what consists of motor neurons that innervate smooth muscles, cardiac muscle, and glands?
autonomic nervous system (ANS)
the ANS has the ability to make adjustments to ensure optimal support for the body activities, this is done via the__________.
subconscious.
ex:Shunts blood to areas that need it and adjusts heart rate, blood pressure, digestive processes, etc.
___________ INNERVATES SKELETAL MUSCLE.
SNS
___________ INNERVATES CARDIAC MUSCLE, SMOOTH MUSCLE, AND GLANDS
ANS
ANS OR SNS?
CELL BODY IS IN CNS, AND A SINGLE, THICK MYLENATED AXON TERMINAL EXTENDS IN SPINAL OR CRANIAL NERVES DIRECTLY TO SKELTAL MUSCLE
SNS
ANS OR SNS?
PATHWAY USES A TWO-NEURON CHAIN.
1. PREGANGLIONIC NEURON
2.POSTGANGLION NEURON
ANS
THE CELL BODY IN THE CNS WITH AXON EXTENDING TO GANGLION?
PREGANGLION NEURON
(OUTSIDE OF CNS) CELL BODY SYNASPES WITH PREGANGLIONIC AXON IN AUTOMATIC GANGLION WITH NONMYLEINATED POSTGANGLIONIC AXON THAT EXTENDS TO EFFECTOR ORGAN?
POSTGANGLIONIC NEURON
ANS OR SNS?
(effect is always stimulatory)
ALL NEURONS RELAESE ACh
SNS
ANA OR SNS?
(effect is either stimulatory or inhibitory)
PREGANGLIONIC FIBERS RELEASE Ach; POSTGANGLIONIC FIBERS RELEASE NOREPINEPHRINE OR Ach AT EFFECTORS
ANS
what promtes the maintenance functions, and conserves energy?
parasympathetic division
what mobilizes the body during activity?
sympathetic division
what includes all visceral organs served by both divisions cause opposites effects (maintains homeostasis)?
dual innervation
what keeps body energy use as low as possible, even while carrying out maintenance activities?
�Directs digestion, diuresis, defecation
�Referred to as "rest-and-digest"system
parasympathetic division
ex:: person relaxing and reading after a meal
�Blood pressure, heart rate, and respiratory rates are low
�Gastrointestinal tract activity is high
�Pupils constricted, lenses accommodated or close vision
what Mobilizes body during activity?
�Referred to as "fight-or-flight" system
sympathetic division
ex:Exercise, excitement, emergency, embarrassment activates sympathetic system
�Increased heart rate; dry mouth; cold, sweaty skin; dilated pupils
�During vigorous physical activity
:�Shunts blood to skeletal muscles and heart
�Dilate
parasympathetic division can also be called _________ division.
craniosacral division
-this is because fiber originate from the brain stem and sacral regions of the spinal cord
what nerves do the preganglionic fibers run in?
oculomotor nerves (III)
facial nerves (VII)
glossopharyngeal nerves (IX)
vagus nerves (X)
what accounts for ~90% of all preganglionic parasympathetic fibers in the body?
the vagus nerves (X)
sympathetic divison can also be called ___________ division.
thoracolumbar division
this is because the preganglionic neurons are in the spinal cord segments T1-L2, forming the lateral horns of the spinal cord
This Originates from neurons in S2-S4 and serves pelvic organs and distal half of large intestine
�Axons travel in ventral root of spinal nerve
Parasympathetic Division: Sacral
This is More complex and innervates more organs than parasympathetic �Some structures are innervated only by sympathetic: sweat glands, arrector pili muscle of hair follicle, smooth muscles of all blood vessels
sympathetic division
in sympathetic division preganglionic fibers pass thru _________________________ and enter_________________________.
whate rami communicantes, sympathetic trunck ganglia
how many paravertebral ganglia are in the sympathic trunk (chain)?
23.
3-c
11-t
4-l
4-s
1-coccygeal
what has the same components as somatic reflex arcs? (receptor, sensory, integration, motor, and effector)
visceral reflex arcs
what are the two key differences between visceral and somatic reflexes?
1. viseral reflex arch has TWO consectutive neurons in the motor pathway
2. afferents fibers are viseral sensory neurons (sends info about chem changes)
what are the two major naurotransmitters of ANS?
1. Ach
2.NE (norepinephrine)
what does the job of opening ion channels, depolarizing postsynaptic cells?
nicotinic receptors
what doe sth job of either inhibitory (slows heart rate) or excitatory (increases intestinal motility) actions?
muscarinic receptors
Ach is released by 2 cholinergic fibers, what are they?
1. nicotinic receptors
2.muscarine receptors
NE is released by 2 adrenergic fibers, what are they?
1. alpha receptors
2. beta eceptors
(effects depend on which subclass of receptor predominates on target organ ~ inhibit/excitatory)
true or false:
most organs have dual innervation.
true
most visceral organs have dual innervation
�Action potentials continually fire down axons of both divisions, producing a dynamic antagonistic interaction
____________Works to precisely control visceral activity
____________ division increases heart and respiratory rates and inhibits digestion and elimination
�_____________ division decreases heart and respiratory rates and allows for digestion and discardi
antagonistic interaction, Sympathetic, Parasympathetic,Sympathetic
what is the term for a continual state of partial constriction of blood vessels?
sympathetic tone
-BP drops, sympathetic fibers fire faster to increase constriction of blood vessels= ______________
�BP rises, sympathetic fibers fire less, causing dilation of vessels= _________
-BP goes up
-BP drops
�This allows sympathetic system to shunt blood where needed
what does this:
Dominates heart and smooth muscle of digestive and urinary tract organs
�Slows the heart and dictates normal activity levels of digestive and urinary tracts
parasympathetic tone
true or false:
the sympathetic division is not able to override the effects of parasympathetic tone.
false
The sympathetic division can override the parasympathetic tone effects during times of stress.
What else does the sympathetic division do?
�Thermoregulatory responses to heat
-When body temperatures rise, sympathetic nerves:
1.Dilate skin blood vessels, allowing heat to escape
2.Activate sweat glands
-When body temperatures drop, blood vessels constrict
�Release of renin from kidneys
-increa
true or false:
the brain stem recticular formation has the most direct influence over ANS.
true.
what is the main interative center of the ANS?
the hypothalamus
=Heart activity, blood pressure, temperature of body, water balance, and endocrine activity
�Emotional responses (rage, fear, pleasure) activated through limbic system signal hypothalamus to activate fight-or-flight system
what makes it possible to have voluntary cortical control of some visceral activities?
the cerebral cortex