Chapter 15
Somatic Nervous System
receives sensory input from neurons that convey sensory info for somatic senses or special senses
Autonomic Nervouse System
receives input from interocepts that monitor the internal environment
regulates cardiac muscle, smooth muscles, and glands
ANS
motor neurons functions by either increasing or decreasing activities; involuntary
ANS
always contracted when stimulated; voluntary control
SNS
Interceptors
sensory receptors found in blood vessels, visceral organs, muscles, and areas of nervous systems that monitor internal environments
location of ganglion
close to CNS and distant from visceral effectors
Vagus nerve (ANS)
mood, immune response, digestion, and heart rate; crucial bodily function
Neurotransmitter (sympathetic)
preganglion neurons release acetylcholine, postganglion neurons release nonepinephrine
Parasympathetic Neurotransmitter
preganglion neurons release ACh; postgaglion neurons release ACh
Cholingeric location
proteins in postsynatpic plasma; activated by ACh
Nicotinic Recep (skeletal muscle)
loc: sarcolemma of skeletal muscle fibers; effect: excitation then contraction
Nicotinic recep (adrenal medulla)
loc: chromaffin cells of adrenal medulla; effect: epinephrine and nonepinephrine secretion
Nicotinic recep (plasma membrane)
loc: membrane of postganglionic sympathetic and parasympathetic neurons; effect: excitation to impulse in postganglion neurons
sweat glands
innervated by sympathetic postganglion neurons
Parasympathetic
increase in salvation, lacrimation, urination, digestion, defecation
Parasympathetic
decrease in HR, airway diameter, pupil constriction
Sympathetic response last longer than parasympathetic...
sympathetic postganglion neurons diverge more extensively
Sympathetic response last longer than parasympathetic...
Nonepinephrine stays in synaptic cleft for longer time
Sympathetic response last longer than parasympathetic...
nonepinephrine and epinephrine intensify and prolonged effect
"resting and digestion"
Parasympathetic
slows down most body activity and conserve and restore body energy
parasympatheitc
Sympathetic innervation
sweat glands, arrector pili, kidenys, spleen, blood vessels, and adrenal medulla
Sympathetic (Thoracolumbar)
distribute to a wide region, spinal cord T1-L2, thoracolumbar outflow, close to CNS, short axons synapse w/ many postganglionic neurons w/ long axons
Parasympathetic (craniosacral)
head, thorax, abdomen and pelvis; S2-S4; within walls of visceral effectors, preganglion neurons w/ long axons, post gang w/ short axons
Muscarinic (sweat glands)
innervated by cholingeric sympathetic postgang neurons; increase sweating
Muscarinic (skeletal muscle)
innervated cholinegeric sympath; inhibition then relaxation then vasodilation
Adrengic receptors
integral proteins in postsynaptic membrane
a1 Andrenergic Recep
loc: smooth muscle fibers in blood vessels; excitation to contraction
A2 Andrenergic Receptor
loc: smooth muscle fibers in some vessels; inhibition to relaxation to vasodilation
b1 Andrengeric Recep
loc: cardiac muscle fiber; effect: excitation to increase force and rate of contraction
b2 Andrengic receptors
loc: airway, heart vessels, skeletal muscle, adipose tissue, liver
inhibition to relaxation; cause dilation of airways, vasodilation and relaxtion or organ walls
b2
excitation to contraction; vasoconstriction, dilation of pupil, and closing of sphincters
A1
Sympathetic System
"fight or flight"
stimulation leads to increased alertness and metabolism to be ready for emergency
Sympathetic division
sympathetic responses
dilation, kidney and GI blood vessels constrict, BP increase, liver brkdwn glycogen and adipose tissue brkdwn triglycerides
Autonomic Tone
balance between sympathetic and parasympathetic; regulated by hypothalamus
Autonomic Plexus
celiac, superior and inferior mesenteric, renal, hypogastric
Hypothalamus
major control and integration center of the ANS
Autonomic Reflex Arc (in order)
sensory receptor, sensory neuron, integrating center, motor neurons, effector
Sensory Receptor
conducts nerve impulses from sensory receptors to CNS
Integrating Center
relay signals from sensory neurons to motor neurons with most centers in hypothalamus and brain stem
Motor Neuron
conduct nerve impulses from integrating center to effectors
Effector
are smooth muscles, cardiac muscles or glands
Autonomic Dysreflexia
exaggerated response of the SNS; severe vasoconstriction, increase parasym and decrease sympath
Raynaud Phenomenon
excessive sympathetic stimulatin of the aterioles of digit