Sacral Spinal Nerves and Sacral plexus

Question 1

How many pairs of sacral spinal nerves are there

Answer 1

5

Question 2

Which rami pass through the posterior sacral foramina

Answer 2

Posterior primary rami of S1-S4

Question 3

Where does the S5 posterior primary ramus travel

Answer 3

Through the sacral hiatus

Question 4

Which rami divide in medial and lateral branches

Answer 4

Posterior primary rami of S1-S3

Question 5

Which branches are motor, and which are cutaneous

Answer 5

Medial are motor, Lateral are cutaneous

Question 6

What do the medial branches supply

Answer 6

Adjacent multifidi

Question 7

What do the lateral branches supply after unite with branches from L5 and S4

Answer 7

Skin over buttocks

Question 8

Typically, how many sacral sympathetic ganglia are there

Answer 8

3-4

Question 9

What will the ant. primary rami of each sacral n. receive via a gray ramus communicans

Answer 9

Postganglionic sympathetic fibers

Question 10

What forms the sacral plexus

Answer 10

The anterior primary rami of L4, L5, S1-S3, and part of S4

Question 11

What nerve roots make up the lumbosacral trunk

Answer 11

L4 and L5

Question 12

Where is the sacral plexus located

Answer 12

On the anterior surface of the piriformis muscle

Question 13

Where does the quadratus femoris and gemellus inferior leave the pelvis

Answer 13

Greater sciatic foramen

Question 14

The N. to the obturator internus and gemellus superior leave the pelvis via _______ then re-enters via _______

Answer 14

Greater sciatic foramen; Lesser sciatic foramen

Question 15

How is the pudendal n. transmitted to the dorsal aspect of either the penis or clitoris

Answer 15

Pudendal canal

Question 16

What n. carries sensory info from the skin around the anus and inf. 2/3 of the anal canal

Answer 16

Inf. rectal nerves

Question 17

What n. gives the motor supply to the external anal sphincter

Answer 17

Inferior rectal nerves

Question 18

What supplies the External anal sphincter, bulbosponsiosus, ischiocavernosus, superficial transverse perineus

Answer 18

Deep branches of the perineal n.

Question 19

What do the superficial branches of the perineal n. supply in males

Answer 19

Sensory: post. scrotum, urethral mucosa, bulb of penis

Question 20

What do the superficial branches of the perineal n. supply in females

Answer 20

Sensory: labium majus, external urethral orifice, and vestibule

Question 21

What is the terminal branch of the pudendal n. in males/females

Answer 21

Dorsal n. of the penis/clitoris

Question 22

What n. supplies the deep transverse perineus and urethral sphincter muscles

Answer 22

Dorsal nerve of the penis/clitoris

Question 23

Muscular branches off the sacral plexus contain S4 fibers and supply what muscles

Answer 23

Levator ani and Coccygeus

Question 24

What n. roots make up the pelvic splanchnic n.

Answer 24

S2-S4

Question 25

What supplies the glut. medius and minimus

Answer 25

Superior branches of the superior gluteal n.

Question 26

What supplies the glut. medius, minimus, and TFL

Answer 26

Inf. branches of the superior gluteal n.

Question 27

What supplies the glut. maximus

Answer 27

Inf. gluteal n.

Question 28

What does the perforating cutaneous n. pierce

Answer 28

Sarcrotuberous ligament

Question 29

Which n. may be a branch of off the pudenal n. or absent

Answer 29

Perforating cutaneous n.

Question 30

What n. is formed from the ANT. divisions of S2 and S3 and POST. divisions of S1 and S2

Answer 30

Posterior cutaneous n. of the thigh

Question 31

The Sciatic n. is a combination of the more medial ______ and the more lateral __________

Answer 31

Tibial n.; Common fibular n.

Question 32

Most commonly, when does the sciatic n. divide

Answer 32

approx. 2/3 of the way to the knee

Question 33

What is the one muscle in the thigh supplied before the common fibular nerve separates from the tibial n. fibers

Answer 33

Biceps femoris (short head)

Question 34

What forms the sural n. after combining with the medial sural cutaneous n.

Answer 34

Fibular communicating branch

Question 35

What n. supplies the Fibularis longus and brevis

Answer 35

Superficial fibular n.

Question 36

The superficial fibular n. splits into what to nerves in order to supply the dorsum of the foot

Answer 36

Medial and Intermediate dorsal cutaneous nerves

Question 37

What is a good way to remember what m. the deep fibular n. supplies

Answer 37

The extensor muscles of the foot and toes: | Tib. anterior, Extensor digitorum longus/brevis, Extensor hallucis longus/brevis, Fibularis tertius

Question 38

What is steppage gait

Answer 38

Paralysis of the extensors, foot "slaps" the ground

Question 39

What m. are supplied by the tibial n. fibers when it is still with the common fibular

Answer 39

All hamstrings (except short head) and adductor magnus

Question 40

What does the tibial n. supply near the popliteal fossa

Answer 40

Articular branches and Popliteus, Gastroc, Soleus, Plantaris

Question 41

What carries sensory info from the tibial periosteium, ankle, and tibiofibular joints

Answer 41

Interosseous n. of the Leg from the Popliteal branch of the tibial n.

Question 42

What m. are supplied by the tibial n. in the leg

Answer 42

Flexor digitorum/hallucis longus and Tib posterior

Question 43

W n. supplies the skin over the medial heel

Answer 43

Medial calcaneal branches

Question 44

What has the motor supply to the abductor hallucis, flexor digitorum brevis, and flexor hallucis brevis

Answer 44

Medial plantar n.

Question 45

What has the motor supply to lumbricals 1&2 and sensory to skin btwn. toes via proper plantar digital nerves

Answer 45

Common plantar digital nerves

Question 46

What does the superficial branch of the lateral plantar n. supply

Answer 46

The skin around the 5th digit

Question 47

What forms the coccygeal plexus

Answer 47

Ant. rami of S4, S5, and Co1

Question 48

What nerves carry sensory info from the skin adjacent to the coccyx and anus

Answer 48

Anococcygeal nerves