Sacral plexus Flashcards Preview

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Flashcards in Sacral plexus Deck (25):
1

What spinal roots make up the sacral plexus

S1-4 and contributions from L4-5

2

Location of sacral plexus

Surface of posterior pelvic wall, anterior to piriformis

3

How are the lumbar and sacral plexi joined

By lumbosacral trunk from combination of roots L4-5

4

What do the spinal roots divide into

Cords

5

What do the cords combine to form and how many

5 branches (major peripheral nerves)

6

What are the branches of the sacral plexus

Superior gluteal nerve,
Inferior gluteal nerve,
Sciatic nerve (covered in separate deck),
Posterior femoral cutaneous nerve/posterior cutaneous nerve of thigh
Pudendal nerve
(Some Irish sailors pester polly)

7

Destination of branches of sacral plexus

1. Leave pelvis via great sciatic foramen
2. Remain in pelvis

8

Roots of superior gluteal nerve

L4-5 and S1

9

Course of superior gluteal nerve

Leaves pelvis via great sciatic foramen, entering gluteal region superior to piriformis

10

Motor Innervation of superior gluteal nerve

Gluteus minimus,
Gluteus medius,
Tensor fascia lata

11

Sensory Innervation of superior gluteal nerve

None (entirely motor)

12

Roots of inferior gluteal nerve

L5 and S1-2

13

Course of inferior gluteal nerve

Leaves pelvis via great sciatic foramen, entering gluteal region inferior to piriformis

14

Motor Innervation of inferior gluteal nerve

Gluteus maximus

15

Sensory Innervation of inferior gluteal nerve

None (entirely motor)

16

Roots of posterior cutaneous nerve of thigh

S1-3

17

Course of posterior cutaneous nerve of thigh

Leaves pelvis via great sciatic foramen, entering gluteal region inferior to piriformis.
It then descends deep to gluteus maximus and runs down back of thigh to knee

18

Motor Innervation of posterior cutaneous nerve of thigh

None

19

Sensory Innervation of posterior cutaneous nerve of thigh

Skin over posterior thigh and leg
Skin over perineum

20

Roots of pudendal nerve

S2-4

21

Course of pudendal nerve

Leaves pelvis via great sciatic foramen then re-enters via lesser sciatic foramen.
It moves anterosuperiorly along lateral wall of ischiorectal fossa and terminates by dividing into several branches

22

Motor Innervation of pudendal nerve

Skeletal muscles in perineum,
External urethral sphincter,
External anal sphincter,
Levator ani

23

Sensory Innervation of pudendal nerve

Penis,
Clitoris,
Most skin over perineum

24

Minor branches of sacral plexus

Nerve to piriformis S2,
Nerve to obturator internus L5 and S1-2,
Nerve to quadrator femoris L4-5 and S1

(Root values may not be correct)

25

Anterior or posterior rami

anterior

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