The Autonomic Nervous System

What are the 3 possible routes sympathetic nerves can take after entering the sympathetic trunk?

1. Synapse with ganglionic neuron at the same level. 2. Ascend or descend trunk to synapse at a different ganglion level. 3. Pass through trunk without synapsing.

How many cranial nerves emerge from the brain?

12 pair

What is the efferent pathway of the autonomic nervous system?

2 neuron chain connects CNS with effector tissue

How many spinal nerves emerge from the spinal cord?

31 pair

How many parasympathetic fibers exit the brain?

4

What nerves exit above corresponding vertebrae?

C2-C7

T/F All sympathetic axons exit the spinal cord and synapse in the paravertebral trunk.

F

What is a pneumonic for autonomic nervous system reproductive function?

Point and Shoot Parasympathetic then Sympathetic

Where do parasympathetic fibers exit the spinal cord?

S2-S4

T/F All sympathetic axons exit the spinal cord and enter the paravertebral trunk.

T

What levels are the lateral horns found?

T1-L2

What spinal nerves exit below corresponding vertebrae?

T1-L5

What do parasympathetic post-ganglionic neurons release?

acetylcholine

What is released by all pre-ganglionic axons?

acetylcholine

What is released by sympathetic post-ganglionic neurons to sweat glands?

acetylcholine

Where are the splanchnic nerves largely located?

anterior surface of aorta

Where do axons of the white matter go?

ascending to somatosensory cortex descending from motor cortex communication between left and right halves

Where are motor neurons and therefore the ventral horn and ventral roots present?

at all levels

Where are sensory neurons and therefore the dorsal and dorsal root present?

at all levels

Visceral pain afferents travel back to the spinal cord with what?

autonomic motor efferents

What are the 2 divisions of the motor efferent division of the PNS?

autonomic nervous system somatic nervous system

What neurons are unmyelinated?

post-synaptic

Where does C8 exit?

between C7 and T1

Where does C1 exit?

between the occipital bone and atlas

What makes up the central nervous system?

brain and spinal cord

Where are the pre-ganglionic neuron somas of the craniosacral division housed?

brainstem and S2-S4

Special Visceral Efferent Nerve Fibers

branchial motor axons of motor neurons derived from the branchial arches voluntary motor to skeletal muscles for chewing, facial expression, swallowing, speech functionally analogous to general somatic efferent

The effector of the autonomic nervous system is ...

cardiac, smooth muscle, and glands

What is the network of post-ganglionic axons from the superior cervical ganglion called?

carotid plexus

What is in the dorsal root ganglion?

cell bodies of sensory neurons

What is found within the central canal of the spinal ford?

cerebrospinal fluid

What are the 4 parasympathetic ganglia of the head and neck and what do they innervate?

ciliary ganglion: pupil and lens otic ganglion: parotid salivary gland pterygopalatine ganglion: lacrimal and nasal glands submandibular ganglion: submandibular and sublingual salivary gland

What is the function of the peripheral nervous system?

communication lines between CNS and the rest of the body

What is the function of the sensory afferent division of the PNS?

conducts impulses form receptors to the CNS

What is the function of the autonomic nervous system?

conducts impulses from the CNS to cardiac muscles, smooth muscles, and glands

What is the function of the motor efferent division of the PNS?

conducts impulses from the CNS to effectors (muscles and glands)

What is the function of the somatic nervous system?

conducts impulses from the CNS to skeletal muscles

What is the function of the parasympathetic division of the autonomic nervous system?

conserves energy promotes housekeeping functions during rest

What neurons are myelinated?

pre-ganglionic

What makes up the peripheral nervous system?

cranial nerves and spinal nerves

What is another name for the parasympathetic division?

craniosacral division

What are the sections of the gray matter?

dorsal horn ventral horn intermediate zone lateral horns (T1-L2)

Where are the sensory neuron soma?

dorsal root ganglion

Neurotransmitters (acetylcholine, norepinephrine) are stimulatory/inhibitory.

either; depends on synapse

What does the autonomic nervous system work closely with?

endocrine system

What does the adrenal medulla secrete?

epinephrine and norepinephrine into the bloodstream

In what part of the body is there not innervation by both sympathetic and parasympathetic?

extremities and body wall there is only sympathetic innervation

What parasympathetic cranial nerve effects various facial glands?

facial nerve (VII)

What makes up the spinal nerve?

fusion of the dorsal and ventral roots

What nerve fibers are found in both the cranial and spinal nerves?

general somatic efferent general visceral efferent general somatic afferent general visceral afferent

What parasympathetic cranial nerve effects the parotid salivary gland?

glossopharyngeal nerve (IX)

Where are the effects of the parasympathetic division?

head and body cavities

Where is the spinal cord found?

in the canal formed by vertebral foramen and intervertebral disks

Dorsal Primary Ramus

innervate joints of spinal column, muscles of back, skin of back

Ventral Primary Ramus

innervate remaining lateral and ventral structures or trunk and extremities

What is the function of the central nervous system?

integrative and control centers

The lateral horn corresponds to what?

intermediolateral cell column

Where do the spinal nerves exit?

intervertebral foramen

Where are parasympathetic fibers found?

lateral aspect of intermediate zone at levels S2-S4

Where are sympathetic fibers found?

lateral horns at T1-L2

Where do sympathetic fibers exit the spinal cord?

lateral horns form T1-L2

Where are the pre-ganglionic soma of the thoracolumbar division housed?

lateral horns of spinal cord at levels T1-L2

What is the division between the parasympathetic innervation by the cranial division and by the sacral division?

left colic flexure

In the craniosacral division, which axons are long and which ones are short?

long pre-ganglionic axons short post-ganglionic

What is the role of the autonomic nervous system and endocrine system collectively?

maintains homeostasis of cardiovascular, respiratory, digestive, urinary, and reproductive functions

What is the triad of symptoms for Horner's syndrome?

miosis ptosis anhidrosis

What is the function of the sympathetic division of the autonomic nervous system?

mobilizes body systems during activity

What kind of nerves are in the ventral root?

motor

What kind of neurons are in the ventral horn and ventral roots?

motor

What makes up the motor efferent division of the PNS?

motor nerve fibers

What is the efferent pathway of the somatic nervous system?

motor neuron soma in the the CNS and axons extends to the effector muscle (1 axon)

What makes up the white matter of the spinal cord?

myelinated axons

Where are parasympathetic ganglion located?

near target organ

How does the adrenal medulla function?

pre-ganglionic sympathetic fibers innervate secretory cells and stimulate secretion of epinephrine and norepinephrine into the bloodstream

What are the cranial nerves that carry sympathetic fibers?

none

What is released by most sympathetic post-ganglionic neurons?

norepinephrine

How many sympathetic fibers exit the brain?

o

What are the cranial nerves that carry parasympathetic autonomic fibers?

oculomotor (III) facial (VII) glossopharyngeal (IX) vagus (X)

What parasympathetic cranial nerve effects pupillary constriction and lens reshaping?

oculomotor nerve (III)

Where is the sympathetic trunk?

on each side of the spinal cord extending higher and lower than spinal levels that give rise to it

What makes up the nerve plexuses?

only ventral primary rami

What stimulates erection?

parasympathetic (norepinephrine causes vasodilation)

Where do spinal nerves S1-Co1 exit?

pass through the sacral canal and out the sacral foramina and hiatus

What parasympathetic sacral nerve(s) effect the distal colon and urogenital system?

pelvis splanchnic nerves

What is the role of the parasympathetic division of the autonomic nervous system?

performs maintenance activities and conserves body energy resting and digesting decreases heart rate, blood pressure, respiration constricts pupils activates GI and urinary function

What is the only example of sympathetic and parasympathetic divisions working toward a common goal?

reproductive function

What kind of nerves are in the dorsal root?

sensory

What kind of neurons are in the dorsal horn and dorsal roots?

sensory

Which neurons are short and which axons are long in the thoracolumbar division?

short pre-ganglionic long post-ganglionic

The effector of the somatic nervous system is ...

skeletal muscle

The autonomic nervous system include motor neurons that innervate what?

smooth muscle cardiac muscle glands

Describe the third possible route of sympathetic axons.

soma in lateral horn or spinal cord gray matter axons exit ventral root and enter spinal nerve pass through white communicating ramus to sympathetic trunk pre-ganglionic axon does NOT synapse in trunk exits trunk with one of the splanchnic nerves synapse with ganglionic neuron in one of the other sympathetic ganglia post-ganglionic axon travels to effector tissue

Describe the second possible route of sympathetic axons.

soma in lateral horn or spinal cord gray matter axons exit ventral root and enter spinal nerve pass through white communicating ramus to sympathetic trunk pre-ganglionic axon travels up or down sympathetic trunk to a different level synapse with ganglionic neuron post-ganglionic axon re-enters spinal nerve via gray communicating ramus travels with peripheral nerve to effector tissue

Describe the first possible route of sympathetic axons.

soma in lateral horn or spinal cord gray matter axons exit ventral root and enter spinal nerve pass through white communicating ramus to sympathetic trunk synapse with ganglionic neuron post-ganglionic axon re-enters spinal nerve via gray communicating ramus travels with peripheral nerve to effector tissue

What is makes up the sensory afferent division of the PNS?

somatic and visceral sensory nerve fibers

General Somatic Efferent Nerve Fibers

somatic motor axons of motor neurons for voluntary motor control of skeletal muscle

What makes the somatic nervous system?

somatic motor voluntary nerves

General Somatic Afferent Nerve Fibers

somatic sensory convey touch, pain, temp, pressure, vibration, proprioception of head

Visceral pain afferents are capable of exciting what?

somatic sensory neurons at the same spinal level

Stellate ganglion

sometimes the inferior cervical ganglion and T1 ganglion fuse

Special Sensory Afferent Nerve Fibers

special sensory convey sensory input of vision, hearing, balance, taste, and smell

What nerves fibers are found only in some cranial nerves?

special visceral efferent special sensory afferent

What connects the paravertebral trunk with other sympathetic ganglia?

splanchnic nerves

What is the role of the sympathetic division of the autonomic nervous system?

stimulates effectors during times of activity fight of flight increases heart rate, blood pressure, respiration dilates pupils slows GI and urinary function

The autonomic nervous system operates at what level?

subconscious

What is responsible for all sympathetic innervation to the head and neck?

superior cervical ganglion

What stimulates orgasm?

sympathetic

What are the 2 divisions of the autonomic nervous system?

sympathetic parasympathetic

Cardiopulmonary splanchnic nerve

sympathetic innervation of trunk synapse in trunk

Abdominopelvic splanchnich nerve

sympathetic innervation of visceral organs do not synapse in trunk

The adrenal medulla is functionally part of the ...

sympathetic nervous system.

What is the name of the 2 columns of sympathetic ganglia that flank the spine?

sympathetic paravertebral trunk

What nerve carries information to the thorax and abdomen and where does it originate?

the Vagus nerve originates in the brain

What is the periarterial plexus?

the carotid plexus running along the carotid arteries

Post-ganglionic axons from the superior cervical ganglionic piggyback what?

the common internal carotid arteries

In the autonomic nervous system, what is unmyelinated?

the post-ganglionic axon

In the autonomic nervous system, what is myelinated?

the pre-ganglionic axon

The adrenal medulla works with what?

the sympathetic division in stimulate effector organs

Where does the superior cervical ganglion receive communication from?

the upper thoracic levels of the spinal cord

What is another name for the sympathetic division?

thoracolumbar division

What causes Horner's syndrome?

unilateral damage to the cervical sympathetic trunk causes a loss of sympathetic input to some head functions

What parasympathetic cranial nerve is the major nerve for the thorax and abdomen viscera?

vagus nerve (X)

How do sympathetic pre-ganglionic axons exit the spinal cord?

via ventral roots

How do sympathetic pre-ganglionic axons enter the sympathetic trunk?

via white rami communicantes

What does the autonomic nervous system control?

visceral body functions

What kind of neurons are in the lateral horn?

visceral motor

General Visceral Efferent Nerve Fibers

visceral motor axons of preganglionic parasympathetic neurons for smooth muscle and glands

What makes up the autonomic nervous system?

visceral motor involuntary nerves

What are 2 other names for the autonomic nervous system?

visceral nervous system involuntary nervous system

What does referred visceral pain mean?

visceral pain afferents excite somatic neurons at the same spinal level and so can give the impression that the pain is originating from the associated dermatome

General Visceral Afferent Nerve Fibers

visceral sensory convey sensory input from viscera (pain, blood pressure, etc)