Sacral Plexus Part 2 (Posterior division) Flashcards Preview

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Flashcards in Sacral Plexus Part 2 (Posterior division) Deck (40)
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1

What nerve supplies the piriformis muscle and which roots contribute fibers?

nerve to the piriformis; fibers from S1 and S2

2

What roots contribute fibers to the superior gluteal nerve?

L4, L5, and S1

3

After the superior gluteal nerve exits the pelvis via the greater sciatic foramen, what does it split into?

superior and inferior branches

4

What muscle does the superior gluteal nerve exit the pelivs superior to?

piriformis

5

T/F: the inferior branches of the superior gluteal nerve supply the gluteus maximus.

False; inferior branches of superior gluteal nerve supply the gluteus medius, gluteus minimis and tensor fascia lata

6

What muscles are supplied by the superior branches of the superior gluteal nerve?

gluteus medius and minimus

7

What nerve leaves the pelvis via the greater sciatic foramen, inferior to the piriformis, to supply the gluteus maximus? what roots contribute fibers?

inferior gluteal nerve;
L5, S1, and S2

8

What roots contribute to the perforating cutaneous nerve?

S2 and S3

9

How does the perforating cutaneous nerve get its name?

it penetrates the sacrotuberous ligament on its way to the lower medial aspects of the buttocks

10

T/F: the perforating cutaneous nerve may be formed by a branch off the pudendal nerve or be absent altogether.

True

11

what two nerves are formed by both anterior and posterior divisions of the sacral plexus?

posterior cutaneous nerve of the thigh and sciatic nerve

12

What roots/divisions form the posterior cutaneous nerve of the thigh?

anterior divisions of S2 and S3 and posterior divisions of S1 and S2

13

What nerve leaves the pelvis via the greater sciatic foramen, descends thru the posterior thigh and inferior to the leg where it ultimately communicates with the sural nerve?

posterior cutaneous nerve of the thigh

14

What skin is supplied by the posterior cutaneous nerve of the thigh?

skin of the posterior and medial thigh

15

What is the largest nerve in the human body?

sciatic nerve

16

The sciatic nerve is commonly about 2 cm in diameter and formed by two nerves. What are the two nerves that combine to form the sciatic nerve?

tibial and common fibular nerves

17

The tibial nerve is more medial than the common fibular nerve. Where do the fibers of the tibial nerve come from?

the anterior divisions of the L4-S3 nerves

18

Where do the fibers of the common fibular nerve come from?

The posterior divisions of the L4-S2

19

T/F: the sciatic nerve leaves the pelvis via the greater sciatic foramen, below the piriformis, with both parts in individual sheaths.

False; both parts are in a common sheath

20

What muscle does the sciatic nerve travel on the posterior aspect of in the thigh?

adductor magnus

21

Where does the sciatic nerve split into its tibial and common fibular components?

about 2/3 of the way to the knee (lower 3rd of the thigh)

22

T/F: the point at which the sciatic nerve may be further or the two parts may be separate all the way.

True

23

What muscle does the common fibular nerve give off branches to in the thigh before separating from tibial nerve fibers?

biceps femoris (short head)

24

After separating from the tibial nerve, the common fibular nerve follows its course around the fibula where it gives off an articular branch. What joint does the common fibular nerve send an articular branch to upon reaching the antero-lateral aspect of the leg?

knee joint

25

Where are the two sensory branches given off of the common fibular nerve? What are they named?

given off as the nerve courses around the lateral aspect of the politeal fossa;
lateral sural cutaneous nerve and fibular communicating branch

26

What supplies the skin on the lateral aspect of the leg?

lateral sural cutaneous nerve

27

What nerve forms the sural nerve after combining with the medial sural cutaneous nerve?

fibular communicating branch

28

After giving off the two sensory branches what does the common fibular nerve divide into?

superficial fibular nerve and the deep fibular nerve

29

What two structures does the superficial fibular nerve travel between on it way to the dorsum of the foot?

fibularis longus and the fibula

30

What does the superficial fibular nerve split into in order to supply the skin over the dorsum of the foot?

medial dorsal cutaneous nerve and the intermediate dorsal cutaneous nerve