain
fenestrated - kidneys, endocrine glands, small intestine
sinusoids - liver, bone marrow, spleen
Capillary bed definition
Precapillary sphincter definition
smooth muscle cell around the entrance of a capillary; acts as a valve controlling blood flow into capillary networks
Collaterals definition
backup blood vessels that allow for secondary blood pathways
Anastomoses definition
point of convergence between two blood vessels other than capillaries
Angiogenesis definition
process of creating new blood vessels
What are the key characteristics of veins?
thin-walled and flaccid
What are the 3 types of veins
- postcapillary venules
- medium veins
- large veins
Purpose of venous valves
prevent backflow of blood
How do venous valves work
Distribution of blood throughout the body
Describe arterisclerosis
stiffening and loss of elasticity in arterial walls
Describe cardiovascular accidents
sudden interruption of blood flow to the brain
Describe aneurysm
weak point in an artery or the heart wall that forms a bulging sac that may rupture
Describe varicose veins
pooling of blood in the lower limbs due to standing for long periods
Order the vessels from largest to smallest
arteries, veins, arterioles, venules, capillaries
