Brainscape's Knowledge GenomeTM

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


See full index

functional neuroanatomy > Week 3 - PNS > Flashcards

Week 3 - PNS Flashcards

1
Q

What does the CNS consist of?

A

brain and spinal cord

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

What is the function of the CNS ?

A

Integration and analysis of information, production of responses

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

What does the PNS consist of?

A

outside the CNS comprising nerves and ganglia

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

What is the function of the PNS ?

A

reception of information and transmission of response (including homeostatic regulation)

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

What is the PNS made up of?

A

sensory and motor components

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

What are the sensory components of the PNS?

A
  • somatic and visceral sensory: sensory ganglia anf nerves, receptors
  • special sensory eg. retina -eye
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the motor components of the PNS?

A
  • somatic motor: motor nerves
  • visceral motor (autonomic): sympathetic/parasympathetic/enteric divisions, autonomic ganglia and nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where do some motor components such as motor neuron cell bodies originate from?

A

brainstem and spinal cord

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

Where are the axons of the motor neurons (efferent) going to skeletal muscle found?

A

PNS

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

How do motor components enter and leave the spinal cord?

A
  • motor (efferent) axons exit in ventral root
  • sensory (afferent) axons enter in dorsal root
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where do motor (efferent) neurons have their cell bodies?

A

in the grey matter in the ventral spinal cord

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

Where are sensory neuron cell bodies located?

A

in the dorsal root ganglion - peripheral
- sent info into spinal cord via ganglion

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

What is the spinal cord?

A

the major origin of the PNS

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

How is the spinal cord protected?

A

cushioned by a layer of fat inside the vertebral canal, contained in meninges

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

What is the rout of nerve roots int he spine?

A

emerge from cord leaving the spine through intervertebral foramina

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

Ventral root contains

A

motory output

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

Dorsal root contains

A

sensory input

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

What are spinal nerves?

A

nerver roots fused together

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

Is the intervertebral foramen resistant to damage?

A

no, damaged easily - may lead to motor loss, sensory alterations

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

How many pairs of spinal nerves are there?

A

31 pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do spinal nerves do?

A
  • arise from spinal cord roots
  • supply all parts of the body except the head
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How are spinal nerves named?

A

according to their point of issue between vertebrae

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

Name all spinal nerves:

A
  • 8 cervical (C1-C8)
  • 12 thoracid (T1-T12)
  • 5 lumbar (L1-L5)
  • 5 sacral (S1-S5)
  • 1 coccygeal (C0)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What arises from spinal nerves?

A

peripheral nerves - mixed motor and sensory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What peripheral nerve is in the trunk ?

A

single major intercostal nerve - from a single spinal level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What peripheral nerve is in the neck and limbs?

A

multiple spinal levels contribute to 4 plexi and multiple nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

name all 4 flexi from top to bottom

A
  • celvical plexus
  • brachial plexus
  • lumbar plexus
  • sacral plexus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the difference between spinal and peripheral nerves?

A

Intercostal nerve comes from ventral ramus of spinal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does the spinal nerve divide into?

A

dorsal ramus and ventral ramus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What area is supplied by the dorsal ramus?

A

skin and muscles of the back

31
Q

What area is supplied by the ventral ramus?

A

skin and muscles of chest abdomen and limbs

32
Q

How do ventral rami supply the limbs?

A

via an interwoven network of nerve fibres - a nerve plexus

33
Q

What are ramus communicans ?

A

further branches of the spinal nerves at spinal levels T1-L3

34
Q

Where do ramus communicans connect to?

A

sympathetic chain - series of linked sympathetic ganglia, lying on either side of the vertebral column

35
Q

What is a dermatome?

A

a strip of skin innervated by sensory axons of a single dorsal nerve root (or spinal nerve)

36
Q

Do peripheral nerves match the territory of dermatomes?

A

no it doesn’t, as they have contributions form more than one dorsal root

37
Q

What are nerve coverings made up of?

A

epineurium
perineurium
endoneurium

38
Q

What is the epineurium?

A
  • continuation of dura mater of the CNS
  • provides mechanical strength for a nerve
39
Q

What are fascicles?

A

axons in a nerve grouped into bundles

40
Q

What is the perineurium?

A

continuation of arachnoid mater that surrounds fascicles
- cells have tight junctions
- form barrier between nerve and external environment

41
Q

What is the endoneurium?

A
  • continuous with Pia meta
  • comprises vascular connective tissue surrounding the axons and their Schwann cells
42
Q

What are Schwann cells?

A
  • supportive glial cells in nerves
  • vital for Acton function: maintain the environment ie. pH, glucose at correct levels
43
Q

Do all nerve fibres need Schwann cells?

A

Yes

44
Q

What do single myelinated fibres have?

A

a personal set of Schwann cells that wrap themselves around the axon supporting and forming myelin

45
Q

How many unmyelinated cells can a single Schwann cell support?

A

up to 20

46
Q

What difference is there in peripheral nerve fibres (axons)?

A

different sizes and different functions

47
Q

What is the advantage of larger diameter fibres?

A
  • have more myelin
  • conduct action potentials more rapidly
48
Q

What fibres have the slowest conducting?

A

unmyelinated C-fibres

49
Q

What will later axons be?

A

motor neurones - to be quick, allowing for rapid movement

50
Q

Name peripheral nerve fibres from large to smallest

A

lower motor neurone - alpha
Touch receptors
delta fibres - sharp pain, cold, preganglionic autonomic
C fibres - unmyelinated, slowest. slow pain, heat, itch, postganglionic autonomic

51
Q

Somatosensory - muscle stretch reflex

A

contraction of extension muscle - kick
opposing muscle (flexor) must be inhibited - inhibitory interneuron
- receptor sensing stretch at terminals of sensory neuron in sensory root of ganglion
- in via dorsal root into spinal cord

52
Q

What is signal transduction?

A

process of converting the energy of a stimulus into an electrical signal

53
Q

How is single transduction achieved?

A
  • in somatosensory afferent endings
  • through the opening of cation channels
  • producing depolarising receptor or generator potential
  • sufficient magnitude: reaches threshold necessary for action potential firing by afferent
  • rate of firing roughly proportional to magnitude of depolarisation
54
Q

Do sensory nerve fibres have different endings?

A

Yes

55
Q

What are most mechanoreceptive endings (AAlpha, Abeta) like?

A
  • encapsulated by receptor cells and structures that help tune the afferent to particular features of stimulus
56
Q

What are free nerve endings?

A
  • lack specialised cells
  • eg. Agamma, C fibres
57
Q

How do free nerve endings transduce the signal?

A
  • through receptor linked ion channels within their plasma membranes
  • detect chemical changes in environment eg. pH or physical stimuli eg. heat, movement
58
Q

What are afferents that detect chemical changes in environment eg. pH or physical stimuli eg. heat, movement?

A
  • nociceptors - detecting injury of painful stimuli
  • thermoreceptors
  • some might be mechanoreceptors
59
Q

Name all encapsulated endings of mechanoreceptors in skin

A
  • Meissner’s afferents
  • Merkel cell afferents
  • Fuddini afferents
  • Pacinian afferents
60
Q

What are Meissner’s afferents?

A

detect skin motion, grip control

61
Q

What do Merkel cell afferents do?

A
  • detect eges, points, curvature
  • form and texture perception
62
Q

What do Ruffini afferents do?

A
  • detect skin stretch
  • tangential force, hand shape and motion direction
63
Q

What do Pacinian afferents do?

A
  • detect vibration
  • perception of stint events through transmitted vibrations
  • tool use
64
Q

What is a receptive field?

A

the area of skin innervated by a single sensory afferent

65
Q

Are there more densely innervated or less innervated areas in the body?

A

more less enervated - eg. forearm back, instead go densely innervated such as fingers and face

66
Q

Does loss of one afferent produce an anaesthetic area?

A

no, because there is overlap

67
Q

What is the 2 point discrimination threshold test ?

A
  • measures min inter-stimulus distance required to perceive 2 simultaneous stimuli as distinct
  • reflects somatic spatial acuity and receptor density
  • areas where the most accurate sensory discrimination is needed have the lowest threshold eg, fingers, hand , face, lips
68
Q

How is visceral sensory information conveyed to the CNS?

A
  • dorsal root ganglia send visceral afferents through sympathetic nerves
  • include mechanoreceptor specialisations or free endings sensitive to pressure or stretch, mechanical and harmful endings
69
Q

What are sensory ganglia’s associated with?

A
  • parasympathetic ns
  • eg. ganglia of C11,10
  • convey general visceral sensory input to CNS to coordinate visceral motor activity
70
Q

What are proprioceptors?

A
  • muscles, tendon, joined mechanoreceptors
71
Q

What do proprioceptors and skin mechanoreceptors provide?

A

detailed, continuous information about the position of our limbs and other parts in space

72
Q

What do proprioceptors do?

A
  • encode information relating to stretch and tension of muscles
  • sensation of position, movement and force
  • essential for accurate performance of complex tasks
73
Q

What are neuromuscular junctions?

A

synaptic connection between motor neuron and skeletal muscle fibre

74
Q

MOTOR EFFERENT

A

functional neuroanatomy (16 decks)

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