Chapter 14: The Autonomic Nervous System Flashcards
the somatic nervous system controls subconscious control of ___
skeletal muscles
the SNS pathway consists of ___ and ___ motor neurons
upper; lower
lower motor neurons may be controlled by what 2 things?
- reflexes based in the CNS
2. upper motor neurons in nuclei of brain or primary motor cortex
the autonomic nervous system controls ___
visceral function (mostly outside our awareness)
motor neurons of CNS synapse on visceral motor neurons on ____ganglia
autonomic
the integrative centers of the hypothalamus are located in the ___
hypothalamus
2 motor neurons in sequence; control visceral effectors:___and ___ neurons
preganglionic and ganglionic
preganglionic neurons have cell bodies in the ___ and ___
brain and spinal cord
preganglionic neurons are part of the ___ reflex arcs
visceral
most activities of preganglionic neurons represent ___ reflex responses
direct
preganlionic neurons leave the CNS and synapse with ___
ganglionic neurons
ganglionic neurons are ___ neurons
visceral motor neurons
ganglionic neurons have cell bodies in ___
peripheral autonomic ganglia
ganglionic neurons innervate __ in cardiac & smooth muscle, glands, adipose tissue
visceral effectors
the 2 divisions of the autonomic nervous system
- sympathetic
2. parasympathetic
the sympathetic and parasympathetic nervous systems usually have ___ effects
opposing
is it possible for some structures to only be innervated by one division of the autonomic nervous system?
yes
both divisions of the autonomic nervous system influence a third autonomic nervous division called __-
enteric nervous system (ENS)
the sympathetic division is typically active during ___
exertion, stress, emergency
axons of the sympathetic division emerge from cell bodies in the ___ and ___ segments of the spinal cord (____ specific vertebrae)
thorarcic; lumbar; T1-L2
sympathetic axons innervate ganglia close to the ___
spinal cord
sympathetic axons innervate what type of ganglia?
sympathetic chain ganglia
the parasympathetic division controls __
resting conditions
parasympathetic axons emerge from ___ and ___ segments of the spinal cord
brainstem; sacral
parasympathetic axons innervate ____ ganglia
target organ
parasympathetic fibers are carried in cranial nerves ____ (4) and sacral nerves ___ (3)
- III, VII, IX, X
2. S2, S3, S4
what is the enteric nervous system?
extensive network of neurons and nerve networks in walls of digestive tract
the enteric nervous system initiates/coordinates many complex local visceral reflexes with no ___
CNS input
the enteric nervous system is influenced by the ___ divisions
sympathetic and parasympathetic
what are sympathetic chain ganglia?
interconnected ganglia on each side of the vertebral column
what do collateral ganglia innervate?
innervate abdominopelvic tissues
what is the adrenal medullae?
modified sympathetic ganglia
what is the function of the adrenal medullae?
secrete neurotransmitters into bloodstream that acts as hormones
neurons of the sympathetic division have short __ and long __
preganglionic fibers; postganglionic fibers
7 responses to increased sympathetic activity
- heightened mental alertness
- increased metabolic rate
- decreased digestive and urinary functions \
- activation of energy reserves
- dilation of respiratory passageways: increased breathing
- increased heart rate and blood pressure
- activation of sweat glands
typical parasympathetic preganglionic fiber synapses on __ to __ ganglionic neurons
6-8
parasympathetic preganglionic fibers can synapse on what 2 types of ganglia?
- terminal ganglia
2. intramural ganglia
terminal ganglia are typically located __
near target organ
T/F terminal ganglia are usually paired
true
intramural ganglia are loated __
embedded in tissues of target organs
intramural ganglia typically consist of ____ of ganglion cells
interconnected masses and clusters
which cranial nerve is associated with ciliary ganglia?
CIII
what is the target organ of the ciliary ganglia?
intrinsic eye muscles
which cranial nerve is associated with the pterygopalatine and submandibular ganglia?
CN VII
what are the target organs of the pterygopalatine and submandibular ganglia/
nasal glands, tear glands, salivary glands
which cranial nerve is associated with the otic ganglia?
CNIX
what are the target organs of the otic ganglia?
parotid salivary glands
which cranial nerve is associated with the intramural ganglia?
CN X (and also pelvic nerves)
5 responses to increased parasympathetic activity
- decreased metabolic rate
- decreased heart rate and blood pressure
- increased secretion by salivary and digestive glands
- increased motility and blood flow to the digestive tract
- stimulation of urination and defecation
innervation in the sympathetic division is the same on both sides of the body (T/F)
true
____ of each spinal nerve carries postganglionic sympathetic fibers to body wall and limbs
gray rammus communicans
in the head and neck, postganglionic fibers from ___ sympathetic ganglia go to areas supplied by cranial nerves ___ (4)
superior cervical; III, VII, IX, X
what are the 3 groups of splanchic nerves?
- cardiopulmonary
- abdominopelvic
- pelvic
cardiopulmonary splachic nerves are __ fibers to __
postganlionic; heart/lungs
preganglionic abdominopelvic splanchnic nerves synapse on __
collateral ganglia: celiac superior and inferior mesenteric
postganglionic abdominopelvic splanchnic nerves go to the __
abdominopelvic viscera
pelvic splanchnic nerves are ___ fibers below __ that go to __
postganglionic; L2; pelvic structures
the vagus nerve is part of the ___ division
parasympathetic
the vagus nerve is cranial nerve ___
X
the vagus nerves provides ___% of all parasympathetic outflow
75
vagal nerves intermingle ___ fibers, forming nerve ___
sympathetic; plexuses
sacral preganglionic fibers carry sacral ____ output
parasympathetic
do sacral preganglionic fibers join spinal nerves?
no
the sacral preganglionic fibers form distinct ___ nerves
pelvic
the pelvic nerves innervate intramural ganglia in the __(4)
kidneys, bladder, distal large intestine, sex organs
sympathetic division can trigger __ reflexes with specific __-
local; effectors
the sympathetic division can be activated in its entirety by a process called __
sympathetic activation
sympathetic activation occurs by releasing ___ at peripheral synapses and distributing __ and ___ throughout the body
norepinephrine; NE and epinephrine
sympathetic activation is controlled by centers in the ___
hypothalamus
sympathetic activation occurs during __
crisis
are the effects of sympathetic activation limited to peripheral tissues?
no
sympathetic activation also alters ___ activity
CNS
does the parasympathetic division release neurotransmitters into the bloodstream?
no
why does the parasympathetic division not do division-wide system activation?
it does not release neurotransmitters into the bloodstream
parts of the parasympathetic division are ___ continously
active
activities of the parasympathetic division are ___ responses to conditions within ___
reflex; specific structures or regions
the effects of the parasympathetic division center on ___ (3)
- relaxation
- food processing
- energy absorption
the parasympathetic division is also called the __-
anabolic system
the parasympathetic division increases ___ in the blood
nutrients
which division is associated with growth and development?
parasympathetic
excess nutrients in the parasympathetic division are stored as ___
lipids or glycogen for energy reserve
the preganglionic fibers in the parasympathetic division are __ and the post fibers are __
long; short
location of the PNS ganglia
typically intramural
NE and E bind to ___ in target cell plasma membrane
adrengic receptors
what are the 2 types of adrengic receptors?
alpha receptors and beta receptors
NE stimulates __- receptors more than ___ receptors
alpha more than beta
E binds to __ receptors
alpha and beta
are epinephrine and norepinephrine very similar neurotransmitters and hormones?
yes
epinephrine has more effect on your __
heart
norepinephrine has more of an effect on your ___
blood vessels
neurotransmitter release in ANS effects last __
longer
adrenal release 3x more ___ than __
epinephrine than NE
during sympathetic activation, ___ receptor effects predominate
beta
alpha receptors activate __ of the PM
G proteins
activation of G proteins what 2 types of responses?
excitatory and inhibitory
beta receptors are typically stimulated by ___
Epinephrin
beta receptors are found in what part of the body?
organs, skeletal muscle, lungs, heart, liver
stimulation of beta receptors and G protein activation change target cell’s ____ activity
metabolism
what are the 3 types of Beta receptors?
B1, B2, B3
parasympathetic fibers release ___
acetylcholine (Ach)
the parasympathetic division has 2 types of ___ receptors
cholinergic
what are the 2 types of cholinergic receptors?
nicotinic and muscarinic
nicotinic receptors are located on all postganglionic neurons on ___ cells and at ___ of skeletal muscle fibers
adrenal medullae; neuromusclular
nicotinic receptors are ___ (excitatory/inhibitory)
excitatory
nicotinic receptors are stimulated by ___
nicotine
muscarinic receptors are ___ coupled receptors
G-protein
where are muscarinic receptors located in the parasympathetic division?
neuromuscular and neuroglandular junctions
where are muscarinic receptors located in the sympathetic division?
few cholinergic junctions
which has more long-lasting effects? Nicotinic or muscarinic?
muscarinic receptors
muscarinic receptors are stimulated by ___
muscarine
what is muscarine?
toxin produced by poisonous mushrooms
what nervous system adjusts the activities of the digestive, cardiovascular, respiratory, and reproductive systems sunconsciously
ANS
T/F ANS output impacts virtually every body system
true
what is autonomic tone?
continuous level of spontaneous ANS activity
the autonomic tone is maintained even without ___
stimuli
the dual innervation receives instructions from ___
both ANS divisions
effects of dual innervation can be ___ or ___
complementary or opposite
in organs with only sympathetic innervation, responses vary depending on ____
receptor type stimulated
___ innervation exists in the heart
dual
in the heart, the ANS has opposing effects on ____ function
pacemaker
_____ (neurotransmitter) reduces heart rate
ACh
_____ (ANS division) reduces heart rate
parasympathetic
_____ (neurotransmitter) raises heart rate
NE
____ (ANS division) raises the heart rate
sympathetic
at rest which ANS division effects dominate?
parasympathetic
interoceptors monitor ____ and ____
visceral tissues and organs
interoceptors include 5 types of receptors ____
- nociceptors
- thermoreceptors
- tactile receptors
- baroreceptors
- chemoreceptors
most interoceptor processing is ____ (conscious/subconscious)
subconscious
most interoceptor processing occurs in the ___ of the spinal cord and the ___ in the brainstem
nuclei; solitary nuclei
baroreceptors are ____ receptors that monitor ___ changes
stretch; pressure
baroreceptors are ____ branching into ___ tissues
free nerve endings; elastic
baroreceptors are found in (3)
- hollow organs
- blood vessels
- tubes are respiratory, digestive, and urinary tracts
how do baroreceptors work?
changes in pressure distort dendritic branches, altering the rate of action potentials
baroreceptors monitor blood pressure in what major vessels?
- carotid artery at the carotid sinus
2. aorta at the aortic sinus
which receptors regulate cardiac function, adjust blood flow to vital tissue?
baroreceptors
which receptors monitor the degree of lung expansion?
baroreceptors
information from baroreceptors in the lungs is sent to ____ centers in the ___ (part of brain)
respiratory rhythmicity; medulla oblongata
which receptors trigger reflexes in the digestive and urinary tracts?
baroreceptors
chemoreceptors are ___ that detect changes in ___
specialized neurons; concentrations of chemicals
chemoreceptors have a role in reflexive control of ___ and ___ function
respiratory and cardiovascular
what are the 3 locations of chemoreceptors?
- medulla oblongata
- carotid bodies
- aoritic bodies
in the medulla oblongata, chemoreceptors monitor ___ and ___ in CSF
pH and PCO2
chemoreceptors are located in what part of carotid arteries?
near the origin of internal carotid arteries
in carotid arteries, chemoreceptors monitor ___, ___ and ___ in arterial blood
pH; PCO2, PO2
where are chemoreceptors located in aortic bodies?
between branches of the aortic arch
in aortic bodies, chemoreceptors monitor __, __, and __
pH, PCO2, PO2
ANS activity is controlled by __ in the __
nuclei in the brainstem
more complex reflexes are coordinated by centers in the __ (Part of the brain)
medulla oblongata
medullary centers are regulated by ___ (ANS headquarters)
hypothalamus
examples of reflexes coordinated by the medulla oblongata
cardivascular, respiratory, digestion
the ___ interacts with other areas of the brain and links their activity/autonomic functions
hypothalamus
there is continual ___ between higher brain centers, hypothalamus, and brainstem
feedback
both SNS an ANS have ___ organization
parallel
sensory pathways may carry information to both __ and __
SNS and ANS
higher levels of integration involve ___
brainstem