Lecture 44 - Gluteal Region

Question 1

Lower limb bud levels

Answer 1

L2-S2

Question 2

Upper limb bud levels:

Answer 2

C5-T1

Question 3

Development of upper and lower limbs

Answer 3

• The great toes of the lower limbs (thumbs of upper limb) are located on the superior aspect of the buds
• The soles (palms of the upper limb) are directed medially
• Both limbs undergo torsion around their long axis but in the opposite direction – during the 7th week
• The lower limbs rotate medially and the upper limbs rotate laterally about 90 degrees around their long axis
• This rotation of the limbs is still in progress even after birth.

Question 4

Structures that pass through the greater sciatic foramen:

Answer 4

a. Piriformis muscle
b. Superior and inferior gluteal vessels and nerves
c. Internal pudendal vessels and pudendal nerve
d. Sciatic nerve
e. Posterior femoral cutaneous nerve
f. Nerve to quadratus femoris and inferior gemellus
g. Nerve to obturator internus and superior gemellus

Question 5

Structures that pass through the lesser sciatic foramen:

Answer 5

a. Tendon of obturator internus
b. Internal pudendal vessels and pudendal nerve
c. Nerve to obturator internus

Question 6

Superficial layer - Gluteal muscles:

Answer 6

gluteus maximus,
medius and minimus,
mainly extensors and abductors of thigh

Question 7

Gluteus maximus m

Answer 7

• Origin – sacrotuberous ligament, ilium (posterior to posterior gluteal line), sacrum and coccyx
• Insertion – gluteal tuberosity and iliotibial tract
• Action – Extend and lateral rotate thigh; Rising from sitting position; Running
• Nerve – Inferior gluteal
• Blood vessels – Superior and inferior gluteal arteries

Question 8

Gluteus medius m

Answer 8

• Origin – ilium between anterior and posterior gluteal line
• Insertion – Gr. Trochanter
• Action – Abduction and medial rotation of thigh; Along with gluteus minimus stops hip from sagging on the unsupported side
• Nerve – Superior gluteal
• Blood vessel – Superior gluteal artery

Question 9

Gluteus minimus m

Answer 9

• Origin – ilium between anterior and inferior gluteal lines
• Insertion – Gr. Trochanter
• Action – Abduction and medial rotation
• Nerve – Superior gluteal
• Blood supply – Superior gluteal a

Question 10

Positive Trendelenburg Sign

Answer 10

• –>damage to superior gluteal nerve
• Waddling gait
• High steppage gait
• Swing out gait

Question 11

Deep layer muscles:

Answer 11

• –>Stabilizers of hip joint and lateral rotators of the thigh
• piriformis
• obturator internus
• superior gamellus
• inferior gamellus
• quadratus femoris

Question 12

Piriformis m

Answer 12

• Origin: Anterior surface of sacrum (inside the pelvis)
• Insertion: Greater Trochanter; Located partly in the pelvis and partly in the gluteal region
• Nerve: S1, S2
• Action: Lateral rotation of thigh

Question 13

Obturator Internus m

Answer 13

• Origin: obturator membrane and surrounding bone
• Insertion: Greater Trochanter; Leaves pelvis through the lesser sciatic foramen
• Nerve: Nerve to obturator internus (L5-S2)
• Action: Lateral rotation, extension, and abduction of flexed thigh

Question 14

Superior Gemellus m

Answer 14

• Origin: Ischial spine
• Insertion: Tendon of obturator interns
• Nerve: Same as obturator internus
• Action: Same as obturator internus

Question 15

Inferior Gemellus m

Answer 15

• Origin: Ischial tuberosity
• Insertion: Tendon of obturator internus
• Nerve: Same as quadrates Femoris
• Action: Same as obturator internus

Question 16

Quadratus Femoris m

Answer 16

• Origin: Ischial tuberosity
• Insertion: Intertrochanteric crest
• Nerve: Nerve to quadratus femoris (L4, S1)
• Action: Laterally rotate thigh

Question 17

All branches of the sacral plexus pass through the…

Answer 17

greater sciatic foramen

Question 18

nerves of the sacral plexus supply

Answer 18

gluteal region
posterior thigh
entire leg
entire foot

Question 19

L4-S4 roots of the plexus split to give

Answer 19

anterior and posterior divisions

Question 20

Posterior division nerves

Answer 20

• from L4-S4 roots
• Common peroneal nerve
• Superior gluteal
• Inferior gluteal
• Posterior femoral cutaneous- partly
• Nerve to piriformis

Question 21

Anterior division nerves

Answer 21

• from L4-S4 roots
• Tibial nerve
• N. to obturator internus
• N. to quadratus femoris
• Pudendal nerve
• N. to levator ani

Question 22

Pelvic splanchnic nerves’ relationship to sacral plexus

Answer 22

THEY ARE NOT PART OF THE SACRAL PLEXUS

Question 23

Sacral Plexus info:

Answer 23

• Lower part of lumbosacral plexus – the nerve plexus of lower limbs
• The plexus as a whole is covered by branches of the internal iliac artery
• The major part of the plexus lies on the anterior surface of the piriformis muscle

Question 24

S1-S4 nerves enter the pelvis through the

Answer 24

sacral foramina

Question 25

Superior gluteal n levels and details

Answer 25

- ( L4-S1) - Exits through the greater sciatic foramen above the piriformis muscle - All the other branches of the sacral plexus that leave the pelvis do so below the piriformis muscle - Injury to superior gluteal nerve would affect the gluteus medius and minimus and tensor fasciae latae muscles

Question 26

Inferior gluteal n levels and details

Answer 26

- (L5-S2) | - Injury to this nerve would affect gluteus maximus muscle

Question 27

Sciatic n levels and details

Answer 27

- (L4-S3) - Largest branch of the sacral plexus - Consist of two nerves: a. Tibial – anterior division(L4-S3) b. Common Peroneal –posterior division(L4-S2) - Injury to sciatic nerve - Will not affect any muscles in the gluteal region

Question 28

Posterior femoral cutaneous n levels

Answer 28

S1-S3

Question 29

Nerve to quadratus femoris levels

Answer 29

L4-S1

Question 30

Nerve to obturator internus levels

Answer 30

L5-S2

Question 31

Pudendal nerve levels

Answer 31

S2-S4

Question 32

Cutaneous innervation of the gluteal region

Answer 32

a. Superior cluneal - dorsal primary rami b. Medial cluneal - dorsal primary rami c. Inferior cluneal - ventral primary rami

Question 33

Superior gluteal a supplies:

Answer 33

- Originate directly or indirectly from internal iliac artery - Enter the gluteal region through the greater sciatic foramen - Supply Gluteus Maximus, medius and minimus and tensor fasciae latae

Question 34

Inferior gluteal a supplies:

Answer 34

- Originate directly or indirectly from internal iliac artery - Enter the gluteal region through the greater sciatic foramen - Supply gluteus maximus and the short lateral rotators of thigh

Question 35

Internal pudendal a supplies:

Answer 35

- Originate directly or indirectly from internal iliac artery - Enter the gluteal region through the greater sciatic foramen - Supplies the perineal region

Question 36

Gluteal veins are:

Answer 36

- Tributaries of the internal iliac vein 1) Superior and inferior gluteal 2) Internal pudendal