Gluteal Region

Question 1

What nerves are responsible for the cutaneous innervation of the buttock?

Answer 1

The cluneal nerves: superior cluneal nerve (lateral branches of the dorsal primary rami of L1-L3), middle cluneal nerves (lateral branches of the dorsal primary rami of S1-S3), and inferior cluneal nerves (branches of posterior femoral cutaneous nerve)

Question 2

Which actions are performed by gluteal muscles?

Answer 2

Extension, abduction, medial/lateral rotation of the thigh

Question 3

What is the action of the gluteus maximus muscle?

Answer 3

It extends the thigh and is innervated by the inferior gluteal nerve and does lateral rotation. This is the muscle that helps you stand from a chair!

Question 4

What is the innervation and action of the gluteus medius muscle?

Answer 4

It functions to abduct and medially rotate the thigh. It is innervated by the superior gluteal nerve.

Question 5

What is the innervation and action of the gluteus minimus muscle?

Answer 5

Same as the gluteus medius muscle. It functions to abduct and medially rotate the thigh. It is innervated by the superior gluteal nerve.

Question 6

What is the innervation and action of the tensor fascia lata muscle?

Answer 6

It can flex and abduct the thigh. Assists in medial rotation of thigh and extension of the leg. Innervated by the superior gluteal nerve.

Question 7

Why is the piriformis muscle unique?

Answer 7

It passes through the greater sciatic foramen. It demarcates gluteal blood vessels and nerves.

Question 8

What is the innervation and action of the piriformis muscle?

Answer 8

Lateral rotator; nerve to the piriformis

Question 9

Why is the obturator internus unique?

Answer 9

It passes through the lesser sciatic foramen

Question 10

What is the blood supply to the obturator internus?

Answer 10

Inferior gluteal artery

Question 11

What is the innervation and action of the obturator internus muscle?

Answer 11

Lateral rotation; nerve to obturator internus

Question 12

How are the superior gemellus muscle and the inferior gemellus muscle similar? How are they different?

Answer 12

SG and IG muscle tendons both blend in with the OI muscle tendon. Both muscles insertion and action are the same as the OI muscle. However, the SI is innervated by the nerve to obturator internus and the IG is innervated by the nerve to the quadratus femoris.

Question 13

Branches of what major artery supply the gluteal region?

Answer 13

Branches of the internal iliac artery

Question 14

What are the contents of the greater sciatic foramen?

Answer 14

Inferior gluteal vessels
Internal pudendal vessels
Inferior gluteal nerve
Pudendal nerve
Sciatic nerve
Posterior femoral cutaneous nerve
Nerve to obturator internus
Nerve to quadratus femoris

Question 15

What muscle is the dividing line between the greater and lesser sciatic foramen?

Answer 15

Piriformis muscle

Question 16

What is the innervation of the gluteus maximus muscle?

Answer 16

Inferior gluteal nerve

Question 17

Positive Trendelenburg’s sign indicates damage to what lower extremity nerve?

Answer 17

Superior gluteal nerve

Question 18

What occurs in patients suffering from Duchenne’s limp?

Answer 18

Patient loses steadying action of gluteus medius and minimus

Question 19

What muscles are lateral rotators of the thigh?

Answer 19

SG m., IG m., OI m., and QF m.

Question 20

What muscle separates the superior and inferior gemelli?

Answer 20

Obturator internus m.

Question 21

What muscles are supplied by the nerve to the obturator internus?

Answer 21

Obturator internus muscle and superior gemellus

Question 22

What muscles are supplied by the nerve to the quadratus femoris?

Answer 22

Quadratus femoris muscle and inferior gemellus m.

Question 23

Where do the muscles of the “triceps coxae” insert?

Answer 23

Primarily these three muscles insert on the greater trochanter of the humerus?