Exam #5: Gluteal Region Flashcards
When do the lower limb buds first appear, and where?
- 5th week of development
- L2-S2
How are the toes & soles of the feet initially oriented in the limb bud?
- Great toes are superior
- Soles are directed medially
When do the lower limb buds rotate?
7th week of development
What direction do the lower limb buds rotate? How does this compare to the upper limb buds?
- Lower limb buds rotate medially
- Upper limb buds rotate laterally
What are the three parts of the hip bone?
Ilium
Ischium
Pubis
*Note that the three parts fuse at the end of the teenage years & each contains its own ossification center.
What does the hip bone articulate with?
Sacrum & the femur
*This is where the axial & appendicular skeleton join
What is the pelvic girdle?
2 hip bones together
What is the bony pelvis?
Pelvic girdle
Sacrum
Coccyx
All bound together by ligaments
Where do the gluteal muscles & iliacus attach?
Both attach to the “ala” or wing of the ilium
- Gluteal muscles attach laterally
- Iliacus attaches medially
What is the iliac fossa?
Concavity of the ala
What part of the acetabulum does the ilium form?
Superior 2/5
What vertebral structure is the iliac crest directly in line with?
L4-5 disc
What is the posterior inferior iliac spine the attachment site for?
Posterior sacroiliac ligament
How much of the acetabulum does the ischium contribute?
2/5
What four structures are part of the body of the ischium?
Ischial tuberosity
Ischial spine
Lesser sciatic notch
Greater sciatic notch
What forms the ischiopubic ramus?
Ischial ramus joins with the inferior ramus of the pubis to form the ischiopubic ramus
How much of the acetabulum does the pubis contribute?
1/5
What three structures are part of the body of the pubis?
Symphysis pubis
Pubic crest
Pubic tubercle
What part of the pubis joins with the ilium & ischium?
The superior ramus of the pubis fuses with the ilium & ischium within the acetabulum
What structure is part of the inferior ramus of the pubis?
Obturator foramen
What is the greater sciatic foramen?
Passageway for all lower limb nerves & arteries to leave the pelvis
What forms the greater sciatic foramen?
Greater sciatic notch
Sacrospinous ligament
Sacrotuberous ligament
List the structures that pass through the greater sciatic foramen (7).
1) Piriformis muscle
2) Superior & inferior gluteal vessels/ nerves
3) Internal pudendal vessels & pudendal nerve
4) Sciatic nerve
5) Posterior femoral cutaneous nerve
6) Nerve to guadratus femoris & inferior gemellus
7) Nerve to obtruator internus & superior gemellus
What forms the lesser sciatic foramen?
Less sciatic notch
Sacrospinous ligament
Sacrotuberous ligament
What structures pass through the lesser sciatic foramen?
1) Tendon of obturator internus
2) Internal pudenal vessels & pudendal nerve
3) Nerve to the obturator internus
What muscles form the superficial layer of gluteal muscles?
Gluteus maximus
Gluteus medius
Gluteus minimus
What muscles form the deep layer of gluteal muscles?
Piriformis Obtruator Internus Superior Gemellus Inferior Gemellus Quadratus Femoris
What is the origin of the gluteus maximus?
1) Sacrotuberous ligament
2) Ilium
3) Sacrum
4) Coccyx
What is the insertion of the gluteus maximus?
1) Gluteal tuberosity
2) Iliotibial tract
What is the function of the gluteus maximus?
Extension & lateral rotation of the thigh
*Note that this most is used in rising from a sitting position & running
What nerve innervates the gluteus maximus?
Inferior gluteal
What arteries supply the gluteus maximus?
Superior & inferior gluteal arteries
What is the origin of the gluteus medius?
Ilium between the anterior & posterior gluteal line
What is the insertion of the gluteus medius?
Greater trochanter of the femur
What is the action of the gluteus medius?
1) ABduction & medial rotation of the thigh
2) With the gluteus minimus, stops hip from sagging on unsupported side
What nerve innervates the gluteus medius?
Superior gluteal
What artery supplies the gluteus medius?
Superior gluteal artery
What is the origin of the gluteus minimus?
Ilium between the anterior & inferior gluteal lines
What is the insertion of the gluteus minimus?
Greater trochanter of the femur
What is the action of the gluteus minimus?
ABduction & medial rotation of the thigh
What nerve innervates the gluteus minimus?
Superior gluteal nerve
What artery supplies the gluteus minimus?
Superior gluteal artery
What does a positive Trendelenburg Sign indicate?
Damage to the superior gluteal nerve
What is the origin of the piriformis?
Anterior surface of the sacrum
What is the insertion of the piriformis?
Greater trochanter of the femur
What nerves innervate the piriformis?
S1 & S2
What is the function of the piriformis?
Lateral rotation of the thigh
What is the origin of the Obturator Internus?
Obtruator membrane & surrounding bone
What is the insertion of the Obturator Internus?
Greater trochanter of the femur
What nerves innervate the Obtruator Internus?
L5, S1, & S2
What is the function of the Obtruator Internus?
1) Lateral rotation
2) Extension
3) Abduction of flexed thigh
What is the origin of the superior gemellus?
Ischial spine
What is the insertion of the superior gemellus?
Tendon of the obtruator internus
What nerve innervates the superior gemellus?
Nerve to the obtruator internus, L5, S1, & S2
What is the action of the superior gemellus?
Same as the obtruator internus
1) Lateral rotation
2) Extension
3) Abduction of flexed thigh
What is the origin of the inferior gemellus?
Ischial tuberosity
Where does the inferior gemellus insert?
Tendon of the obturator internus
What nerve innervates the inferior gemellus?
Same as the quadratus femoris
L5 & S1
What is the action of the inferior gemellus?
Same as the obtruator internus
1) Lateral rotation
2) Extension
3) Abduction of flexed thigh
Where is the origin of the quadratus femoris?
Ischial tuberosity
Where does the quadratus femoris insert?
Intertrochanteric crest
What nerve innervates the quadratus femoris?
Nerve to the quadratus femoris (L5 & S1)
What is the function of the quadratus femoris?
Lateral rotation of the thigh
What does the term “hip fracture” most commonly refer to?
Fractures of the femoral head, neck, or trochanter