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A&P Chap 13 Mar/Bart
A&P
Question | Answer |
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Arteriole | A small arterial branch that delivers blood to a capillary network |
Arteries | Blood vessels that carry blood away from the heart and toward a peripheral capillary |
Capillary | Small blood vessels, interposed between arterioles and venules, whose thin walls permit the diffusion of gases, nutrients, and wastes between the plasma and interstitial fluids |
Venule | Thin-walled veins that receive blood from capillaries |
Tunica | A layer or covering; in blood vessels: tunica externa, the outermost layer of connective tissue fibers that stabilizes the position of the vessel; tunica interna, the innermost layer, consisting of the endothelium plus an underlying elastic membrane; tuni |
Vasoconstriction | A reduction in the diameter of arterioles due to contraction of smooth muscles in the tunica media; elevates peripheral resistance; may occur in response to local factors, the action of hormones, or stimulation of the vasomotor center |
Vasodilation | An increase in the diameter of arterioles due to the relaxation of smooth muscles in the tunica media; reduces peripheral resistance; may occur in response to local factors, through the action of hormones, or following decreased stimulation of the vasomot |