BIOL 2420 Lecture Notes - Lecture 8: Tunica Media, Smooth Muscle Tissue, Blood Vessel
8 Mar 2018
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Unit 1: cardiovascular physiology (h: arterioles, has thick smooth muscle layer (tunica media, they modify blood vessel radius, divergence of the arteries (because the goal is to get the blood to all the tissues) Because of less elastin and they"re so numerous. They can house a lot of blood at a time. Below the heart, veins and lymphatic vessels fill because of gravity (they"re volume reservoirs) Major volume reservoirs are the smaller veins (they"re elliptical in shape) Leads to edema if pooling occurs too much (decreases edv & map because of decreased venous return: neural input. Norepinephrine (from sns) binds to alpha1-adrenergic receptors (promote favourable response, contractility occurs: occurs due to decreased map (or exercise)---it then increases venous pressure, smooth muscle in veins respond to sns activity too, skeletal muscle pump: Large muscle groups compress the veins when they contract (this increases the pressure in front of the valve, so the vale opens and the blood is pushed forward)
