outline 13: lumbar plexus Flashcards
1
Q
What are the nerve roots of the lumbar plexus
A
(Anterior rami of) L1-L4
2
Q
The lumbar plexus generally innervates which muscle groups?
A
- posterior abdominal wall muscles
- anterior thigh muscles
- medial thigh muscles
3
Q
Does the lumbar plexus innervate anything below the knee? If so, what?
A
yes; cutaneous to medial leg
4
Q
where does the lumbar plexus form?
A
psoas major
5
Q
what nerves are associated with the cremaster reflex?
A
ilioinguinal (sensory) and genitofemoral (motor)
6
Q
What nerve(s) emerge(s) from the anterior border of psoas major
A
genitofemoral N
7
Q
what nerve(s) emerge(s) off of the lateral border of psoas major
A
subcostal N iliohypogastric N ilioinguinal N lateral femoral cutaneous N fermoral N
8
Q
What is the nerve root of the genitofemoral N
A
L1-2
9
Q
what does the genitofemoral N innervate
A
- cutaneous to genital region and proximal anterior thigh
2. cremaster muscle
10
Q
nerve root(s) of subcostal N
A
T12
11
Q
nerve root(s) of iliohypogastric N
A
L1
12
Q
ilioinguinal nerve root(s)
A
L1
13
Q
lateral femoral cutaneous nerve root(s)
A
L2-L3
14
Q
femoral nerve root(s)
A
L2,L3,L4
15
Q
what does ilihypogastric nerve innervate
A
- cutaneous to gluteal and lower abdomen
2. motor to lower abdomen
16
Q
what does ilioinguinal nerve innervate
A
- cutaneous to inguinal (proximal medial thigh) region
2. motor to lower abdominals
17
Q
what does the lateral femoral cutaneous innervate
A
cutaneous to anterolateral thigh (as far as knee)
18
Q
what does the femoral N innervate
A
- psoas major and iliacus
- anterior compartment thigh muscles
- pectineus
- articular branches to hip and knee joints
- cutaneous
19
Q
what are the cutaneous nerve branches of the femoral N
A
- anterior femoral cutaneous N
2. saphenous N
20
Q
what does anterior femoral cutaneous N innervate
A
most of the anterior thigh
21
Q
what does the saphenous N innervate
A
medial leg under knee
22
Q
what nerve(s) emerge(s) from the medial border of psoas major
A
obturator N
23
Q
nerve root(s) of obturator N
A
L2,L3,L4
24
Q
what does the obturator N innervate
A
- adductor muscles (medial thigh muscles)
- obturator externus
- skin on medial mid-thigh
- articular branches to hip joint
25
Obturator externus is a muscle that (X) the hip. Functionally, it acts with muscles that have (Y) innervation, but it's innervated by (Z).
```
X = externally rotates
Y = sacral
Z = the obturator nerve
```
26
what are the roots of the lumbosacral trunk
L4-L5
27
(X) nerve root(s) contribute(s) to both lumbar and sacral plexi. What are its/their specific contributions?
```
X = L4
Contributions:
1. lumbosacral trunk
2. obturator N (medially)
3. femoral N (laterally)
```
28
Where does the sacral plexus form
anterior surface of piriformis
29
what does the sacral plexus innervate
1. posterior compartment thigh muscles
2. buttock
3. all of leg and foot below knee (except medial cutaneous leg)
30
what are the branches of the sacral plexus?
```
superior gluteal
inferior gluteal
N to obturator internus
N to quadratus femoris
branches to supply piriformis
posterior femoral cutaneous
pudendal
sciatic
```
31
The sacral plexus branches emerge (superior/inferior) to piriformis. Name exceptions, if any.
inferior; exception: superior gluteal nerve
32
what does the superior gluteal nerve innervate
gluteus medius and minimus, tensor fascia lata
33
what does inferior gluteal nerve innervate
gluteal maximus
34
what does nerve to obturator internus innervate
obturator internus, and superior gemellus
35
what does nerve to quadrature femoris innervate
quadartus femoris, inferior gemellus
36
what nerve innervates more surface area than other cutaneous N
posterior femoral cutaneous
37
what does the pudendal nerve innervate
1. sensory to external genitilia
| 2. perineum- skin and muscles
38
The sciatic nerve is actually 2 nerves in a sheath, the lateral most is (X) and the medial most is (Y).
```
X = common peroneal N
Y = tibial N
```
39
what is the sciatic nerve in between
greater trochanter of the femur and ischial tuberosity
40
Which ligament is posterior to the pudendal N and N to obturator
sacrotuberous ligament
41
Which ligament is anterior to pudendal N and N to obturator
sacrospinous ligament
42
what does the tibial N innervate
1. most posterior thigh muscles
2. popliteal fossa branches
3. ALL posterior leg muscles
4. medial calcaneal (cut. heel)
5. medial and lateral (cutaneous) plantar
43
Which posterior thigh muscles are innervated by the tibial nerve?
1. biceps femurs (long head ONLY)
2. semitendinosus
3. semimembranosus
4. adductor magnus (posterior/extensor head)
44
Does the common peroneal nerve innervate any posterior thigh muscles? If so, which?
yes; short head biceps femoris
45
what are the branches of the tibial N in the popliteal fossa
medial sural cutaneous, muscular branches to gastrocnemius and plantaris, articular branches
46
what is the action of most of the posterior leg muscles
plantar flexion
47
T/F: Short head of biceps femoris shares its nerve innervation with one other thigh muscle.
False; common peroneal nerve has only one innervation in the thigh (short head biceps)
48
what branches, if any, does the common peroneal N give off in the popliteal fossa?
fibular communicating branch
| lateral sural cutaneous
49
After passing through the popliteal fossa, the common peroneal nerve travels (X) and does what?
X = around the head/neck of fibula
| Divides
50
what does the common peroneal divide into
superficial peroneal
| deep peroneal
51
what does the superficial peroneal supply
1. lateral compartment leg muscles (peroneus longus and brevis)
2. cutaneous to lower anterolateral leg and dorsum of foot
52
what does the deep peroneal supply
1. recurrent branch to knee joint
2. anterior compartment leg muscles (dorsal flexors)
3. extensor digitorum brevis on foot
4. cutaneous: wedge between toes 1 and 2
53
Dorsiflexors are supplied by (X) nerve. Plantar flexors are supplied by (Y) nerve.
```
X = deep peroneal
Y = tibial
```
54
what are the nerve roots of the common peroneal N
L4-5, S1-2
55
what does the sural N innervate
lower posterolateral leg
56
Difference(s) between the musculature on back of hand and the top of foot:
there are no muscles on the back of the hand, but extensor digitorum is on the top of the foot
57
Nerve roots to superior gluteal nerve
L4-L5, S1
58
Nerve roots to inferior gluteal nerve
L5, S1-S2
59
Nerve roots to nerve to obturator internus
L5, S1-S2
60
Superior gemellus is innervated by which nerve? And inferior gemellus?
Sup: Nerve to obturator internus
Inf: Nerve to quadratus femoris
61
Nerve roots to nerve to quadratus femoris
L4-5, S1
62
What innervates piriformis? Name the nerve roots as well.
Anterior rami S1-S2
63
Nerve roots to posterior femoral cutaneous nerve
S1-S3
64
Nerve roots to pudendal nerve
S2-S4
65
Nerve roots to sciatic nerve
L4-L5, S1-S3
66
The tibial nerve gives off an extensive network of branches in the (X). Are these branches muscular, cutaneous, or articular branches?
X = popliteal fossa
| ALL (muscular, cutaneous, and articular branches are given off)
67
what innervates the cutaneous middle front of thigh
anterior femoral cut N
68
what innervates the lateral side of the thigh
lateral femoral cut N
69
what innervates proximal anterior thigh
genitofemoral N (femoral branch)
70
what innervates the proximal medial thigh
ilioinguinal N
71
what innervates a little distally to the proximal medial thigh
cut branch of obturator N
72
what innervates the middle of the posterior thigh
posterior femoral cut N
73
what innervates the medial leg
saphaneous N
74
what innervates the upper lateral leg
lateral sural cutaneous
75
what innervates the lower posterior lateral leg onto top of foot and the lateral-most edge of foot
sural N
76
what innervates the lower anterolateral leg and the whole top of the foot
superficial peroneal
77
what innervates the wedge between the 1st 2 toes
deep peroneal
78
what innervates the medial side of the bottom of your foot
medial plantar
79
what innervates the lateral side of the bottom of your foot
lateral plantar
80
what is the saphenous nerve a branch of
fermoral N
81
what is the lateral sural cut N a branch of
common peroneal on popliteal fossa
82
what is sural N a branch of
common peroneal comm branch and tibial Lateral medial sural cut
83
what are the medial and plantar nerves branches of
tibial N
84
what is the anterior femoral cut N a branch of
femoral N
85
what is the lateral femoral cut N a branch of
directly off of lumbar plexus
86
what is the obturator N a branch of
directly off of lumbar plexus
87
what is the posterior femoral cut N a branch of
directly off of sacral plexus
