BIOL 240 Lecture Notes - Lecture 23: Brainstem, Hypothalamus, Acetylcholine
Document Summary
Networks of successive anterior rami that exchange fibers (crisscross and redistribute) Thoracic anterior rami do not form nerve plexus. Each nerve of the plexus contains fibers from several different spinal nerves. Fibers from each ventral ramus travel to the body via different routes and braches. Phrenic nerve: from c3-c5 (cervical and brachial plexuses) Innervates diaphragm: neck injuries are so dangerous, can stop breathing due to respiratory arrest. Formed by ventral rami of spinal nerves: c5-t1. Motor: innervates deltoid and teres minor: deltoid: abducts, teres: laterally rotate. Complex motor system of nerves that governs involuntary actions. Works with somatic nervous system to regulate normal internal functions. Involuntary: pre and post ganglionic, uses two motor neurons to increase neural communication and control, neuronal convergence, neuronal divergence. Parasympathetic division: routine maintenance, rest and digest. Sympathetic division: mobilization and increased metabolism, fight, flight, fright.
