Autonomic Nervous System

Question 1

Sympathetic Response

Answer 1

“fight or flight”
Emergency response, exercise, excitement

Question 2

Parasympathetic Response

Answer 2

“Rest and Digest”
Regeneration of tissue, absorption of nutrients, energy diverted to digestive, reproductive, urinary, and immune systems

Question 3

Somatic Function

Answer 3

Consciously controlled

Question 4

Somatosensory Function

Answer 4

Sensory info travels from tissues to the CNS
-Muscles, joints, skin, special senses.

Question 5

Somatamotor Function

Answer 5

Motor information traveling from the CNS to the skeletal muscles
Voluntary control from cerebrum
Involuntary movement and reflexes from brainstem and spinal chord.

Question 6

Autonomic function

Answer 6

Processes which are regulated without conscious intent
Responds to visceral (organ) sensory input
Signals from CNS to heart, smooth muscle, glands
 Maintains homeostasis

Question 7

Hypothalamus

Answer 7

ANS control center
-Sympathetic and parasympathetic responses
-Influenced by frontal cortex and limbic system

Question 8

Brainstem

Answer 8

Controls visceral reflexes
-Blood pressure regulation
-Direction of blood flow
-Cardiac activity

Question 9

Spinal cord

Answer 9

-Controls two important visceral reflexes
-Urination and defecation

Question 10

ANS Ganglia

Answer 10

• Collection of neuronal bodies found in the peripheral nervous system (synapses)

Question 11

Posterior root ganglion

Answer 11

Cell bodies of unipolar sensory neurons

Question 12

Sympathetic/Parasympathetic ganglia

Answer 12

Synapsing of preganglionic and postganglionic neurons

Question 13

Parasympathetic division of the cranial nerves

Answer 13

“Craniosacral division”
-Originates at cranial nerves III, VII, IX, X and sacral nerves 2, 3, 4
-Long preganglionic neurons
-Synapse with short postganglionic fibers
-Ganglions found close to organs

Question 14

Terminal Ganglia

Answer 14

-Parasympathetic ganglia
-Close to organ effector

Question 15

Intramural Ganglia

Answer 15

-Parasympathetic ganglia
-Embedded into organ wall

Question 16

Sympathetic division of cranial nerves

Answer 16

“Thoracolumbar”
-Originates in lateral horn of spinal segment t1 to L2
-Short preganglionic neurons
-Synapses with long postganglionic neurons
-Ganglia found close to spinal column

Question 17

Sympathetic chain ganglia

Answer 17

On either side of the spinal column
Essentially operate as a relay station for the SNS
-Myelinated presynaptic neurons originate in lateral horns of spinal cord
Three options for synapsing:
1. Synapse in ganglion with postsynaptic neuron
2. Axon passes through ganglion and continues as part of splanchnic nerve
3. Axon ascends/descends in chain to synapse at higher or lower levels and continues as part of that spinal nerve

Question 18

White Rami

Answer 18

Myelinated preganglionic sympathetic axons from nerve to ganglion
-“Exit ramp” from nerve; “entrance ramp” to ganglion

Question 19

Gray Rami

Answer 19

Unmyelinated postganglionic sympathetic axons from ganglion to spinal nerve

Question 20

Sympathetic Spinal Nerve Pathway

Answer 20

Preganglionic myelinated axons synapse in ganglion with unmyelinated postganglionic neuron
 Postganglionic axons returns to spinal nerve
* Targets integumentary
structures

Question 21

Postganglionic Sympathetic Nerve Pathway

Answer 21

Myelinated preganglionic axons synapse with unmyelinated postganglionic neurons in ganglion or ascend/descend chain to synapse with postganglionic neuron
* Targets head, neck, thoracic viscera
 Cardiac nerve innervates heart

Question 22

Splanchnic Nerve Pathway

Answer 22

Postganglionic axon passes through ganglion without synapsing
* Continues as part of splanchnic nerve
 Greater splanchnic nerve
 Lesser splanchnic nerve
 Least (lowest) splanchnic nerve
* Targets abdominal and
pelvic viscera

Question 23

Adrenal Medulla Pathway

Answer 23

Preganglionic axon passes through ganglion to lesser splanchnic nerve
* Targets adrenal glands
 Stimulates release of adrenaline from adrenal glands
 Maintains fight or flight response

Question 24

Acetylcholine

Answer 24

 Neurotransmitter of parasympathetic division
 Cholinergic neurons
 All ANS preganglionic neurons
 All parasympathetic postganglionic neurons
 Target cells have cholinergic receptors

Question 25

Norepinephrine

Answer 25

 “Catecholamine”
 Neurotransmitters of sympathetic division
 Adrenergic neurons
 Most sympathetic postganglionic neurons are adrenergic
 Target cells have adrenergic receptors

Question 26

Nicotinic receptors

Answer 26

 Bind acetylcholine
 Found on postganglionic neurons and adrenal medulla cells
 Always excitatory
 Directly opens ion channel
 Sodium moves into cell
 Cell depolarizes
 Faster

Question 27

Muscarinic receptors

Answer 27

 Bind acetylcholine
 Found in all target organs of parasympathetic division
 Excitatory or inhibitory
 Muscarinic receptors use second messengers
 Rather than directly opening channel, a signaling cascade sends message
 Slower

Question 28

Alpha (α) receptors

Answer 28

 Bind norepinephrine
 Stimulated by NE

Question 29

Beta (b) receptors

Answer 29

-bind norepinephrine
-stimulated or inhibited by NE
-b1 = stimulated
-b2 = inhibited
-b3 = either

Question 30

Autonomic Tone

Answer 30

Balance between sympathetic and parasympathetic systems
* Dual innervation
 Most effectors innervated by both ANS divisions simultaneously
 Regulation of activity
 Heart rate
 Blood pressure
 Tone of smooth muscle of digestive tract
 Bronchodilation/ constriction

Question 31

Autonomic Reflexes

Answer 31

“Visceral reflexes”
 Shortest pathway between stimulus and response
 Includes: Receptor>Sensory neuron>CNS integration center>Motor neuron>Effector

Question 32

Cardiovascular reflex

Answer 32

Blood pressure

Question 33

Gastrointestinal reflex

Answer 33

Defecation

Question 34

Micturition reflex

Answer 34

Urination