BIOM2020 Study Guide - Final Guide: Sella Turcica, Deep Vein, Duodenum
Document Summary
Innervation of the heart: receives visceral motor innervation: vagus nerve = parasympathetic = decreases heart rate and no effect on contraction, sympathetic trunk = sympathetic = increases heart rate = increases strength of cardiac contraction. Describe the pathway of muscle impulses throughout the heart. Arteries: carry oxygenated blood away from heart; end as capillaries; mostly under high pressure. Capillaries: supply body cells with nutrients and oxygen; take away waste. Veins: return poorly oxygenated blood to heart: arteries -> arterioles -> capillaries -> venules -> veins. Tunicas: tunica intima = simple squamous epithelium; forms smooth surface of lumen, tunica media = circularly arranged smooth muscle cells; changes vessel diameter by contraction/relaxation, tunica externa = outer protective connective tissue; large veins have longitudinal muscle also. Arterial bp: blood pressure produced in ventricles; measured in mm of mercury; average = 120/180, larger arteries = higher bp; smaller arteries = lower bp.
