Sacral Plexus Flashcards
1
Q
The sacral plexus is formed by what rami?
A
Anterior primary rami of L4, L5, S1-S3 and part of S4
2
Q
Contributions of L4 and L5 are from the _____ trunk
A
Lumbosacral
3
Q
The sacral plexus forms of the anterior surface of what muscle?
A
Piriformis
4
Q
The sacral plexus divides into anterior and posterior divisions after exiting the ____?
A
IVF/sacral foremen
5
Q
What nerve roots supply the nerve to the quadratic femoris and gemellus inferior?
A
L4, L5, S1
6
Q
The nerve to the quadratus femoris and gemellus inferior leaves the pelvis through what?
A
Greater sciatic foramen
7
Q
The nerve to the quadratus femoris and gemellus inferior supply muscles that have what two actions?
A
Lateral rotation and addiction of the thigh
8
Q
What nerve roots form the nerve to the obturator inter us and gemellus superior?
A
L5, S1 and S2
9
Q
What opening does the nerve to the obturator internus and gemellus superior leave the pelvis through?
A
Greater sciatic foramen
10
Q
After the nerve to the obturator internus and gemellus superior leave the pelvis through the sciatic foramen, it gives off branches to what?
A
The gemellus superior
11
Q
The nerve to the obturator internus and gemellus superior re-enters the pelvis through what to supply what?
A
Lesser sciatic foramen
Obturator internus
12
Q
The nerve to the obturator internus and gemellus superior supply muscles that have what two actions?
A
Lateral rotation and abduction of the thigh
13
Q
The pudendal nerve contains fibers from?
A
S2, S3, S4
14
Q
The pudendal nerve exits the pelvic cavity through the ____ _____ _____ and arches around the ______ _______ and into the perineum via the _____ ____ ______
A
Greater sciatic foramen
Ischial spine
Lesser sciatic foramen
15
Q
After the pudendal nerve re-enters through the lesser sciatic foramen, it travels in the _______ _______ inferior to the pubic symphysis to reach the dorsal side of the _____ (males) or _____ (females)
A
Pudendal canal
Penis
Clitoris
16
Q
Do some branches come off the pudendal nerve within the pudendal canal?
A
Yes
17
Q
What are the names of the branches that come off the pudendal nerve within the pudendal canal?
A
Inferior rectal nerves
Perineal nerve
Dorsal nerve of the penis/clitoris (terminal nerve of the pudendal nerve)
18
Q
What is the terminal nerve of the pudendal nerve?
A
Dorsal nerve of the penis/clitoris
19
Q
The inferior rectal nerves carry _______ information from what two areas?
A
Sensory
- Skin around the anus
- Inferior 2/3 of the anal canal
20
Q
What nerve carries sensory information from the skin around the anus and the inferior 2/3 of the anal canal?
A
Inferior rectal nerves
21
Q
The inferior rectal nerve has motor supply to what?
A
External anal sphincter
22
Q
What nerve contains motor supply to the external anal sphincter
A
Inferior rectal nerves
23
Q
The _______ nerve is a branch of the pudendal nerve and splits into deep and superficial branches
A
Perineal nerve
24
Q
The deep branch of the perineal nerve have motor supply to what 4 muscles?
A
- External anal sphincter
- Bulbospongiosus
- Ischiocavernosus
- Superficial transverse perineus
25
What nerve has motor supply to the following muscles: external anal sphincter, bulbospongiosus, ischiocavernosus, and superficial transferee perineus?
Deep branch of the perineal N.
26
Superficial branches of the perineal N carry sensory fibers from what in males and females?
Males: posterior scrotum, urethral mucosa, and bulb of the penis
Females: labium majus, external urethral orifice, vestibule
27
What nerve carries sensory fibers from the posterior scrotum, urethral mucosa, and bulb of the penis in males and labium majus, external urethral orifice, and vestibule in females?
Superficial branches of perineal N.
28
What muscles does the terminal branch of the pudendal N, the dorsal nerve of the penis/clitoris, supply?
Deep transverse perineus
| Urethral sphincter muscles
29
What nerve supplies the deep transverse perineus and the urethral sphincter muscles?
Dorsal nerve of the penis/clitoris
30
The dorsal nerve of the penis/clitoris carries sensory fibers from what in males and females?
Males: corpus cavernosum, glans penis, and skin covering penis
Females: corpus cavernosum, clitoris
31
What nerve carries sensory fibers from the corpus cavernosum, glans penis, and skin covering the penis in males and corpus cavernosum, and the clitoris in females?
Dorsal nerve of the penis/clitoris
32
Individual muscular branches off the sacral plexus contain fibers from ____ and supply the _____ _______ and ______ muscles
S4
Lavatory ani
Coccygeus
33
The pelvic splanchnic nerves contain fibers from?
S2, S3, S4
34
What nerves are branches of the posterior division of the sacral plexus?
1. Nerve to piriformis
2. Superior gluteal N
3. Inferior gluteal N.
4. Perforating cutaneous N
35
Nerve to the piriformis what fibers to the piriformis?
S1 and S2
36
The superior gluteal N. Is made of what fibers?
L4, L5, S1
37
The superior gluteal N. Leaves the pelvis through _________, superior/inferior to the piriformis and splits into superior and inferior branches
Greater sciatic foramen, SUPERIOR
38
What does the superior branch of the superior gluteal N. Supply?
Gluteus mediums and minimus
39
What does the inferior branch of the superior gluteal N supply?
Gluteus mediums, gluteus minimus and the tensor fascia lata
40
The inferior gluteal nerve carries fibers from?
L5, S1, and S2
41
The inferior gluteal nerve leaves the pelvis through the ______ superior/inferior to the piriformis and innervates what?
Greater sciatic foramen, SUPERIOR
| Gluteus Maximus
42
What nerve supplies the gluteus Maximus?
Inferior gluteal N
43
The perforating cutaneous nerve is made up of what fibers?
S2 and S3
44
The perforating cutaneous nerves travels through what structure and then ultimately reaches what structure?
Sacrotuberous ligament
| Lower medial aspect of the buttocks
45
The perforating cutaneous nerve may instead be formed by a branch off the ______ nerve or may even be ______
Pudendal
| Absent
46
What nerve may also be formed from the pudendal nerve or be absent?
Perforating cutaneous nerve
47
What two nerves are formed by branches of both the anterior and posterior division of the sacral plexus?
1. Posterior cutaneous nerve of the thigh
| 2. Sciatic N
48
what fibers form the posterior cutaneous nerve of the thigh?
S2 and S3 from the anterior division
| S1 and S2 fro the posterior division
49
What nerve is formed by S2 and S3 from the anterior division and S1 and S2 from the posterior divisions?
Posterior cutaneous nerve of the thigh
50
The posterior cutaneous nerve of the thigh leaves the pelvis through the __________ and ascends/descends through the posterior thigh and inferior leg to where it ultimately communicates with the ______ nerve
Greater sciatic foramen
Descends
Sural
51
What does the posterior cutaneous nerve of the thigh supply?
Skin on the posterior and medial thigh
52
What nerve supplied the skin of the posterior and medial thigh?
Posterior cutaneous nerve of the thigh
53
What is the largest nerve in the human body?
Sciatic nerve
54
What is the diameter of the sciatic nerve?
2cm
55
The sciatic nerve is a combination of what two nerves?
Tibial and common fibular N.
56
What fibers make up the tibial nerve?
L4-S3 from the anterior division
57
What fibers make up the common fibular nerve?
L4-S2 from the posterior division
58
The sciatic nerve leaves the pelvis through _______ within a _______ ______ above/below the piriformis muscle?
Greater sciatic foramen
Common sheath
BELOW!
59
What nerve exits the pelvis through the greater sciatic foramen BELOW the piriformis muscle?
Sciatic N
60
After the sciatic nerve exits the greater sciatic foramen below the piriformis, it continues inferior on the posterior aspect of what muscle?
Adductor magnus
61
2/3 of the way to the knee, what happens to the sciatic nerve?
It splits into the common fibular and tibial nerves.
62
Is the point where the sciatic nerve splits into the common fibular and tibial nerve variable?
Yes.
63
The common fibular nerve gives off branches to what muscle in the thigh before separating from the tibial nerve?
Biceps femoris (short head)
64
After separating from the tibial nerve, the common fibular nerve courses around the _____ aspect of the fibula. Upon reaching the anterior-lateral aspect of the leg it gives off an _______ branch to the ____ _____.
Lateral
| Articular, knee joint
65
What two branches are given off the common fibular nerve along the lateral aspect of the popliteal fossa?
1. Lateral sural cutaneous nerve
| 2. Fibular communicating branch
66
Where are the lateral sural cutaneous nerve and the fibular communicating branches given off the common fibular N?
Along the lateral aspect of the popliteal fossa
67
What does the lateral sural cutaneous nerve supply?
Skin no the lateral aspect of the leg
68
the fibular communicating branch forms the _____ nerve after combining with the _____ ______ _____ nerve
Sural
| Medial sural cutaneous nerve
69
What two nerves does the common fibular nerve split into after giving off branches in the lateral popliteal fossa?
1. Superficial fibular nerve
| 2. Deep fibular nerve
70
The superficial fibular nerve travels inferior between the ____ _____ and the _____ down to the dorsum of the foot.
Fibular is longus and fibula
71
What nerve travels inferior between the fibularis longus and the fibula to the dorsum to supply the fibularis longus/brevis?
Superficial fibular nerve
72
What two muscles does the superficial fibular nerve supply?
1. Fibularis longus
| 2. Fibularis brevis
73
After the superficial fibular nerve branches to supply the fibularis longus and brevis it splits into what two additional nerves?
1. Medial dorsal cutaneous nerve
| 2. Intermediate dorsal cutaneous nerve
74
What do the medial and intermediate dorsal cutaneous nerves supply together?
Skin over the dorsum of the foot
| (Except for the skin between the first two toes)
75
What two nerves supply the skin over the dorsum of the foot (except for the skin between the first two toes)?
Medial and intermediate dorsal cutaneous nerves
76
The deep fibular nerves runs inferiorly along the _____ _____ to reach the dorsum of the foot to supply the extensor muscles of the foot and toes
Tibialis anterior
77
What 7 muscles/areas does the deep fibular nerve supply?
```
1. Tibialis anterior
2/3. Extensor digitorum longus/brevis
4/5. Extensor hallucinate longus/brevis
6. Fibularis tertius
7. Sensory- skin between the first two toes (terminal branch of the deep fibular nerve)
```
78
What nerve supplies the tibialis anterior?
Deep fibular N
79
What nerve supplies the extensor digitorum longus/brevis?
Deep fibular N
80
What nerve supplies the extensor hallucis longus/brevis?
Deep fibular N
81
What nerve supplies the fibularis tertius?
Deep fibular N
82
What nerve supplies the skin between the first and second toes?
Deep fibular nerve
83
What clinical finding might you see if there was damage to the common fibular nerve?
Steppage gait
84
What fibers make up the tibial nerve?
L4-S3
85
Is the common fibular or tibial nerve larger?
Tibial
86
while still combined with the common fibular nerve, tibial nerve fibers are sent to what 4 muscles?
1. Biceps femoris (long head)
2. Semitendinosus
3. Semimembranosus
4. Adductor magnus
87
What types of branches does the tibial nerve give off in the popliteal fossa?
Articular branch
muscular branch
Popliteal branch
Medial sural cutaneous nerve
88
The articular branch that is given off by the tibial nerve in the popliteal fossa supplies what?
The knee joint
89
The muscular branches that the tibial nerve gives off in the popliteal fossa supply what?
1. Popliteus
2. Gastrocnemius
3. Soles
4. Plantaris
90
What nerve/branch supply the following muscles: popliteus, gastrocnemius, soleus, plantaris?
The muscular branch of the tibial nerve
91
The popliteal branch travels inferior to give rise to the _____ ____ __ __ _____
Interosseous nerve of the leg
92
The interosseous nerve of the leg travels along the posterior surface of the _______ ______ and carries _______ informations from the _______ ________, _______, ________?
Interosseous membrane
Sensory
Tibial periosteum, ankle and tibiofibular joints
93
What nerve carries information from the tibial periosteum, ankle and tibiofibular joints?
The interosseous nerve of the leg
94
In the leg the tibial nerve gives rise to both _____ and ______ sensory branches.
Muscular and sensory
95
The muscular branches of the tibial nerve in the leg supply what 3 muscles?
Tibialis posterior
Flexor digitorum longus
Flexor hallucis longus
96
What nerve/branch supply the tibialis posterior, flexor digitorum longus and hallucis longus muscles?
Muscular branch of the tibial nerve (in the leg)
97
What is the name for the sensory branches of the tibial nerve in the leg?
The medial calcaneal branches
98
The medial calcaneal branches supply what?
The skin over the medial heel
99
What branches supply the skin over the medial heel?
The medial calcaneal branches (of the tibial nerve)
100
The tibial nerve travels around the _____ _____ to the plantar surface of the food and divide into two terminal branches: _____ _____ nerve, and ______ ______ nerve.
Medial malleolus
| Medial plantar nerve and lateral plantar nerve
101
What are the two terminal branches of the tibial nerve on the plantar surface of the foot?
Medial and lateral plantar nerves
102
The medial plantar nerve sends motor fibers to?
1. Abductor hallucis
2. Flexor digitorum brevis
3. Flexor digitorum longus
103
What nerve supplies the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis?
Medial plantar nerve (terminal branch of the tibial nerve)
104
After the medial plantar nerve supplies the abductor hallucis, flexor digitorum brevis and flexor hallucis brevis, the medial plantar nerve divides into ____ ____ _____ nerves
Common plantar digital
105
The common plantar digital nerves have motor supply to what?
1st lumbrical
106
The common plantar digital nerves have sensory supply to where?
Skin between the toes by way of the proper plantar digital nerves
107
Sensory supply to the skin between the toes from the tibial nerve is supplied by what nerves?
Proper plantar digital nerves
108
What does the proper plantar digital nerves supply?
Skin between the toes
109
The lateral plantar nerve divides into what?
Superficial and deep branches
110
The superficial branch off the lateral plantar nerve supplies what?
Skin around the 5th digit
111
What supplies the skin around the fifth digit?
The superficial branch of the lateral plantar nerve (a branch of the tibial nerve)
112
The deep branch of the lateral plantar nerve supplies motor fibers to what 6 muscles?
1. Adductor hallucis
2. Flexor digiti minimi brevis
3. Abductor digiti minimi
4. Quadratus plantae
5. Lateral lumbricals
6. Interossei muscles
113
What branch/nerve supply the following: adductor hallucis, flexor digiti minimi brevis, abductor digiti minimi, quadratus plantae, lateral lumbricals, and the interossei muscles?
Deep branch of the lateral plantar nerve (branch of the tibial nerve)
114
What are some clinical considerations regarding damage to the tibial nerve?
1. Flexor paralysis
2. Hammer toes (distal phalanx of metatarsal joint abnormally flexed, while other joints are in extension)
3. Claw foot (tarsal tunnel syndrome)
115
Where is the tarsal tunnel located?
Medial/posterior malleolus
116
How many sacral spinal nerves are there?
5 pairs
117
The sacral spinal nerves descend inside _____, and form much of the ___ _____
```
Dura
Cauda equina (~L2)
```
118
Each sacral nerve divides into an ____ and ______ ____ _____
Anterior and posterior primary ramus
119
The posterior primary rami of s1-s4 travel through the four ____ _____. S5 travels through the _____ ____
Sacral foramina
| Sacral hiatus
120
What sacral rami travel through the sacral foramina?
Posterior primary rami of s1-s4
121
What sacral rami travel through the sacral hiatus
Posterior primary rami of s5
122
The posterior primary rami of ______ divide into ____ and ____ branches
S1-s3
| Medial and lateral
123
The medial branches of posterior primary rami of s1-s3 supply what?
The adjacent multifidi
124
The lateral branches of the posterior primary ramus of s1-s3 supply what? (Also L4/l5)
Skin over buttock?
125
What supply the skin of the multifidi in the sacrum>
Medial branch of posterior primary rami of s1-s3
126
What supply the skin to the buttock?
Lateral branches of posterior primary rami of s1-s3 and L4/l5
127
The posterior primary rami of _______ unite with the ______ ______ rami to supply the skin over the coccyx
S4-s5
| Coccygeal posterior rami
128
What supply the skin over the coccyx?
The posterior primary rami of s4-s5 and the coccygeal posterior rami
129
The anterior primary rami of s1-s4 travel through the four _____ _____ ____ while the s5 travels through the _____ _____
Anterior sacral foramina
| Sacral hiatus
130
The anterior primary rami of s1-s4 contribute to what?
Sacral plexus
131
The anterior primary rami of s4/s5 contribute to what?
Coccygeal pleaxus
132
What are the two communications with the sympathetic trunk to the sacral nerves?
1. 3-4 sacral sympathetic ganglia
| 2. Anterior primary ramus each have postganglionic sympathetic fibers via gray ramus communicans
133
What forms the coccygeal plexus?
S4, s5, Co1
134
The s4, s5, co1 nerves combine and give rise to _________nerves that carry sensory information from where?
Anococcygeal nerves
| Skin adjacent to the coccyx and anus
135
What supply the skin adjacent to the coccyx and anus?
Anococcygeal nerves
