10.1 Gluteal Region

Question 1

Identify the gluteus maximus muscle, it’s attachments, innervation, and function.

Answer 1

• Attaches proximally to the posterior ilium, posterior gluteal line, dorsal sacrum, dorsal coccyx, sacrotuberous ligament; Distally, iliotibial tract
• Innervated by Inferior gluteal n (L5-S2)
• Fxn: extension of thigh, lateral rotation of thigh; steadies thigh and assists in rising from sitting position

Question 2

Identify the gluteus medius and minimus muscles, their attachments, innervation, and function.

Answer 2

• Attach from ilium to greater trochanter of femur.
• Innervated by superior gluteal n. (L4-S1)
• Fxn: Abduction of the femur. Also rotation.

Question 3

Identify the piriformis muscle, it’s attachments, innervation, and function.

Answer 3

• originates from the pelvic surface of the sacrum and inserts onto the apex of the greater trochanter of the femur
• Innervated by anterior rami of Sacral plexus (S1-S2).
• Fxn: externally rotate, abduct, and extend the femur at the hip joint. It also acts to stabilize the hip joint.

Question 4

Identify the superior gluteal a. v. and n.
Describe the course of this bundle.
From what proximal artery does this branch?
Into what vein dos this drain?
What is the root of this nerve?

Answer 4

• Emerges superior to the piriformis muscle
• Artery is branch off posterior Internal iliac a.
• Vein drains into Internal iliac v.
• Nerve root L4-S1

Question 5

Identify the inferior gluteal a. v. and n.
Describe the course of this bundle.
From what proximal artery does this branch?
Into what vein dos this drain?
What is the root of this nerve?

Answer 5

• Emerges inferior to piriformis muscle.
• Artery is branch off anterior internal iliac a.
• Vein drains into internal iliac v.
• Nerve root L5-S2

Question 6

Identify the sciatic nerve. From what spinal level does this branch?
Describe its course.

Answer 6

L4-S3

Exits pelvis beneath piriformis and through greater sciatic foramen, travels down posterior lower limb.

Question 7

Identify the posterior femoral cutaneous nerve.
From what nerve does this branch?
Describe its course.

Answer 7

• emerging from the pelvis inferior to the piriformis, medial to the sciatic nerve.
• S1-S3
• Gives off several cutaneous branches to skin of gluteal region, perineum, back of thigh.

Question 8

Identify the Obturator internus tendon

Answer 8

• originates from the inner surface of the obturator membrane and its bony boundaries and inserts onto the medial surface of the greater trochanter of the femur.
• Innervation: n. to obturator internus (L5-S2)
• Fxn: externally rotate and extend the femur at the hip joint. It also acts to abduct or adduct the femur at the hip joint depending on the position of the joint.

Question 9

Identify the superior and inferior gemellus mm. their attachments, innervation, and function.

Answer 9

Superior: originates from the ischial spine and inserts onto the medial surface of the greater trochanter of the femur.

Inferior: originates from the ischial tuberosity and inserts onto the medial surface of the greater trochanter of the femur.

Innervation: : n. to obturator internus (L5-S2) innervates superior gemellus, n. to quadratus femoris innervates inferior gemellus

Fxn: acts to externally rotate and extend the femur at the hip joint. It also acts to abduct or adduct the femur at the hip joint depending on the position of the joint.

Question 10

Identify the quadratus femoris muscle, it’s attachments, innervation, and function.

Answer 10

• Originates from the lateral border of the ischial tuberosity and inserts onto the intertrochanteric crest of the femur.
• Innervation: n. to quadratus femoris (L4-S1)
• Fxn: externally rotate and extend the femur at the hip joint.

Question 11

Identify the sacrotuberous ligament and its attachments.

Answer 11

Sacrum to ischial tuberosity

Question 12

Identify the sacrospinous ligament and its attachments.

Answer 12

Sacrum to ischial spine

Question 13

Identify the internal pudendal a. v. and and n. Describe their course.
From what proximal artery does this branch?
Spinal root?

Answer 13

• They exit the pelvis via the greater sciatic foramen, cross under the sacrospinous ligament (which attaches to the ischial spine), and enter the perineal region via the lesser sciatic foramen.
• Internal pudendal a. from terminal branch of anterior iliac a.
• Pudendal Nerve: S2-S4