BIOL355 Lecture Notes - Lecture 29: Simple Squamous Epithelium, Smooth Muscle Tissue, Blood Vessel
21 Apr 2017
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Document Summary
Composed of smooth muscle and or elastic fibers. Regulate blood flow from cap to tissues. Elastic allows blood vessels to stretch and recoil. Carry blood at low pressure, thin walls and can collapse readily. Tiny vessels that connect smallest arteries (arterioles) to smallest veins, venules. Just large enough to permit the flow rbcs. Systolic pressure increase pressure in blood vessels during ventricle contraction. Diastolic pressure- decrease pressure in blood vessels when ventricles relax. Passive filling atrial contraction ventricular contraction ventricle relaxation. Increase resistance of blood flow due to decreased elasticity of blood vessels especially the aorta increased stiffness (fragmented elastic and cross-linked collagen fibers) Increased resistant due to blockage of arteries atherosclerosis. Decrease in the number, strength and elasticity of heart muscle cells. Heart valves may become calcified (increase stiffness and increase leakiness) Increase lipofuscin content in remaining cardiac cells: beginning by age 60 there is a pronounced decrease in number of pacemaker cells in the.
