sacrum and gluteal region: osteology

the hip, knee, and ankle joints are all in line with what?

our natural COG

this structure is also called the pilondial dimple and is a common area for cysts

sacral dimple

what is another name(s) for intergluteal cleft?

natal cleft or gluteal crease

what is another name for the ischial tuberosity?

gluteal fold

what are the 3 main functions of the posterior pelvis?

support and enclose viscera, transfers and distributes weight of trunk to lower limbs, and creates attachment sites for muscles and ligs

this sacral structure is formed by the anterior lip of S1

sacral promontory

how many sacral vertebrae do we have?

5 fused

this structure is a continuation of the vertebral canal

sacral canal

this sacral structure is on each side of the sacrum and meets with the ilium (ear shaped)

auricular surface

this structure is also known as the spine of the sacrum

median sacral crest

the ASIS and PSIS are located on what bone?

ilium

what bone do we sit on?

ischium

name the 3 parts of the pubis

sup and inf pubic ramus, body

what 3 bones form the acetabulum?

ilium, ischium, pubis

the sacroiliac jt has cartilage on the sacral side and __ on the ilium side

hyaline, fibrocartilage

what is the purpose of the sacroiliac jt?

meant for weight distribution rather than mobility

what two bones make up the sacroiliac jt?

sacrum and ilium

what type of jt is the pubic symphysis?

cartilaginous?

what structure lies inside the pubic symphysis?

fibrocartilaginous disc

is the pubic symphysis imobile?

yes

this ligament supports the sacrum anteriorly

ant longitudinal lig

what vertebrae does the lumbosacral jt lie between?

L5 and S1

where is the ant sacroiliac lig located?

between the sacrum and ilium

what are the 2 post sacroiliac ligs?

short and long

this ligament is weak and can be a common source of pain

ant sacroiliac lig

this ligament is located under the post short sacroiliac lig and is the strongest post sacral lig

sacral interosseous lig

what movements does the sacral interosseous lig resist?

ant and inf movements

the sacrotuberous ligament is divided into

3 large bands

what is the purpose of the sacrotuberous lig?

stabilizes sacrum against mutation (forward tilt/rocking) and stops sacrum from moving post and inf

this ligament is located under the sacrotuberous ligament

sacrospinous lig

this ligament has 3 heads, is thin, and is shaped like a triangle

sacrospinous

what is the purpose of the sacrospinous lig?

stablizes sacrum and resists post and inf movements

this is a thick structure that covers the gluteus maximus

superficial fascia

what is embedded in the superficial fascia of the glutes?

cutaneous neurovasculature

name the 3 lesser sciatic foramen contents

internal pudendal vessels, pudendal nerve, and tendon of obturator internus

name the 3 vessel groups that are contents of the greater sciatic foramen

superior gluteal vessels, inferior gluteal vessels, and internal pudendal vessels

name the 3 nerves that are contents of the greater sciatic foramen

sciatic, rudendal, and post femoral cutaneous

what muscle is a part of the greater sciatic foramen

piriformis