Pelvis And Perineum Flashcards
(24 cards)
The pelvis
The part of the trunk inferoposterior to the abdomen and is the area of transition between the trunk and the lower limbs
The pelvic cavity
A continuation of the abdominal cavity into the pelvis through the pelvic inlet
The perineal region
The area of the trunk between the thighs and buttocks extending from the pubis to the coccyx
The perineum
A shallow compartment lying deep to this area and inferior to the pelvic diaphragm
The pelvic inlet is bounded by the linea terminalis which is formed by
Superior margin of the pubic symphysis anteriorly
Posterior border of the pubic crest
Pecten pubis the continuation of the superior ramus of the pubis which forms a sharp ridge
Arcuate line of the ilium
Anterior border of the ala of the sacrum
Sacral promontory
The pelvic outlet is bounded by
Inferior margin of the pubic symphysis anteriorly
Inferior rami of the pubis and ischial tuberosities anterolaterally
Sacrotuberous ligaments posterolaterally
Tip of the coccyx posteriorly
Main functions of the pelvic girdle
Transfer weight of the upper body from the axial to the lower appendicular skeleton for standing and walking
To withstand compression and other forces resulting from its support of body weight
To house and protect the pelvic viscera
What are the three bones of the pelvic girdle
Right and left hip bones
- ilium ischium pubis
And the sacrum
The hip bones are joined where
The pubic symphysis
Sacrifices-iliac joints
Sacro-Iliac joints
Synovial joints
Limited movement tho!
Sacrotuberous and sacropinous ligaments allow some movement
Muscles of the pelvis walls and floors
Coccygeus
Obturator internus
Piriformis
Coccygeus
Superior - ischial spine
Inferior - inferior end of sacrum and coccyx
Innervation - branches of s4 and s5 nerves
Action - forms small part of pelvic diaphragm that supports pelvic viscera
Flexes coccyx
Obturator internus
Superior - pelvic surface of ilium and ischium obturator membrane
Inferior - greater trochanter of femur
Innervation - nerve to obturator internus (L5,s1,s2)
Action - laterally rotates hip joint assists in holding head of femur in acetabulum
Piriformis
Superior - pelvic surface of 2-4 sacral segments superior margin of greater sciatic notch and sacrotuberous ligament
Inferior - greater trochanter of femur
Innervation - anterior rami of s1 and s2
Action - laterally rotates hip joint abducts hip joint assists in holding head of femur in acetabulum
6 nerves of sacral and coccygeal plexuses
Sciatic
Superior gluteal
Inferior gluteal
Nerve to piriformis
Nerve to quadratus femoris and inferior gemellus
Nerve to obturator internus and superior gemellus
Sciatic nerve distribution
Articular branches to hip joint and muscular branches to flexors or knee and all muscles in leg and foot
Superior gluteal nerve distribution
Gluteus medius gluteal minimus and tensor fasciae latae muscles
Inferior gluteal nerve distribution
Gluteus Maximus muscle
Never to piriformis distribution
Piriformis muscle
Nerve to quadratus femoris and inferior gemellus distribution
Quadratus femoris and inferior gamellus muscles
Nerve to obturator internus and superior gamellus distribution
Obturator internus and superior gemellus muscles
Sacrococcygeal joint
Secondary cartilaginous joint
Join the apex of the sacrum to the base of the coccyx
Sacrococcygeal ligaments
Long strands that reinforce the joint (sacrococcygeal)
Lumbosacral joints
Lumbosacral ligaments
Intervertebral joint Zygapophysial joint (facet joints)
Iliolumbar ligaments unite the transverse process of L5 to the ilia
