Lecture 44 - Gluteal Region Flashcards
Lower limb bud levels
L2-S2
Upper limb bud levels:
C5-T1
Development of upper and lower limbs
- 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.
Structures that pass through the greater sciatic foramen:
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
Structures that pass through the lesser sciatic foramen:
a. Tendon of obturator internus
b. Internal pudendal vessels and pudendal nerve
c. Nerve to obturator internus
Superficial layer - Gluteal muscles:
gluteus maximus,
medius and minimus,
mainly extensors and abductors of thigh
Gluteus maximus m
- 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
Gluteus medius m
- 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
Gluteus minimus m
- Origin – ilium between anterior and inferior gluteal lines
- Insertion – Gr. Trochanter
- Action – Abduction and medial rotation
- Nerve – Superior gluteal
- Blood supply – Superior gluteal a
Positive Trendelenburg Sign
- –>damage to superior gluteal nerve
- Waddling gait
- High steppage gait
- Swing out gait
Deep layer muscles:
- –>Stabilizers of hip joint and lateral rotators of the thigh
- piriformis
- obturator internus
- superior gamellus
- inferior gamellus
- quadratus femoris
Piriformis m
- 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
Obturator Internus m
- 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
Superior Gemellus m
- Origin: Ischial spine
- Insertion: Tendon of obturator interns
- Nerve: Same as obturator internus
- Action: Same as obturator internus
Inferior Gemellus m
- Origin: Ischial tuberosity
- Insertion: Tendon of obturator internus
- Nerve: Same as quadrates Femoris
- Action: Same as obturator internus
Quadratus Femoris m
- Origin: Ischial tuberosity
- Insertion: Intertrochanteric crest
- Nerve: Nerve to quadratus femoris (L4, S1)
- Action: Laterally rotate thigh
All branches of the sacral plexus pass through the…
greater sciatic foramen
nerves of the sacral plexus supply
gluteal region
posterior thigh
entire leg
entire foot
L4-S4 roots of the plexus split to give
anterior and posterior divisions
Posterior division nerves
- from L4-S4 roots
- Common peroneal nerve
- Superior gluteal
- Inferior gluteal
- Posterior femoral cutaneous- partly
- Nerve to piriformis
Anterior division nerves
- from L4-S4 roots
- Tibial nerve
- N. to obturator internus
- N. to quadratus femoris
- Pudendal nerve
- N. to levator ani
Pelvic splanchnic nerves’ relationship to sacral plexus
THEY ARE NOT PART OF THE SACRAL PLEXUS
Sacral Plexus info:
- 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
S1-S4 nerves enter the pelvis through the
sacral foramina
Superior gluteal n levels and details
- ( 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
Inferior gluteal n levels and details
- (L5-S2)
- Injury to this nerve would affect gluteus maximus muscle
Sciatic n levels and details
- (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
Posterior femoral cutaneous n levels
S1-S3
Nerve to quadratus femoris levels
L4-S1
Nerve to obturator internus levels
L5-S2
Pudendal nerve levels
S2-S4
Cutaneous innervation of the gluteal region
a. Superior cluneal - dorsal primary rami
b. Medial cluneal - dorsal primary rami
c. Inferior cluneal - ventral primary rami
Superior gluteal a supplies:
- 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
Inferior gluteal a supplies:
- 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
Internal pudendal a supplies:
- Originate directly or indirectly from internal iliac artery
- Enter the gluteal region through the greater sciatic foramen
- Supplies the perineal region
Gluteal veins are:
- Tributaries of the internal iliac vein
1) Superior and inferior gluteal
2) Internal pudendal
