Autonomic Nervous System Flashcards
1
Q
What does the sensory component of the SNS deal with?
A
Information related to our external environment.
2
Q
What does the sensory component of the ANS deal with?
A
Information related to our internal environment.
3
Q
What type of sensory input do we generally perceive?
A
Somatic sensory input, not autonomic sensory input.
4
Q
Where does the motor component of the SNS transmit signals to?
A
Skeletal muscle.
5
Q
Where does the motor component of the ANS transmit signals to?
A
Cardiac muscle, smooth muscle, and glands.
6
Q
Do we generally have conscious control over somatic motor output?
A
Yes
7
Q
Do we generally have conscious control over autonomic motor output?
A
No
8
Q
How many neurons are involved in the pathway from the central nervous system to the target effector in the SNS?
A
One neuron.
9
Q
How many neurons are involved in the pathway from the central nervous system to the target effector in the ANS?
A
Two neurons.
10
Q
sensory input of the SNS
A
external environment
Somatic sensory receptors (touch, pain)
Special sensory receptors (vision, hearing
11
Q
Sensory input ANS
A
Internal environment
Chemoreceptors (chemicals)
Mechanoreceptors (stretch)
12
Q
perception of sensory input SNS vs ANS
A
SNS, yes - generally
ANS, No - generally
13
Q
motor output SNS vs ANS
A
SNS: skeletal
ANS: Visceral organs
14
Q
Conscious control of motor output: SNS vs ANS
A
SNS: yes (cerebral cortex)
ANS: NO: subcortical areas
15
Q
peripheral motor pathway: SNS VS ANS
A
SNS: 1 neuron
ANS: 2 neurons
16
Q
Where is the cell body of the preganglionic neuron located?
A
In the brain stem or lateral horn of the spinal cord.
17
Q
What type of axon does the preganglionic neuron have and where does it exit the CNS?
A
Myelinated axon. It exits the CNS as part of a cranial nerve or anterior root of a spinal nerve.
18
Q
Where does the preganglionic neuron carry signals to?
A
To a peripheral ganglion.
19
Q
Where is the cell body of the postganglionic neuron located?
A
In a peripheral ganglion.
20
Q
What type of axon does the postganglionic neuron have?
A
Unmyelinated axon.
21
Q
Where does the axon of the postganglionic neuron carry signals to?
A
To an effector.
22
Q
What are the two neurons in the peripheral autonomic motor pathways?
A
Preganglionic neuron and postganglionic neuron.
23
Q
What is a ganglion?
A
A cluster of neuronal cell bodies outside of the central nervous system.
24
Q
Where are the cell bodies of preganglionic neurons located?
A
In the central nervous system.
25
Where do the axons of preganglionic neurons transmit signals to?
Peripheral ganglia.
26
Where are the cell bodies of postganglionic neurons located?
In the peripheral ganglia.
27
Where do the axons of postganglionic neurons transmit signals to?
To the target effectors.
28
Which neurons come before the peripheral ganglia?
Preganglionic neurons.
29
Which neurons come after the peripheral ganglia?
Postganglionic neurons.
30
What is the main difference between the peripheral motor pathways of the SNS and ANS?
The SNS pathways involve skeletal muscle, while the ANS pathways involve cardiac muscle, smooth muscle, and glands.
31
Where are the cell bodies of lower motor neurons located in somatic motor pathways?
In the anterior horn of the spinal cord.
32
Where do the axons of lower motor neurons transmit signals to? (SNS)
To skeletal muscle.
33
Where are the cell bodies of preganglionic neurons located in autonomic motor pathways?
In the lateral horn of the spinal cord or in the brainstem.
34
Where do the axons of preganglionic neurons exit and transmit signals to?
They exit the spinal cord or brainstem and transmit signals to postganglionic neurons with cell bodies in peripheral ganglia.
35
What do the axons of postganglionic neurons transmit signals to?
To cardiac muscle, smooth muscle, and glands.
36
what does the somatic nervous system consist of?
1 neuron
lower motor neuron
37
what does the autonomic nervous system consist of?
2 neurons
pre and post ganglionic
38
How can the ANS be divided?
Into sympathetic and parasympathetic divisions.
39
What tends to be the relationship between the effects of the sympathetic and parasympathetic divisions on visceral organs and tissues?
They tend to have opposing effects.
40
Where do the preganglionic neurons of the sympathetic nervous system originate?
In the lateral horns of the T1 to L2 spinal cord segments.
41
Where do the preganglionic neurons of the parasympathetic nervous system originate?
In the brainstem and lateral horns of the S2 to S4 spinal cord segments
42
“Thoracolumbar outflow”
the output of the sympathetic nervous system.
Preganglionic neurons that originate in the lateral horns of the T1-L2 spinal cord segments
43
Where do the postganglionic neurons of the sympathetic nervous system originate?
In peripheral ganglia.
44
What are the two locations of peripheral ganglia for the sympathetic nervous system?
Sympathetic chain ganglia along the vertebral column, and prevertebral ganglia within the abdominal cavity.
45
Where does the output from sympathetic chain ganglia generally go?
To viscera located above the diaphragm.
46
Where does the output from prevertebral ganglia generally go?
To viscera located below the diaphragm.
47
What are the two types of peripheral ganglia for the sympathetic nervous system?
Sympathetic trunk (chain) ganglia and prevertebral ganglia.
48
Where do sympathetic trunk (chain) ganglia run?
Along either side of the vertebral column.
49
What do sympathetic trunk (chain) ganglia generally innervate?
Viscera above the diaphragm.
50
Where are prevertebral ganglia located?
Close to large arteries in the abdominal cavity.
51
What do prevertebral ganglia generally innervate?
Viscera below the diaphragm.
52
What are the branches of each spinal nerve?
Anterior (ventral) ramus, posterior (dorsal) ramus, and ramus communicantes.
53
What does the anterior (ventral) ramus supply?
Sensory and motor innervation to the anterior and lateral trunk and limbs.
54
What does the posterior (dorsal) ramus supply?
Sensory and motor innervation to the posterior trunk.
55
What is the ramus communicantes associated with?
The autonomic nervous system.
56
What are the interconnected ganglia along the vertebral column called?
Sympathetic trunks or sympathetic chains.
57
Where are myelinated or white ramus communicantes found?
At the T1 to L2 levels of the spine.
58
What do the white ramus communicantes contain?
Axons of preganglionic neurons originating from the lateral horns of the spinal cord.
59
What do pre-ganglionic neurons do when they enter a sympathetic trunk ganglion?
Stop and talk to other neurons there (synapse).
Travel up (towards the head) or down (towards the lower body) the trunk and talk to neurons in another ganglion.
Pass through the ganglion without stopping and continue to another ganglion in the abdominal area (prevertebral ganglion) to talk to neurons there (synapse).
60
where do the postganglionic neurons that originate in the trunk ganglia generally innervate?
viscera above the diaphragm.
61
where do post-ganglionic neurons that originate in the prevertebral ganglia generally innervate?
viscera below the diaphrahm
62
Where are the cell bodies of sympathetic preganglionic neurons located?
The cell bodies of sympathetic preganglionic neurons are located in the lateral horns of the T1 to L2 spinal cord segments.
63
Where are the cell bodies of sympathetic postganglionic neurons located for viscera above the diaphragm?
The cell bodies of sympathetic postganglionic neurons for viscera above the diaphragm are located in the sympathetic trunk ganglia.
64
Where are the cell bodies of sympathetic postganglionic neurons located for viscera below the diaphragm?
The cell bodies of sympathetic postganglionic neurons for viscera below the diaphragm are located in the prevertebral ganglia.
65
Where do preganglionic neurons of the parasympathetic nervous system originate? (2 points)
1. Brainstem
2. Lateral horns of the S2 to S4 spinal cord segments
66
What is the term used to describe the output of the parasympathetic nervous system?
Cranial-sacral outflow
67
Where do postganglionic neurons of the parasympathetic nervous system originate?
Terminal ganglia
Close to their target viscera
68
Where do parasympathetic neurons originating from the brainstem innervate?
Viscera of the head (CNs III, VII, IX)
Thoracic cavity
Most of the abdominal cavity (CN X)
69
Which spinal cord segments are involved in innervating part of the large intestine and pelvic viscera?
Parasympathetic neurons from S2-S4 segments.
70
which cranial nerves autonomic motor functions? (parasympathetic in nature)
Cn III
Cn VII
Cn IX
Cn X
71
where do postganglionic parasympathetic neurons originate?
in “terminal” ganglia that are located close to or within the visceral organs
72
Terminal Ganglia
Clusters of nerve cell bodies located at the end of autonomic nerve fibers within target organs. They play a key role in regulating involuntary bodily functions through the autonomic nervous system's sympathetic and parasympathetic divisions.
73
Craniosacral Outflow
The part of the parasympathetic nervous system that originates from the cranial nerves and the sacral region of the spinal cord. It regulates "rest and digest" functions in the body, such as slowing heart rate and promoting digestion.
74
Where are the cell bodies of preganglionic neurons located in the cranial portion of the parasympathetic nervous system?
Certain brainstem nuclei.
75
Which cranial nerves carry the axons of preganglionic neurons intended for viscera in the head?
Cranial nerves 3, 7, and 9.
76
Which cranial nerve carries the axons of preganglionic neurons intended for viscera in the thoracic and most of the abdominal cavity?
Cranial nerve 10.
77
Where are the cell bodies of postganglionic neurons located in the cranial portion of the parasympathetic nervous system?
Terminal ganglia located close to the target viscera.
78
Where are the cell bodies of preganglionic neurons located in the sacral portion of the parasympathetic nervous system?
In the lateral horns of the S2 to S4 spinal cord segments.
79
How do the axons of preganglionic neurons in the sacral portion reach their target viscera?
Via splanchnic nerves.
80
Where are the cell bodies of postganglionic neurons located in the sacral portion of the parasympathetic nervous system?
In terminal ganglia located close to their target viscera.
81
What are splanchnic nerves?
Splanchnic nerves are nerves that convey autonomic signals, including both sympathetic and parasympathetic fibers, to and from the viscera (internal organs) of the body.
82
Where are the cell bodies of parasympathetic preganglionic neurons located for signals targeting viscera above the pelvic cavity?
In the brainstem, with axons contained within cranial nerves 3, 7, 9, and 10.
83
Where are the cell bodies of parasympathetic preganglionic neurons located for signals targeting viscera within the pelvic cavity?
In the lateral horns of the S2 to S4 spinal cord segments.
84
Where are the cell bodies of all parasympathetic postganglionic neurons located?
In terminal ganglia located close to their target viscera.
85
What is the primary area in the brain that monitors and regulates the balance between the sympathetic and parasympathetic nervous systems?
The hypothalamus.
86
How does the hypothalamus regulate the balance between sympathetic and parasympathetic input to visceral organs?
By adjusting the relative input from these two systems, either tuning down the parasympathetic input, tuning up the sympathetic input, or both.
87
What determines the relative effect of sympathetic and parasympathetic input on organs?
The balance ("tone") between the two systems, regulated by the hypothalamus.
88
when do most organs receive innervation from both the sympathetic and parasympathetic nervous systems?
Continuously
89
What does the term "tone" refer to in the context of the autonomic nervous system?
The balance or relative activity level of the sympathetic and parasympathetic nervous systems, which determines the overall effect on organs.
90
How are the effects of the sympathetic nervous system typically described?
As "fight or flight," as they tend to increase during stressful situations.
91
How are the effects of the parasympathetic nervous system typically described?
As "rest and digest," as they tend to increase during times of relaxation and recovery.
92
skin sympathetic and parasympathetic response:
symp: increased sweat production, contraction of arrector pili muscles
para: none
93
Eyes sympathetic and parasympathetic response:
symp: pupil dialation, distant vision
para: pupil constriction, near vision
94
skeletal muscle sympathetic and parasympathetic response:
symp: vasodilation
para: none
95
heart symp and para:
symp: increased heart rate and force of contraction, Increased blood pressure
para: Decreased heart rate & force of contraction
Decreased blood pressure
96
Lungs symp and para:
symp: Airway dilation
para: Airway constriction
97
Digestive system symp and para:
symp: Decreased motility & gland secretion
Sphincter contraction
para:Increased motility & gland secretion
Sphincter relaxation
98
Liver
symp: Glycogen breakdown & release of glucose
para: Glycogen synthesis
99
Adipose tissue
symp: Breakdown of fats & release of fatty acids
para: none
100
Urinary system
symp: Bladder relaxation; sphincter contraction
Vasoconstriction (decreased urine)
para: Bladder contraction; sphincter relaxation
101
Reproductive system
symp: ejaculation
para: erection
