Sacral Spinal Nerves and Coccygeal Plexus Flashcards Preview

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Flashcards in Sacral Spinal Nerves and Coccygeal Plexus Deck (15)
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1
Q

How many sacral spinal nerves typically exist?

A

10 (5 pairs)

2
Q

Do sacral spinal nerves descend inside or outside of the dura?

A

inside (form much of the cauda equina)

3
Q

T/F: Each sacral spinal nerve divides into an anterior and a posterior primary ramus.

A

True

4
Q

Which nerves travel through the sacral foramina

A

sacral spinal nerves (S1-S4 anterior primary rami through anterior sacral foramina, S1-S4 posterior primary rami through posterior sacral foramina)

5
Q

What muscles do the medial branches of the posterior primary rami of S1-S3 supply?

A

adjacent multifidi

6
Q

The lateral branches of the posterior primary rami of S1-S3 combine with branches from what nerves to supply the skin over the buttocks?

A

L5 and S4

7
Q

What do the posterior primary rami of S4 and S5 combine with to supply the skin over the coccyx?

A

coccygeal posterior rami

8
Q

Which sacral primary rami travel through the sacral hiatus?

A

anterior and posterior primary rami of S5

9
Q

T/F: the posterior primary ramus of S4 does not divide into medial and lateral branches.

A

True

10
Q

Which sacral spinal nerve contributes to both the sacral plexus and the coccygeal plexus?

A

S4 (S1-S4=sacral plexus, S4-Co1=coccygeal plexus

11
Q

How many sacral sympathetic ganglia usually exist?

A

usually 3 or 4

12
Q

T/F: The anterior primary ramus of each sacral nerve will receive postganglionic sympathetic fibers via a white ramus communicans.

A

False; via a gray ramus communicans

13
Q

What forms the coccygeal plexus?

A

anterior rami of S4, S5, and Co 1

14
Q

What nerves are produced from the coccygeal plexus?

A

anococcygeal nerves

15
Q

What do the anococcygeal nerves supply?

A

sensory info from the skin adjacent to the coccyx and anus (“anal pucker” response)