Topic 9: Nerve Supply of the Lower Limb Flashcards

1
Q

The Nervous System

A
  • Bodies control centre+ communication network
  • Senses changes, interprets changes and responds to changes
  • Highly specialised cells (neurons) that are designed to transmit information around the body
    o Sensory neurons transmit information about conditions inside and outside the body
    o Motor neurons transmit information that controls the activity of muscles and glands
  • Glial/ support cells  provide protection and nutrition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The Central Nervous System

A
  1. Brain and co-located structures
  2. Spinal cord
    All protected by bones of the axial skeleton
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The Peripheral Nervous System (PNS)

A
  • Nerves that connect the CNS to the peripheral structures e.g. skin, muscle, glands
  • cranial nerves
  • spinal nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cranial Nerves

A

o Nerves that emerge directly from the brain/ brainstem
o 12 pairs, named and numbered
o Supply the musculoskeletal structures of the head and neck
o Supply the viscera of the thorax and abdomen

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

Spinal Nerves

A

o Nerves that emerge from the spinal cord
o 31 pairs, each numbered according to the place where it emerges from the spinal cord and vertebral column
 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
o Supply the structures of the trunk wall + limbs
- E.g. spinal nerve

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

Spinal Nerve Formation

A
  1. Spinal cord- cut in cross section, part of the CNS
  2. Sensory Neurons enter at the back of SC
  3. The spinal nerve then divides into a dorsal (posterior) ramus, and a ventral (anterior) ramus
  4. motor and sensory neurons = grouped together in the spinal nerve
  5. motor neurons leave from the front of SC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ventral Ramus

A
  • distributed to the muscles of the anterior + lateral trunk, and the corresponding skin
  • also distributed into the limbs to supply the muscles and skin there
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Dorsal Ramus

A

Distributed to the muscles of the back, and the skin covering those muscles

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

Sensory Distribution

A
  • To skin – sensation e.g. hot, cold, pain, touch, pressure
  • To joints – sensation of joint position (proprioception)
    o General rule for supply of joints – ‘where a nerve supplies a muscle that moves a particular joint, that nerve will also supply that joint’.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Motor Distribution

A

To muscles:
- turns the muscle on, makes it contract (might be concentric, isometric, or eccentric dependent on task requirements)
To glands:
- (usually) increases secretion from gland
- e.g. supply to sweat glands produces sweating

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

Sensory Pathways

A
  1. Touch hot object (pain receptors in skin) –> impulse travels down arm–> dendrite of afferent neuron –> axon of afferent neuron –> cell body of interneuron - spinal cord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Motor Pathways

A

Sensory impulse has been processed by CNS–> cell body of efferent neuron –> axon of efferent neuron –> muscle contracts and withdraws part being stimulated

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

Ventral Rami form plexi

Cervical Plexus

A

C1234, supplies structures in the neck and the diaphragm

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

Brachial Plexus

A

C5678, T1

Supplies the upper limbs

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

Lumbar Plexus

A

L1234

Supplies the lower limb

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

Lumbosacral plexus

A

L45, S123

Supplies the lower limb

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

Lumbar Plexus nerve inclusions

A

Genitofemoral, lateral femoral cutaneous, femoral, obturator

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

Lumbosacral Plexus nerve inclusions

A

Lumbosacral trunk, posterior femoral cutaneous, sciatic

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

Femoral Nerve Root Value

A

L234

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

Femoral Nerve motor distribution

A

iliacus, pectineus, sartorius, quad group

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

Femoral Nerve sensory distribution

A
  1. Skin of anterior and medial thigh

2. knee and hip joints

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

Saphenous nerve (cutaneous branch of femoral) root value

A

none as it branches off the femoral nerve

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

Obturator Nerve Root value

A

L234

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

Saphenous nerve (branch of femoral) motor distribution

A

none

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

Saphenous nerve (branch of femoral) sensory distribution

A

Skin of the medial knee+ leg to base of great toe

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

Obturator Nerve Motor Distribution

A

Pectineus, add brev, add long, 1/2 of add mag, obt ext, gracilis

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

Root value definition

A

where the nerve originates in the SC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Obturator Nerve Sensory Distribution

A

Skin of medial thigh

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

Lateral Femoral Cutaneous nerve root value

A

none (why?)

Is it because it comes off the fem vein?

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

Lateral Femoral Cutaneous nerve motor distribution

A

none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Lateral Femoral Cutaneous nerve sensory distribution

A

skin of the lateral thigh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Genitofemoral nerve root value

A

none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Genitofemoral Nerve motor distribution

A

none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

genitofemoral nerve sensory distribution

A

skin of the medial thigh, skin of the external genitalia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Muscular branches nerve motor distribution

A

iliacus & psoas major

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

LUMBOSACRAL PLEXUS

Posterior Femoral Cutaneous nerve root value

A

XXX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Posterior Femoral Cutaneous nerve motor distribution

A

none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Posterior Femoral Cutaneous nerve sensory distribution

A

skin of posterior thigh and leg to mid calf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Superior gluteal nerve root value

A

XXX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Superior gluteal nerve motor distribution

A

gluteus Medius and minimus, TFL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Superior gluteal nerve sensory distribution

A

hip joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Inferior gluteal nerve root value

A

XXX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Inferior gluteal nerve motor distribution

A

gluteus maximus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Inferior gluteal nerve sensory distribution

A

none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Muscular branches nerve root value

A

XXX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Muscular branches nerve motor distribution

A

external rotators except obt ext

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Muscular branches nerve sensory distribution

A

none

48
Q

Sciatic nerve root value

A

L45S123

49
Q

Sciatic nerve motor distribution

A

hamstrings and hamstring (extensor) half of adductor magnus

50
Q

Sciatic nerve sensory distribution

A

none

51
Q

BRANCHES OF THE SCIATIC NERVE

Tibial Nerve Motor distribution

A

gastrocs, soleus, plantaris, popliteus. TP, FHL, FDL

52
Q

BRANCHES OF THE SCIATIC NERVE

Tibial Nerve Sensory distribution

A

knee and ankle joints

53
Q

BRANCHES OF THE SCIATIC NERVE (branch of tibial)

Medial Plantar Nerve Motor distribution

A

AbdHall, FDB, FHB, 1st lumbrical

54
Q

BRANCHES OF THE SCIATIC NERVE (branch of tibial)

Medial Plantar Nerve Sensory distribution

A

skin of the medial 3 and 1/2 digits and corresponding sole

55
Q

BRANCHES OF THE SCIATIC NERVE (branch of tibial)

Lateral Plantar Nerve Motor distribution

A

FDMB, AddHall, 2nd to 4th lumbricals, intertossei, AbDM, FA

56
Q

BRANCHES OF THE SCIATIC NERVE (branch of tibial)

Lateral Plantar Nerve Sensory distribution

A

skin of the lateral 1 and 1/2 digits and corresponding sole

57
Q

BRANCHES OF THE SCIATIC NERVE (branch of tibial)

Sural Nerve Motor distribution

A

none

58
Q

BRANCHES OF THE SCIATIC NERVE (branch of tibial)

Sural Nerve Sensory distribution

A

skin of the lateral and posterior leg, heel, and skin of the lateral side of the sole

59
Q

Common peroneal nerve motor distribution

A

none directly but see branches

60
Q

BRANCH OF COMMON PERONEAL

Superficial Peroneal motor distribution

A

peroneus longus and brevis

61
Q

BRANCH OF COMMON PERONEAL

Superficial Peroneal sensory distribution

A

skin of lateral leg, dorsum of foot except skin between digits 1 and 2

62
Q

BRANCH OF COMMON PERONEAL

Deep Peroneal motor distribution

A

TA, EHL, EDL, PT, EDB (anterior)

63
Q

BRANCH OF COMMON PERONEAL

Deep Peroneal sensory distribution

A

skin between digits 1 and 2

64
Q

BRANCH OF COMMON PERONEAL

Sural nerve* motor distribution

A

none

65
Q

BRANCH OF COMMON PERONEAL

Sural nerve* sensory distribution

A

skin of the lateral and posterior leg, heel and skin of the lateral side of the sole

66
Q

Hilton’s Law

A

a single nerve can supply the skin, joint, and muscles of that region. e.g. femoral nerve supplies the anterior thigh

67
Q

Innervation of hip joint

A

Innervated primarily by the sciatic, femoral, obturator nerves, and superior gluteal nerve

68
Q

Innervation of knee joint

A

Branches of the femoral nerve to vastus medialis, and also intermedius and lateralis. From the sciatic nerve by genicular branches of the tibial and common peroneal nerves

69
Q

Innervation of ankle joint

A

receives its nerve supply from deep peroneal, saphenous, sural and tibial nerves, occasionally the superficial peroneal nerve also supplies the ankle joint.

70
Q

Most Vulnerable Sites

A
  1. close to skin - penetrating injury e.g. common peroneal nerve wraps around head of fibula
  2. between skin and bony projection –crushing injury e.g. plaster applied too tightly
  3. between retinacula and bone – squashing injury, small amount of welling with no where to go
  4. on bone – from fracture
71
Q

Functional loss and deformity from a lesion

A

can cause:

  1. paralysis/ paresis
  2. loss of sensation
  3. seen distal to the point of the lesion.
72
Q

How does functional loss &deformity occur due to a lesion?

A

action potential is inhibited and stopped, meaning the message travelling along the nerve is either weakened/ prevented.

73
Q

Femoral nerve vulnerable site

A

Body of psoas muscle, iliopsoas groove and at inguinal ligament = find and have movement as they lie above the inguinal ligament

74
Q

Femoral nerve lesion effect

A
  1. quad fem, sartorius, and pectineus experience motor loss

2. loss of skin sensation on the medial and anterior thigh, medial leg and foot

75
Q

Obturator nerve vulnerable site

A

inferior aspect of pubic ramus and obturator foramen

76
Q

Obturator nerve lesion effect

A

Weakness of thigh adduction, external rotation of thigh, small numbness of medial thigh

77
Q

Sciatic nerve vulnerable site

A

from pelvis to the distal thigh, between greater sciatic notch and ischial tuberosity

78
Q

Sciatic nerve lesion functional loss

A

motion and sensation of posterior, medial, and lateral leg

79
Q

Tibial nerve vulnerable site

A

Popliteal fossa region, laceration of popliteal area, posterior dislocation

80
Q

Tibial nerve lesion functional loss

A

numbness, pain, tingling and weakness of knee or foot

81
Q

Common peroneal nerve vulnerable site

A

Posterior and lateral aspect of knee joint complex

82
Q

Common peroneal nerve lesions functional loss

A

lateral and anterior function of leg, skin of upper lateral and lower posterolateral leg

83
Q

Superficial Peroneal nerve vulnerable site

A

areas around the fibular head, between the tibia and fibula joint

84
Q

Superficial Peroneal nerve functional loss

A

peroneus muscle skin of anterolateral aspect of the leg and greater part of dorsum of the foot

85
Q

Deep peroneal nerve vulnerable site

A

Injury to the knee, fibula fracture, fibula head and neck, and lateral aspect of knee

86
Q

Deep peroneal nerve lesion functional loss

A

lower leg muscles function, dorsal webspace, foot functions

87
Q

Myotome

A
  • a group of muscles supplied by one spinal nerve (via both its dorsal and ventral rami)
  • often described in terms of the movements that these muscles bring about (e.g. hip flexion)
88
Q

Myotome and segmental innervation

A

Mass of muscle innervated by a single spinal nerve

89
Q

Lower Limb myotomes things to remember

A

o Two segments per movement
o Consecutive pairs of antagonistic movement
o Begin on anterior surface
o Drop a joint, drop a segment

90
Q

Dermatomes (sensory version of myotome)

A
  • An area of skin supplied by one spinal nerve
  • Usually a long, elongated strip of skin
  • Overlap and variation
  • Less clinically reliable than myotomes
91
Q

Hip Jt Mvmts in segmental innervation

A

Extension

Flexion

92
Q

Hip Jt Myotomes

A

Flexion - L2 L3

Extension - L4, L5

93
Q

Knee jt mvmts

A

extension

flexion

94
Q

Knee jt myotomes

A

Ext- L3,L4

Flex- L5, S1

95
Q

Ankle jt mvmts

A

Dorsiflexion

Plantarflexion

96
Q

Ankle jt myotomes

A

Dorsi- L4,L5

Plantar- S1, S2

97
Q

Toe jt mvmt

A

Ext

Flex

98
Q

Ankle Jt myotomes

A

Ext- L5, S1

Flex- S1, S2

99
Q

Lesions femoral nerve- at inguinal ligament

A
Motor loss in:
- quad fem
- sartorius
- pectineus 
Sensory loss:
- loss of skin sensation on the middle and anterior thigh , medial leg and foot
100
Q

Segmental Innervation

A
  • the distribution of the motor and sensory neurons of the spinal neurons of the spinal nerve
  • established during the embryonic period
101
Q

Distinguishing between a spinal nerve & peripheral nerve lesion

A
  • Example
    o A patient comes to you with symptoms that include weak leg extension and tingling down the medial part of their leg into their foot
  • How to distinguish is the problem due to a central, or spinal, nerve lesion or is it a peripheral nerve problem?
102
Q

Femoral nerve motor distribution

A

Quad fem (hip F, knee E)
Iliacus (hip F)
Pectineus (hip F)

103
Q

Femoral nerve sensory distribution

A
  • skin of the anterior and medial thigh

- skin of the medial leg and foot (via saphenous branch)

104
Q

L4 Myotomes

A
  • hip extension (myotomes usually described by mvmts they produce)
  • knee ext
  • ankle DF
105
Q

L4 Dermatomes

A
  • skin of the lateral thigh
  • skin of the anterior knee
  • skin of the medial leg & foot
106
Q

Proving it is a spinal lesion Clinical signs (L4 vs femoral)

A
  • Weakness in leg extension
  • altered sensation in skin over medial leg & foot
    From this info, not enough to make diagnosis –> need further testing LOOK FOR DIFFERENCES
107
Q

What would I write? (L4 vs femoral)

A
  1. i would test hip ext
  2. i would test ankle df
  3. i would expect to find weakness on the affected side
  4. although less clinically reliable, i would also do a skin sensation test. i would expect to find altered sensation in a strip of skin over the lateral thigh/ anterior knee
108
Q

L4 vs Common Peroneal

A

• Patient presents with weakness in ankle dorsiflexion and complains of numbness over their big toe. How would you prove it is an L4 lesion (Tip: for the common peroneal you have to factor in its branches)

109
Q

L5 vs Deep Peroneal

A

• Patient presents with weakness in ankle dorsiflexion and toe extension, and also complains of pins and needles over the top of digits 2,3 and 4. How would you prove it is a L5 lesion?

110
Q

L5 vs Tibial

A

• Patient presents with weakness in knee flexion and tingling on the medial plantar aspect of their foot. How would you prove it is a L5 lesion? (Tip: think about the branches of the tibial nerve)

111
Q

L5 myotomes

A
  • Hip ext
  • Knee flex
  • Ankle dorsi
  • Toe ext
112
Q

L5 dermatome

A
  • Lateral fem condyle
  • Anterior ankle
  • Dorsal surface of the foot b/w 2nd and fourth digits
113
Q

Tibial nerve motor dist

A
  • Gastrocs, soleus, plantaris, TP, FHL, FDL
  • Ankle plantarflexion
  • Ankle inversion
  • Knee flexion
  • Toe flexion
114
Q

Tibial nerve sensory dist

A
  • Skin of the medial 3 and ½ digits and corresponding sole
  • Skin of the lateral and posterior leg, heel and skin of the lateral side of the sole
  • Skin of the lateral and posterior leg
115
Q

L5 vs…

A

To prove that it is a L5 lesion i would test all of the not crossed off muscles (hip ext, ankle dorsi, toe ext) and expect weakness on the affected side. Although less clinically reliable I would also test the dermatomes…

116
Q

S2 vs Tibial

A

• Patient presents with weakness in plantarflexion and pins and needles over the heel of their foot. How would you prove it is a S2 lesion? (Tip: think about the branches of the tibial nerve)