Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Neuroscience and Mental health > 10. Peripheral nervous system > Flashcards

10. Peripheral nervous system Flashcards

1
Q

What does the neural component of the ectoderm give rise to?

A

CNS

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

Where are neural crest cells located and what is their function?

A

Located in neural fold (At the junction between non-neural and neural ectoderm)
Function: Relay info. between skin and CNS

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

What does the non-neural component of then ectoderm give rise to?

A

Skin

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

List 3 types neurone fibres

A

A fibres: Myelinated Somatic (associated with skeletal muscles)
B fibres: Myelinated Visceral (associated with internal organs)
C fibres: Unmyelinated Somatic and Visceral pain afferents

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

What does the autonomic nervous system control?

A

Involuntary responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the arrangement of autonomic motor neurons.

A

Autonomic motor neurons have a preganglionic neuron and a postganglionic neuron with an autonomic ganglion in the middle.
Location of the autonomic ganglion varies depending on whether it is sympathetic (spinal cord) or parasympathetic (brain stem nuclei or sacral region)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where do sensory neurons have their cell bodies?

A

In the dorsal root ganglion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which vertebrae do sympathetic nerves arise from?

A

T1 to L2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why do we refer to vagal and sacral nerves as presynaptic or postsynaptic?

A

There are no ganglia associated with vagal or sacral nerves

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

Where do pre-synaptic parasympathetic sacral neurones arise from?

A

S2 to S4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe common developmental features of Pre-ganglionic sympathetic motor neurones (T1 – L2)
and Pre-synaptic parasympathetic Sacral neurons (S2-4).

A

Arise from basal plate of spinal cord
Multipolar
Myelinated
B fibres

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

Describe common developmental features of Post-ganglionic autonomic (symp. and parasymp.) neurones
and post-synaptic parasympathetic neurons

A

Arise from neural crest cells
Multipolar
Unmyelinated
C fibres

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

How do autonomic motor ganglia differ to ganglia of sensory neurones?

A

Autonomic motor ganglia contain synapses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the difference in myelination of A and C fibres

A

A fibre: 1 axon, many layers of myelin

C fibres: Many axons associated with 1 Schwaan cell

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

What do rootlets come together to form?

A

Roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe parasympathetic ganglia

A

Located in CRANIAL part of head

Synapases between pre-ganglionic and post-ganglionic fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 4 parasympathetic ganglia?

A

Ciliary
Submandibular
Otic
Pterygopalatine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 2 divisions of the peripheral nervous system?

A

Autonomic: Motor, sensory and enteric
Somatic: Motor and sensory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How many and what types of nerves are in the peripheral nervous system?

A

43 pairs:
12 Cranial
31 Spinal

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

Describe the distribution of spinal nerves in the peripheral nervous system

A 
8 cervical 
12 thoracic
5 lumbar
5 sacral
1 coccygeal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where do all except C1-C7 of the spinal peripheral nerves arise from?

A

Arise from below corresponding vertebra

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

Generally, peripheral nerves have… function

A

Have mixed motor and sensory function

aside from some cranial nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe transmission in somatic motor nerves

A

Primary motor cortex to brainstem/spinal cord to NMJ (skeletal muscle)
Always stimulatory, don’t fire at rest
Use ACh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe transmission in autonomic motor nerves

A

Hypothalamus to brainstem/spinal cord to ganglion to effector organ
Stimulatory or inhibitory, baseline firing rate
ACh or NA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Describe transmission in somatic and autonomic sensory nerves
Periphery to dorsal root ganglion to brainstem/spinal cord
26
What does somatic and autonomic sensory innervation give?
Sensory info from conscious (somatic) and visceral (autonomic) areas
27
What is found in the ventral root?
Somatic and autonomic motor neurones | Efferent nerves
28
What is found in the dorsal root?
Somatic and autonomic sensory neurones Afferent nerves Cell bodies in dorsal root ganglion (collection of cell bodies)
29
What is found in a spinal nerve?
Motor and sensory neurones of that spinal segment
30
What is found in a dorsal ramus?
Motor and sensory innervating the skin of the back and deep back muscles
31
What is found in a ventral ramus?
Motor and sensory innervating the rest of the body from the neck down
32
What is found in the ventral horn of grey matter?
Somatic motor neurones | Efferent nerves
33
What is found in the dorsal horn of grey matter?
Somatic and autonomic sensory neurones
34
What do all sensory neurones of the PNS arise from?
Neural crest cells
35
Which roots do motor and sensory nerves go out of?
``` Motor = ventral Sensory = dorsal ```
36
Describe peripheral nerve structure
Nerve surrounded by epineurium Bundle of neurones (fascicle) surrounded by perineurium Neurone/axon surrounded by endoneurium
37
What produces myelin in the peripheral nervous system?
Schwann cells
38
What affects propagation speed of a nerve impulse?
Size: Larger fibres conduct impulses faster as less resistance Myelination: Myelinated = faster due to saltatory conduction Temperature: Increased temperature = faster
39
Describe A fibres
``` Largest (5-20 microns) Fastest conduction (130 m/s) Myelinated Somatic Sensory and motor to skeletal muscle Sub-divided into alpha, beta, delta and gamma ```
40
Describe B fibres
Medium (2-3 microns) Medium conduction (15 m/s) Myelinated Visceral Sensory and autonomic preganglionic
41
Describe C fibres
Smallest (0.5-1.5 microns) Slowest conduction (2 m/s) Unmyelinated somatic and visceral pain afferents
42
Nerve plexus
Network of successive ventral rami that exchange fibres (e.g cervical, brachial plexus)
43
Dermatomes
Area of skin supplied by a single sensory nerve root (can determine site of spinal damage)
44
Myotomes
Groups of muscles supplied by a single spinal nerve root (part of neurological exam)
45
Ramus
Motor and sensory nerves together that exit from the roots
46
What are the 2 classifications of distributions of sensory innervation?
Dermatomal Innervation: The strip of skin supplied by a pair of spinal nerves is referred to as a dermatome Peripheral Innervation: The area of skin supplied by a single peripheral nerve
47
What does the brachial plexus innervate? Which ventral rami does it consist of?
Brachial plexus innervates the upper limb. | Consists of ventral rami of C5-T1
48
What does the lumbosacral plexus innervate? Which ventral rami does it consist of?
Lumbosacral plexus innervates lower limbs. | Consists of ventral rami of L1-S3
49
Causes of neuropathies
Many causes e.g. metabolic, inflammatory, genetic | 30% idiopathic
50
Mononeuropathy
Single nerve affected
51
Polyneuropathy
Several nerves affected
52
What does damage to a sensory nerve cause?
Tingling Pain Numbness
53
What does damage to a motor nerve cause?
Weakness to hands and feet
54
What does damage to autonomic nerves cause?
Change in HR | Change in BP
55
How do damaged peripheral nerves differ to those in the CNS?
Axon regeneration can occur in damaged peripheral nerves
56
Describe neuropraxia
``` Compression in axon Reversible conduction block Selective demyelination Axon, Epi-,Peri- and Endoneurium still intact e.g. nerve compression ```
57
Describe Axontomesis
``` Disruption of axon and degeneration of fibre Demyelination. Axon loss. Nerve regrowth possible. Epi- and Perineurium intact ```
58
Describe Neurotmesis
``` Complete nerve division and disruption Disruption to epi-, peri- and endoneurium Damage to epineurium- no nerve growth Axon loss. Common after toxic or ischaemic injury ```
59
Rank peripheral neuropathies from mild to severe
Neuropraxia Axontomesis Neurotmesis
60
List 3 diagnostic techniques for peripheral neuropathies
Electromyography (EMG) Nerve conduction velocity (NCV) Somatosensory evoked potential (SEP)
61
Describe an EMG
Records electrical activity produced by muscles Intramuscular or surface EMG Distinguish muscle disorders vs nerve disorders
62
Describe an NCV
Electrodes stimulate nerves to determine conduction speed Slow speed indicates nerve damage E.g trauma, diabetic/peripheral neuropathy, viral infection, nerve entrapment (Infants <3yrs have low NCV)
63
Describe a somatosensory evoked potential
Electrodes stimulate sensory neurones to determine transmission of sensory info from mechanoreceptors to CNS Often used in multiple sclerosis
64
What is the basal plate?
Basal plate develops into the ventral horn | It is where the motor neurones come from
65
What is the Alar plate?
Alar plate develops into the dorsal horn | It is where the sensory neurones go to
66
2 types of sympathetic ganglia
Paravertebral | Collateral

Neuroscience and Mental health (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions