Unit 3 Quiz 5 ANTR 350

compare and contrast the somatic and the autonomic nervous systems

- somatic nervous system- - skeletal muscles, voluntary, one neuron - The part of the peripheral nervous system that transmits signals from the central nervous system to skeletal muscles, and from receptors of external stimuli, thereby mediating sight, hearing, and touch - autonomic nervous system- - smooth, cardiac, glandular tissue - Acting or occurring involuntarily, without conscious control - the brain continuously receives information from the body, and uses that information to elicit a response - 2 neurons: preganglionic and postganglionic neurons

list the two divisions of the autonomic nervous system and describe their basic functions

- sympathetic division- "fight or flight" response- increases heart rate, slows digestion, and makes other changes necessary to reach safety - parasympathetic division- "rest and digest"- slows heart rate, increase digestion, make other changes to relax the body

specify the function of the autonomic nervous system and specify what types of tissue it innervates

- visceral efferent system that controls the function of visceral organs (composed of smooth muscle, cardiac muscle, and glands) - functions without voluntary control - connects the brain to heart, lungs, sweat glands, bladder, and digestive system - the brain continuously receives information from the body, and uses that information to elicit a response - allows our body to maintain bodily functions and internal homeostasis

explain the difference between a preganglionic and postganglionic neuron

A. Preganglionic neurons- Neuron has cell body in the CNS and sends impulses to the ganglion B. Postganglionic neurons- neuron that has its cell body in the autonomic ganglion and carries impulse to the effector cells

list the four cranial nerves that carry parasympathetic nerve fibers

Cranial nerve III- oculomotor nerve- - project to the ciliary ganglia and innervate the ciliary muscles and lens of the eye - effects are pupil restriction (limit amount of light going into eye) and lens accommodation (for near vision) Cranial nerve VII- facial nerve- - project to the pterygopalantine and submandibular ganglia and innervate the lacrimal and mucosal glands of the nasal cavity and the submandibular and sublingual salivary glands. The effects are secretion. Cranial nerve IX- glossopharyngeal nerve - project to the otic ganglia and innervate the parotid salivary gland. The effects are secretion. Cranial Nerve X (vagus nerve)- are responsible for the vast majority of the body's parasympathetic output (80% to 95%). These preganglionic fibers travel to the thorax, where they project to the cardiac plexus to innervate the heart, to the pulmonary plexus to innervate the lungs, and to the esophageal plexus to innervate nearby tissues. Some even pass through the diaphragm to project into stomach wall or the celiac or mesenteric plexuses, which innervate digestive organs like the gallbladder, liver, pancreas, small intestine, and colon. The effects are to decrease heart rate and respiration and to increase digestion.

describe the effects of parasympathetic innervation to the eye, salivary glands, heart, lungs, abdominal organs, and pelvic organs a. identify which nerves provide parasympathetic innervation to these structures

a. CN III- pupil constriction (limit amount of light into eye), lens accommodation (for near/ close vision) b. CN VII- parasympathetic innervation to lacrimal gland and sublingual and submandibular salivary glands c. CN IX- parasympathetic innervation to the parotid salivary gland d. CN X- decrease heart rate, dilating bronchioles of lung, increase digestion

list the locations of the parasympathetic preganglionic and postganglionic cell bodies

a. Parasympathetic preganglionic cell bodies are located in- craniosacral region (brainstem, S2-S4 gray matter of the spinal cord) b. Parasympathetic postganglionic cell bodies are located in- intramural and terminal ganglia located on or near effector tissue (synapse!)

describe the main sympathetic pathways described below and describe where the synapse occurs in each a. pathway to the body wall b. pathway to organs of the head i. describe the effect of sympathetic stimulation to the pupil c. pathway to organs of thorax i. describe the effect of sympathetic stimulation to the heart d. pathway to organs of abdomen e. pathway to adrenal medulla

a. pathway to the body wall b. pathway to organs of the head i. describe the effect of sympathetic stimulation to the pupil c. pathway to organs of thorax i. describe the effect of sympathetic stimulation to the heart d. pathway to organs of abdomen e. pathway to adrenal medulla

specify if the following structures carry preganglionic or postganglionic axons a. white ramus communicans b. grey ramus communicans c. splanchnic nerves

a. white ramus communicans - As preganglionic sympathetic neurons only arise from the T1 through L2 region of the spinal cord, white rami communicans are only found in this region. b. grey ramus communicans - The grey rami communicantes exist at every level of the spinal cord and are responsible for carrying postganglionic nerve fibres from the paravertebral ganglia to their destination, and for carrying those preganglionic nerve fibres which enter the paravertebral ganglia but do not synapse. c. splanchnic nerves - All splanchnic nerves carry preganglionic (presynaptic) sympathetic fibers except for the pelvic splanchnic nerves that carry preganglionic parasympathetic fibers.

list the locations of sympathetic preganglionic and postganglionic cell bodies a. specify the location of the sympathetic chain (paravertebral) ganglia and the prevertebral (preaortic) ganglia

preganglionic- - thoracolumbar, meaning they are located in the thoracic and lumbar segments of the spinal cord, specifically in the lateral horn of the T1 through L2 regions - The preganglionic neurons synapse in ganglia that are much closer to the vertebral column, either within ganglia found in the sympathetic chain or plexuses postganglionic- - Postganglionic cells have their cell bodies in the ganglia and send their axons to target organs or glands. - sympathetic chain (paravertebral) ganglia- - There are two sympathetic chains, each spanning the length of the vertebral column on both the right and left sides of the vertebral column. To enter the sympathetic chain a white ramus communicans is used, which connects the spinal nerve to the sympathetic chain. - prevertebral (preaortic) ganglia- - are sympathetic ganglia which lie between the paravertebral ganglia and the target organ.