BIOL 208 Lecture Notes - Lecture 17: Vasomotor Center, Sympathetic Nervous System, Vasomotor
Document Summary
Circulatory shock decreases to point where body tissues do not receive enough blood supply and therefore not enough available o2. ** occurs when either, blood volume or co or pr drops/decreases and therefore bp. Peripheral resistance - resistance against blood vessels. Kinds of shocks if lose more than 900 ml, these systems don"t work. Hypovolemic - lose amount of blood or dehydrated and bp drops b/c less volume. Vascular - blood volume normal but massive vasodilation. Pressure in bp drops eve if volume is normal. Parasympathetic (slow down hr but accelerate other gi tract functions) and sympathetic (opposite of parasympathetic) behave antagonistically. Blood vessels are not doubly innervated innervated by sympathetic nervous system sympathetic fibers constantly send stream of mild impulses. Vasomotor center- neurons from here provide impulses to have basic contraction if slows down - luminal diameter of blood vessels increase. Anaphylaxis - *** systemic allergic reaction w/ body wise vasodilation (result of widespread histamine release)