Pelvis Flashcards
Pelvic Girdle consists of …
2 hip bones united anteriorly at the symphysis pubis and posteriorly at the sacrum through the sacroiliac joints
Purpose of the pelvic girdle is …
to provide strong stable support for vertebral column/pelvic and lower abdominal contents, connects lower limbs to axial skeleton, offers a greater degree of strength and lesser degree of mobility
3 bones the pelvic girdle consists of
Ilium (superiorly), Pubis (anteriorly & inferiorly), Ischium (posteriorly & inferiorly) - all fuse together at around 23 yrs
Describe the ilium - 3 points
largest of the 3 components, has ALA (wing) superiorly & body inferiorly, body forms part of the acetabulum
acetabulum articulates with …
head of the femur
Describe the iliac crest and the iliac spine
iliac crest is the superior border of the ilium and it projects anteriorly and ends at the anterior superior iliac spine (ASIS), the anterior inferior iliac spine (AIIS) sits inferiorly to the ASIS, iliac crest projects posteriorly finishing at the posterior superior iliac spine (PSIS), the posterior inferior iliac spine (PIIS) sits inferior to the PSIS
Describe the ischium - 2 points
the inferior and posterior portion of the hip bone, has superior body & inferior ramus which fuses with the pubis
what 3 things does the ischium have
ischial spine, lesser sciatic notch below the spine, ischial tuberoscity
the ischium and pubis surround the …
obturator formamen, covered by fibrous obturator membrane but vessels and nerves still pass through it
Describe the pubis - 2 points
the anterior inferior portion, made up of a superior rams inferior ramus and a body between them
Pubic tubercle projects …
anteriorly and superiorly from pubis
Pubic symphysis is …
where the 2 pubic bones meet, separated by a disco of fibro-cartilage, during childbirth hormones act on the pubic symphysis allowing it to relax and aid delivery
Describe the acetabulum - 4 points
a deep fossa formed by ilium, ischium and pubis, inferior aspect is the acetabular notch, this forms a foramen through which blood vessels and nerves pass, a point of attachment for ligaments of ball and socket hip joint
Bony pelvis is divided into …
superior/inferior portions by pelvic brim, portion above = greater (false) pelvis, portion below = lesser (true) pelvis
Describe the line drawn to divide the pelvis into true/false
a line from the sacral promontory, laterally and inferiorly along the lines of the ilium, and then along the superior aspect of the pubis
What does the false pelvis house
no pelvic organs, only the urinary bladder when its full, uterus/ovaries/uterine tubes of female
The true pelvis has a …
pelvic inlet, pelvic outlet, cavity
The true pelvis is bound by …
sacrum/coccyx posteriorly, ilium/ischium laterally, pubis anteriorly
The superior & inferior borders of the true pelvis are …
superior opening is bordered by the pelvic brim = pelvic inlet, inferior opening is bordered by the pelvic outlet
Differences between the male and the female pelvis - 5 points
male = pelvic brim is smaller/heart shaped, heavier, acetabulum is largely and more lateral, obturator formamen is more round, pubic arch is less than 90 degrees female = pelvic brim is larger/more oval, lighter, acetabulum is small and anterior, obturator formate is more oval, pubic arch is greater than 90 degrees
Describe the sacrum - 4 points
triangular, formed by union of 5 sacral vertebrae - fusion begins at 18 completed by 30, found posteriorly, articulates with iliac bones at scare-iliac joints (SIJ)
The female sacrum is …
shorter, wider, more curved between S2-S3
Describe what the sacrum faces and the sacrums posterior crests- 3 points
and its transverse lines/processes - 3 points
concave anterior side faces pelvic cavity, convex posterior surface contains medial sacral crest which is fused upper spinous processes of sacral vertebrae, lateral sacral crest = fusion of transverse processes,
contains 4 transverse lines/ridges which mark the fusion of vertebrae, at the ends of these lines are anterior sacral foramina, fused transverse processes of S1 form the sacral ala
Describe the posterior sacral foramina - 3 points
4 pairs, connect with anterior sacral foramina, transmit nerves & blood vessels
Describe the sacral canal and the 5th sacral vertebrae
Sacral canal is a continuation of the vertebral canal
The 5th sacral vertebrae attach to the coccyx by ligaments
Apex of the sacrum is …
the narrow inferior portion
Base of the sacrum is …
the broader superior portion
Sacral promontory is …
the anteriorly projecting border
Auricular surface of the sacrum is …
ear-shaped, lateral, allows articulation with iliac bones at SIJ
Describe the articulation between S1 and L5 - 2 points
superior articular process of S1 articulates with inferior articular process of L5 - base of sacrum articulates with body of L5 forming limbo-sacral joint
Describe the coccyx - 3 points
triangular, fusion of 4 coccygeal vertebrae, foramina on the lateral aspect
Purpose of the coccyx and its articulations - 2 points
useful for ligament and tendon attachment, articulates superiorly with sacrum
Difference between male and female coccyx
males = points anteriorly females = moves inferiorly - childbirth
