KIN 232 Lecture Notes - Lecture 1: Alpha Motor Neuron, Postganglionic Nerve Fibers, Somatic Nervous System
Document Summary
Difference between a nerve and a neuron: nerve- conduit containing a bunch of nerve cells; vary 100s to 1000s of nerve cells, neuron- has a soma (cell body), dendrites (branch receptors), axon, axon terminal (sprays out neurotransmitters) Parasympathetic ns: rest and digest: somatic: voluntary and movement of skeletal muscles. Paravertebral ganglionic chain runs parallel to spinal cord. Pre ganglionic neurons are short and post are long; opposite for pns; set up like this because in fight or flight whole body needs to respond and everything gets turned on at once. Short preganglionic neurons releasing acetylcholine as a neurotransmitter. Every postganglionic neuron releases: epinephrine except in sweat glands. Acetylcholine is neurotransmitter for pre and post ganglionic. Long preganglionic and short postganglionic because body-wide response is not necessary; sludd (salivation, lacrimation, urination, defecation, digestion: dry eye or dry mouth would elicit a response from psns. Long preganglionic allows for specific control so that not urinating every time you salivate etc etc.
