Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ANAT 316 Term 1 > Lecture 6 - The Autonomic Nervous System > Flashcards

Lecture 6 - The Autonomic Nervous System Flashcards

1
Q

What kind of movements does the autonomic nervous system control? include examples

A
  • involuntary motor (effernt)/unconscious processes
  • innervates smooth & cardiac muscle, viscera, and glands
  • ex: heart rate, respiration, blood pressure, sweating, digestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the main goal of the ANS?

A

maintain homeostasis throuhgout the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three systems thats branch off of the ANS?

A
  • sympathetic
  • parasympathetic
  • enteric
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the sympathetic nervous system (SNS)?

A
  • stimulates metabolism; most active during times of exertion, stress, or emergency
  • “fight or flight”
  • ex: increase heart rate, force of contration and blood pressure & pauses digestion & dilates blood vessels in skeletal muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the parasympathetic nervous system (PSNS)?

A
  • promotes relaxation, nutrient uptake, energy storage; most active under resting conditions
  • “rest and digest”
  • ex: decrease heart rate, force of contration and blood pressure & stimulates digestion, dilates blood vessels in GI tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

SNS vs PSNS

A
  • most organs receive both sympathetic and parasympathetic innervation
  • they are functionally and anatomically distinct
  • effects are generally opposing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a neruon and what is their anatomy?

A
  • basic functional unit of the nervous system; highly specialized cells that carry electric signals
  • neuronal cell body
    -> axon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What surrounds the axon of nerve cells and what does it do?

A
  • Myelin sheath (lipid-rich sheath)
  • acts as an insulating layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Efferent: Somatic vs Autonomic

A

Somatic:
- motor neuron (ventral horn)
- voluntary control
- one neuron between CNS and target
- 1 nerve fiber
- innervates skeletal muscle
Autonomic:
- visceral motor neuron (spinal cord; or brainstem nuclei)
- involuntary control
- two neurons between CNS and target
- preganglionic neuron -> autonomic ganglion -> postganglionic neuron
- innervates cardiac muscle, smooth muscle, glands, viscera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Location of neuronal cell bodies of pregranglionic vs postganglionic neuron

A
  • pre: brainstem or spinal cord
  • post: autonomic ganglion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Is the preganglionic neuron myelinated?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is the postganglionic neuron myelinated?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a ganglion? and what is the DRG?

A
  • collection of neuronal cell bodies found in the PNS
  • DRG: sensory (afferent) ganglion of the somatic nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the ganglion function as?

A

a relay station between preganglionic and postganglionic neurons of the ANS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the regions of the SNS?

A
  • “thoraco-lumbar”
  • T1-L2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the regions of the PSNS?

A
  • “cranio-sacral”
  • cranial nerves:
    • CNIII:
      Occulomotor
    • CNVII: Facial
    • CN IX:
      Glossopharyngeal
    • CNX: Vagus
  • sacrial regions: S2-S4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the three types of prevertebral ganglia?

A
  • celiac
  • superior mesentreric
  • inferior mesenteric
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the sympathetic chain?

A
  • sympathetic ganglia
  • aka sumpathetic trunk or paraverterbral ganglia
  • paired sympathetic ganglia linked together to form a chain along the length of the vertebral colum (C1-S5)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why are the ganglia connected to each other in the sympathetic chain?

A

it coordinates and spreads ympathetic responses to many target tissues simultaneously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the prevertebral ganglia?

A
  • situated anterior to the vertebral column, along the aorta
  • named relative to blood vessels branching from the abdomincal aorta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where are sympathetic ganglia located?

A

close to the vertebral colum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Is preganglionic ganglia long or short? Postganglionic

A
  • pre: short
  • post: long
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are Rami communicans?

A
  • connectin between the spinal nerve and sympathetci trunk
24
Q

What are the two types of communicantes?

A
  • white and gray ramus communicans
25
Q

Where are white rami? Grey?

A
  • white: T1-L2
  • grey: at all levels along the sympathetic chain
26
Q

Where does sympathetic outflow originate?

A

in the lateral horn of the spinal cord, from segments T1-L2

27
Q

Where do preganglionic (myelinated) neurons exit the spinal cord?

A
  • via the ventral horn and root to enter the spinal nerve
28
Q

Where do preganglionic neurons enter the sympathetic chain?

A
  • via the white ramus communicans “on ramp”
29
Q

What are the 3 main roots of preganglionic neurons upon entering the sympathetic chain?

A
  1. synapse within the chain at the same level
  2. change level within the chain and then synapse
  3. formation of the splanchnic nerve
30
Q

Synapse within the chain at the same level

A
  • preganglionic neuron synapses with postganglionic neuron at the same level & exits via the grey ramus, travelling with spinal nerve to target
  • ex: sympathetic innervation of blood vessels & sweat glabdss of the body wall & limbs
31
Q

Same level

A

preganglionic neurons located between T1-L2

32
Q

Nerve target

A
  • body wall
  • abdominal and thoracic viscera
  • limbs
33
Q

What is a dermatomes?

A

strip of skin supplied by a spinal nerve

34
Q

preganglionic neuron

A
  • located in the lateral horn (T1-L2)
  • myelinated preganglionic axon exits spinal cord via the ventral horn and ventral root to enter the spinal nerve
  • preganglionic axon then leaves spinal nerve, and enters the sympathetic trunk via white ramus communicans (white communicating ramus) to synapse on the postganglionic neuron
    • communicating ramus is called ‘white’ because the preganglionic fibers it carries are myelinated
35
Q

postganglionic neuron

A
  • unmyelinated postganglionic axon passes through the gray ramus communicans to enter the spinal nerve
    • communicating ramus is ‘gray’ because the postganglionic fibers it carries are unmyelinated
  • postganglionic fiber travels within spinal nerve to innervate target
36
Q

Change level: preganglionic fiber can ascend or descend within the sympathetic chain

A
  • sympathetic distribution is from T1-L2
  • preganglionic nerve fibers can ascend or descend above/below/within this distribution before synapsing
37
Q

ascending nerves target… (3)

A
  • head and neck viscera
  • thoracic viscera
  • upper limbs
38
Q

descending nerves target… (2)

A
  • abdomino pelvic viscera
  • lower limbs
39
Q

viscera of the thorax

A
  • orgasn in the thorax are supplied to various plexuses
  • postganglionic contribute to autonomic plexuses including cardiac plexus (heart), pulmonary plexus (lungs)
40
Q

splanchnic nerves aka visceral nerves

A
  • typically associated with abdominopelvic viscera
41
Q

When do splanchnic nerve form?

A

when autonomic fibers do not re-join the spinal nerve; instead fibers form splanchnic nerve

42
Q

where do preganglionic fibers bypasses the sympathetic chain completely and synapses in?

A

A peripheral (prevertebral) ganglion near the target organ

43
Q

Abdominopelvic viscera

A
  • ## preganglionic nerve fibers pass through sympathetic trunk without synapsing and form splanchnic nerves
44
Q

originate from thoracic and lumbar vertebral levels of the spinal cord, as sets of paired splanchnic nerves, including:

A
  • greater splanchnic
  • lesser splanchnic
  • least/lumbar splanchnic
45
Q

sympathetic splanchnic nerves synapse in prevertebral ganglia:

A
  • celiac ganglion
  • superior mesentric ganglion
  • inferior mesenteric ganglion
46
Q

throacic & lumbar splanchnic nerves:

A
  • greater (T5-9)
  • lesser (T10-11)
  • least/lumbar (T12-L2)
47
Q

synapse in prevertebral ganglia

A
  • celiac
  • superior mesenteric
  • inferior mesenteric
48
Q

Cranial Outflow: Head & Neck

A
  • CN III, VII , IX
  • preganglionic neurons leave brainstem from parasympathetic nuclei
  • synapse on post-ganglionic neuron within parasympathetic ganglia
49
Q
A
  • preganglionic neurons leave the brainstem via CN X (vagus nerve) which contributes to autonomic plexuses
  • supplied parasympathetics to pharynx, larynx, thorax & midgut structures (to transverse colon)
  • preganglionic neurons synapse on ganglia within or close to target oragn
50
Q
A
  • preganglionic neuronal cell bodies located in spinal segments S2-S4
    • axons travel via pelvic splanchnic nerves which contribute to autonomic plexuses
  • preganglionic fibers synapse within ganglia in or near effector organ to supply targets
51
Q
A

visceral afferent fibers conduct sensory information from autonomic targets to the CNS (ex: organs)

52
Q
A

visceral affeent fibers are distinct from the autonomic nervous system (visceral motor) and are not considered sympathetic or parasympathetic

53
Q

afferent fibers

A

carry sensory information to the CNS

54
Q

visceral reflexes

A

are the simplest functional units in the autonomic nervous system

55
Q

visceral afferent fibers and visceral reflexes

A
  • visceral reflex arcs consist of a sensory nerve (visceral afferent), and visceral motor neurons
  • ex: shinning a light in the eye triggers a visceral reflex that constricts the pupils
56
Q

enteric nervous system

A
  • the ANS includes a third divison called the enteric nervous system
    • network of neurons located in the wlls of the digestive tract
57
Q
A

enteric nervous system receives regulatory signals via sympathetic and parasympathetic divisions
- however, many complex visceral reflexes are initiated and coordinated independently of sympathetic and parasympathetic NS

ANAT 316 Term 1 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions