140 terms

CH. 17 ANS

ANS autonomic division
function of autonomic nervous system
-regulates body temperature
-coordinates the cardiovascular, respiratory, digestive, excretory, and reproductive functions
routine physiological adjustments to systems are made by the ANS operating at the _______ level.
-subconscious level
major ANS divisions are _____ and _____
ans is generally always ____
ie. -can activate or inhibit an organ
-releases neurotransmitter
- causes short term changes
what 4 regions of the brain effect ANS regulatory activites
-limbic system
-cerebral cortex
brain region which is headquarter of autonomic function
the ans like the sns has ___ and ____ neurons
-afferent and
in ANS afferent pathways originate in _____ _____.
-visceral receptors
in ANS efferent pathways connect to _____ _____
-visceral effector organs
visceral motor neurons in the CNS aka _____ ______
-preganglionic neurons
cell bodies of ganglionic neurons are located in ______ _____ outside the ____
-autonomic ganglia outside the CNS
preganglionic neurons in the CNS send axon (PG fibers) to synapse on ______ _____
-ganglionic neurons
sympathetic division and parasympathetic division
-2 major subdivisions in the ANS
ans division which is aka fight or flight system
-thoracolumbar (sympathetic) division
what forms the thoracolumbar divison
-visceral efferents from the thoracic and lumbar segments
sympathetic division or
division that generally stimulates tissue metabolism, increases alertness, and prepares the body to deal with emergencies
-sympathetic division
form the craniosacral (parasympathetic division)
-visceral efferents leaving the brain stem and sacral segments
rest and response system aka
-craniosacral (parasympathetic) division
division that conserves energy and promotes sedentary activities
-parasympathetic division
affects target organs via neurotransmitters
-sympathetic and parasympathetic division
craniosacral divison aka
detremine whether the response will be stimulatory or inhibitory
-membrane receptors
neurotransmitter effects
1) all preganglionic terminals release Ach, acetylcholine and are excitatory
2)all postganglionic parasympathetic terminals release ACh and effects may be excitatory or inhibitory
3)Most postganglionic sympathetic terminals release norepinenephrine (NE) and effects are usually excitatory
widely used neurotransmitter in the ANS
terminal that release ACh and are excitatory
-preganglionic terminals
terminal that release ACh and its effects may be excitatory or inhibitory
- all postganglionic parasympathetic terminals
terminals that release norepinenephrine and effects are usually excitatory
-postganglionic sympathetic terminals
when vital organs except sweat glands recieve instruction from both sympathetic and parasympathetic fibers
-dual innervation
division that consists of preganglionic neurons between spinal cord segments T1 and L2, ganglionic neurons in ganglia near the vertebral column, and specialized neurons within the adrenal gland
-sympathetic division
sympathetic receptors include
-alpha and beta receptors
receptors sensitive to epinephrine and unresponsive to noreepinephrine and they may produce either inhibition or excitation
-beta receptors
chains that consist of about 3 cervical, 11-12 thoracic, 2-5 lumbar, and 4-5 sacral ganglia, and 1 coccygeal sympathetic ganglion in each chain
-sympathetic chains
every spinal nerve has a gray ramus that carries _____ _____ _____
-sympathetic postganglionic fibers
which 2 ganglia are the only ones that receive preganglionic fibers by white rami
-thoracic and
-superior lumbar ganglia
3 ganglia that receive preganglionic innervation from collateral fibers of sympathetic neurons
-inferior lumbar
-sacral chain ganglia
every spinal nerve receives a ____ _____ from a ganglion of the sympathetic chain
-gray ramus
signs of sympathetic stimulation
-an increase in cardiovascular and respiratory activities
-coughing reflex
coughing reflex or increase in cardio and resp activities are controlled by centers in
-medulla oblongata
ganglion that innervates the stomach, liver, pancreas, and spleen
-celiac ganglion
ganglion that innervates the small intestine and initial segments of the large intestine
-superior mesenteric ganglion
ganglion that innervates the kidney, bladder, sex organs, and terminal portions of the large intestine
-inferior mesenteric ganglion
some _________ _____ do not synapse as they pass through both the sympathetic chain and collateral ganglia
-preganglionic fibers
instead of synapsing as they pass through sympathetic chain and collateral ganglia some preganglionic fibers
-enter one of the adrenal glands and synapse on modified neurons within the adrenal medulla
how many adrenal medullae in sympathetic division
cells that synapse with modified neurons in adrenal medullae release ______ and _____ into the circulation causing ___ _____ ____ _____
-norepinephrine and
-prolonged sympathetic innervation effect
prolonged sympathetic innervation effect caused by release of
-norepinephrine and epinephrine
in a crisis the sympathetic division responds by an event called
-sympathetic activation
effects of crisis and sympathetic activation
-increased alertness
-feeling of energy and euphoria
-increased cardiovascular and respiratory activity
-general elevation in muscle tone
-mobilization of energy reserves
2 distinct results of stimulation of sympathetic division
1) release of norepinephrine or in some Ach at neuroeffector junctions
2) secretion of epinephrine and norepinephrine into the general circulation
2 classes of sympathetic receptors which are stimulated by both norepinephrine and epinephrine
-alpha receptors
-beta receptors
alpha receptors
-which respond to stimulation by depolarizing the membrane
beta receptors
-which respond to stimulation by changing metabolic activity of cells
most postganglionic fibers release________ but few release ____
which fibers innervating sweat glands of the skin and blood vessels to skeletal muscles release ACh
-most postganglionic fibers
characteristics of sympathetic division
1) 2 segmentally arranged sympathetic chains lateral to the vertebral column, 3 collateral ganglia anterior to the vertebral column, and to adrenal medullae
2) preganglionic fibers are relatively short, except for those of the adrenal medullae, while postganglionic fibers are quite long
3) extensive divergence typically occurs, with a single preganglionic fiber synapsing with many ganglionic neurons in different ganglia
4) all preganglionic fibers release ACh, while most postganglionic fibers release NE
5) effector response depends on the nature and activity of the receptor
SD has __ segmentally arranged sympathetic chains lateral to the vertebral column, __ collateral ganglia anterior to the vertebral column and to adrenal medullae
sd fibers that are relatively short
-preganglionic fibers
sd fibers that are quite long
-postganglionic fibers
sd extensive __________ typically occurs with a single preganglionic fiber synapsing with many ganglionic neurons in different ganglia
sd all preganglionic fibers release
sd most postganglionic fibers release
sd effector response depends on the
-nature and activity of the receptor
which division consists of 1)preganglionic neurons in the brain stem and in sacral segments of the spinal cord and 2)ganglionic neurons in peripheral ganglia located within or immediately next to target organs
-parasympathetic division
div with preganglionic neurons in brain stem and in sacral seg. of spinal cord
-parasympathetic division
div with ganglionic neurons in peripheral ganglia located within or immediately next to target organs
-parasympathetic division
cranial nerves that carry parasympathetic components are
-III oculomotor,
-VII facial,
-IX glossopharyngeal, and
-X vagus
cranial nerves III, VII, IX, X
-carry parasympathetic components
division which generally promotes sedentary activities "rest and repose", conserve energy
-parasympathetic division
parasympathetic fibers in the occulomotor, facial and glosspharyngeal nerves help control ______ ______ in the head, and synapse in the
-visceral structures in the head
-ciliary, pterygopalatine, submandibular, and otic ganglia
fibers in the _____ nerve supply preganglionic parasympathetic innervation to intramural ganglia within structures in the thoracic and abdominopelvic cavity
psd preganglionic fibers leaving the sacral segments form ____ ____ innervate intramural ganglia in the kidney, bladder, latter parts of the large intestine, and sex organs
-pelvic nerves
effects produced by the parasympathetic division include 1-10 and these general functions center on relaxation, food processing and energy absorption
1) constriction
2) digestive gland secretion
3) hormone secretion for nutrient absorption
4) increased digestive tract activity
5) defecation activities
6) urination activities
7) respiratory passageway constriction
8) reduced heart rate
9) pupillary constriction
10) sexual arousal
functions of parasympathetic division center on
-relaxation, food processing, energy absorption
all the parasympathetic _________ and _____ fibers release ____ at synapses and neuroeffector junctions
-preganglionic and
-postganglionic fibers
effects of release of ACh by parasympathetic pre and post ganglionic fibers are
-short lived because of the actions of enzymes at the postsynaptic membrane and in the surrounding tissues
in psd 2 different types of ACh receptors are found in
-postsynaptic membranes
which 2 types of ACh receptors are found in post synaptic membranes within psd
1)nicotinic receptors
2)muscarinic receptors
nicotinic receptors
-located on ganglion cells of both division of the ANS and the neuromuscular junctions
-exposer to Ach causes excitation by opening membrane channels
muscarinic receptors
-located at neuroeffector junctions in the parasympathetic division and those cholinergic neuroeffector junctions in the sympathetic division.
stimulation of ________ receptors produces a longer lasting effect that does stimulation of nicotinic receptors
characteristics of parasympathetic division
1)includes visceral motor nuclei associated with cranial nerves III, VII, IX, and X, and sacral segments s2-s4.
2) ganglionic neurons are located in terminal or intramural ganglia near or within target organs, respectively
3)in innervates areas serviced by cranial nerves and organs in the thoracic and abdominopelvic cavities
4) all parasympathetic neurons are cholinergic.and are further subdivided as being either muscarinic or nicotinic receptors
5)effects are usually brief and restricted to specific sites
has widespread influence, reaching visceral and somatic structures
-sympathetic division
innervates only visceral structures serviced by cranial nerves or lying within the thoracic and abdominopelvic cavity
-parasympathetic division
organs receive instructions from both divisions
-dual innervation
nerve plexuses include
-cardiac, pulmonary, espophageal, celiac, inferior memsenteric, hypogastric
in body cavities the parasympathetic and sympathetic nerves intermingle to form a series of characteristic nerve
routine adjustments in physiological systems are made by the
functions of ANS
-regulates body temp. coordinates cardiovascular, respiratory, digestive, excretory , and reproductive functions
-adjusts internal water, electrolyte, nutrient, and dissolved-gas concentrations in body fluids outside your conscious awareness
ANS differs from SNS in the ______of the neurons connecting the CNS
in ANS axon of a visceral motor neuron within the CNS innervates a 2nd neuron located in a ______ ________.
-peripheral ganglion
2nd neuron in peripheral ganglion controls the
-peripheral effector
visceral motor neurons in CNS known as
-preganglionic neurons
axons of preganglionic neurons are called
-preganglionic fibers
preganglion neurons send their axons to synapse on
-ganglion neurons
cell bodies of ganglionic neurons are located
-outside the CNS in autonomic ganglia
preganglionic fibers carry impulses _____ from the ganglion
______ ____ innervate peripheral tissues and organs, such as cardiac and smooth muscle, adipose tissue and glands
-postganglionic fibers
sympathetic division consists of the following:
-preganglionic neurons located between segments T1 and l2 of the spinal cord
-2 types of ganglion neurons in ganglia near vertebral column
-specialized neurons in the interior of the adrenal gland
the two types of ganglion neurons in ganglia near the vertebral column in the sympathetic division are
1) sympathetic chain ganglia aka paravertebral or lateral ganglia
2) collateral ganglia aka prevertebral ganglia
prevertebral ganglia in Symp. Div. aka
-collateral ganglia
paravertebral ganglia in symp. div aka
-sympathetic ganglia, or lateral
in sympathetic div. _______ ______ are short because ganglia are close to the spinal cord
-preganglionic fibers
shows extensive divergence
-sympathetic division
sympathetic division of the ANS include two a)________ chains. three b) ______ganglia and two c) ______ ________
c)adrenal medullae
preganglion neurons in sympathetic div. release ACh at
-synapses with ganglionic neurons
effector response of the sympathetic div. depends on the
-function of the membrane receptor
general functions of the parasympathetic div.
-constriction of the pupils to restrict the amount of light entering the eyes, assists in focusing on nearby objects
-secretion by digestive glands, including salivary glands, gastic glands, pancreas, liver
-secretion of hormones that promote nutrient absorption by peripheral cells
-increases smooth muscle activity along the digestive tract
-stimulation and coordination of defecation
-contraction of the urinary bladder during urination
-constriction of respiratory passageways
-reduction in heart rate and force of contraction
-sexual arousal and stimulation of sexual glands in both sexes
functions of parasympathetic division
ganglionic neurons of the parasympathetic division are situated in
-intramural ganglia or in ganglia closely associated with their target organs
parasym. div includes visceral motor nuclei in the brain stem associated with 4 cranial nerves
the parasympathetic div. innervates structures in the head and organs in the _________ and _______________ cavities
all parasympathetic neurons are
effects of the parasympathetic stimulation are usually _____ and restricted to _____ organs and sites
first neuron
-sympathetic division
terminal ganglia
collateral ganglia
sympathetic chain
-all preganglionic fibers
-suprarenal medulla
long postganglionic fiber
-preganglionic fibers to collateral ganglia
-sympathetic activation
visceral motors in the CNS
-send axons to synapse on peripherally located ganglionic neurons
splanchnic nerves
-include preganglionic fibers that go to collateral ganglia
which of the following ganglia belong to the sympathetic division of the ANS
-paravertebral ganglia
preganglionic fibers of the ANS sympathetic division originates in the
-thoracolumnbar spinal cord
the neurotransmitter at all synapses and neuroeffector junctions in the parasympathetic division of the ANS is
the large cells in the suprarenal medulla which resemble neurons in sympathetic ganglia
-release epinephrine and norephinephrine into blood capillaries
sympathetic preganglionic fibers are characterized as
-being short in lenght and myelinated
all preganglioinic autonomic fibers release ________ at their synaptic terminals and the effects are always
postganglionic fibers of autonomic neurons are usually
the white ramus communicans
-carries the preganglionic fibers into a nearby sympathetic chain ganglion