Chapter 15- Autonomic Nervous System Flashcards
What is the ANS?
A system of motor neurons that innervate smooth muscle, cardiac muscle, and glands of the body; Functions with the hypothalamus (“puppet master”) to maintain homeostasis
Autonomic activation or inhibition of body systems…
Somatic motor- voluntary- skeletal muscles
Visceral motor- involuntary - sm/card muscle tissue and glands
2 Divisions of the ANS
Sympathetic (Fight or Flight) & Parasympathetic (Rest and Digest)
Functions of Sympathetic
Fight or flight; responds to stresses (physical and emotional); increase body functions that support physical activity; Decrease digestive and urinary function
Functions of parasympathetic
Rest and digest; conserve and restore body energy; decrease body functions that support physical activity; increase digestive and urinary function; activates stomach muscles
Know somatic motor vs. autonomic motor chart in CH. 15
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Define preganglionic neuron
Soma located in the CNS
Sympathetic: lateral horn of the thoracolumbar spinal cord
Parasympathetic: brainstem or sacral spinal cord
Define postganglionic neuron
Soma located in the PNS
Autonomic ganglia are located in different places for sympathetic vs parasympathetic branches of the…
ANS
Define terminal ganglia
Part of the parasympathetic ganglia; located close to or within the wall of an organ, some located in the head but most located in the gut
because terminal ganglia are located so near the effector organ…
Preganglionic axons are long (spinal cord/brain-> ganglia)
Postganglionic axons are short (ganglia -> effector)
Preganglionic nerves=
4 cranial nerves + sacral spinal nerves
Memorize the cranial nerves in CH 15
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Parasympathetic =
Craniosacral outflow
CN III (oculomotor)= what parasympathetic function?
Pupillary constriction
Parasympathetic function of CN VII (Facial)
Lacrimal gland, salivary glands below the tongue
Parasympathetic function of CN IX (glossopharyngeal)
Parotid gland
Parasympathetic function of CN X (Vagus)
Visceral organs of the thorax and upper 2/3rds of the abdomen; 90% of preganglionic parasympathetic fibers for the whole body
2 sympathetic Ganglia
paravertebral ganglia & prevertebral ganglia
Paravertebral Ganglia (chain ganglia)
located in a vertical row to either side of vertebral column; paired
Prevertebral ganglia
located anterior to the vertebral column near the large abdominal arteries; unpaired
Because most of the sympathetic ganglia are near the spinal cord…
Preganglionic axons are short (spinal cord -> ganglion)
Postganglionic axons are long (ganglion -> effector)
Parasympathetic = \_\_\_outflow Sympathetic = \_\_\_ Outflow
Craniosacral; thoracolumbar
The Adrenal Medulla
Innermost part of the adrenal gland; highly specialized sympathetic ganglia; specialized neurons without processes; secrete hormones: norepinephrine and epinephrine (adrenaline)
Autonomic tone
balance between sympathetic and parasympathetic branches of the ANS; regulated largely by the hypothalamus
Autonomic control of the heart
Sympathetic- stimulates the heart to beat faster and harder
Parasympathetic - slows the heart down
Autonomic control of the bronchioles
Sympathetic: dilation of bronchioles
Parasympathetic: constriction of bronchioles
(sphincters in bronchioles)
Autonomic control of the GI tract
Sympathetic: sphincters close
Parasympathetic: inhibits sphincter closure
