Abdomen, Pelvis, Perineum 4 DR Flashcards
what is the pelvic girdle
what is the function of the pelvic girdle
primary functions:
bear the weight of upper body when sitting + standing
transfer the weight of body from axial to lower appendicular skeleton for standing + walking
provide attachment for muscles of locomotion, posture and abdominal wall muscles → needs to be able to withstand the force generated by their actions → pelvic girdle is strong and rigid
other functions:
contain and protect pelvic viscera (inferior parts of urinary tract + reproductive organs) and inferior abdominal viscera (intestines) whilst permitting the passage of their terminal parts (and fetus) via perineum
support abdominopelvic viscera and pregnant uterus
provide attachemnt for erectile bodies of external genitalia
provide attachment for muscles + membranes that form the pelvic floor
what bones make up the pelvic girdle
3 bones in adults
right and left hip bones - made up of ilium, ischium, pubis fused together
sacrum - formed by fusion of 5 originally separate vertebrae
where do each of the bones begin and end in pelvic girdle
what are the palpable landmarks of the iliac bone
what are the joints which make up the pelvic girdle
right and left hip bones joined by pubic symphysis (fibrocartilaginous)
right and left hip bones join with sacrum at sacro-iliac joint (synovial)
what are the different parts of the ilium
what are the different parts of the ischium
what are the different parts of the pubis
how is the pelvis divided
greater and lesser
separated by pelvic inlet (bony edges of pelvic inlet = pelvic brim)
what is the pelvic brim
what forms it
what is the pelvic brim
what are the borders of it
greater and lesser
separated by pelvic inlet (bony edges of pelvic inlet = pelvic brim)
what is the difference between the pelvic inlet and outlet
what are the borders of the pelvic outlet
where is the greater/false pelvis
what are its borders
what does it contain
where is the lesser/true pelvis
what are its borders
what does it contain
how does the true pelvic cavity relate to the perineum
describe the orientation of the pelvic girdle
what is the sacral promontory
what is the sciatic notch
what are the differences between the male and female pelvis
female pelvis is:
wider and broader but lighter in weight
oval shaped pelvic inlet compared to heart shaped in men
less prominent ischial spines → greater bispinous diameter
larger angle of sub-pubic arch
shorter more curved sacrum + less pronounced sacral promontory
what are the differences between the male and female pelvis
female pelvis is:
wider and broader but lighter in weight
oval shaped pelvic inlet compared to heart shaped in men
less prominent ischial spines → greater bispinous diameter
larger angle of sub-pubic arch
shorter more curved sacrum + less pronounced sacral promontory
what are the primary joints of the pelvic girdle
what is their function
sacroiliac joints
pubic symphysis
other joints - sacrococcygeal and lumbosacral joint
all supported + strengthened by ligaments
what is the significance of the sacral-iliac joints
how are they unique compared to other similar joints
connect the axial skeleton to the inferior appendicular skeleton - transmits weight from vertebral column to hip bone
synovial joint but has much more limited mobility compared to other synovial joints → because they have to transmit so much bodyweight onto hip bones
what ligaments support the sacro-iliac joints
where do they attach
anterior sacro-iliac ligament - thin ligament between sacrum and iliac joint
posterior sacro-iliac ligament -
interosseous sacro-iliac ligament
sacrospinous ligament - between sacrum and ischial spine
sacrotuberous ligament - between sacrum and ischial tuberosity
sacrospinous ligament is anterior and medial to sacrotuberous
how is the sciatic notch divided
divided by sacrospinous and sacrotuberous ligaments (which stabilise sacro-iliac joint) into greater and lesser sciatic foramen
what is the structure of the pubic symphysis
fibrocartilaginous interpubic disc between the bodies of the pubic bones
supported by ligaments
how does the pubic symphysis vary between sexes
interpubic disc is generally wider in women
what ligaments support the pubic symphysis
superior pubic ligament
inferior pubic ligament
decussating fibres of tendinous attachment of rectus abdominis and external oblique also strengthen pubic symphysis anteriorly
what are the lumbosacral joints
articulations between L5 and S1
intervertebral joint - formed by intervertebral disc between their bodies
joints between inferior articular processes of L5 and facets of S1
strengthened by fan-like iliolumbar ligaments radiating from from transverse processes of L5 to ilia
what is the sacrococcygeal joint
joint between apex of sacrum and base of coccyx - fibrocartilaginous
stabilised by anterior and posterior sacrococcygeal ligaments
which parts of the abdominopelvic cavity are the best protected
why
superior - protected by ribcage
inferior - protected by pelvis
what part of the abdominopelvic cavity is the pelvic cavity
what does the pelvic cavity contain
funnel shaped
inferior and posterior section
pelvic viscera:
terminal parts of ureter
bladder
genital organs
blood vessels, lymphatics, nerves
“overflow” abdominal viscera:
loops of small intestine - mainly ileum
loops of large intestine - appendix and transverse and/or sigmoid colon
what are the borders of the pelvic cavity
inferior border - pelvic diaphragm (group of muscles + their fascia)
superior border - pelvic inlet
anteroinferior wall - pubic symphisis and pubis bones
lateral walls - right and left hip bones + obturator internus
posterior wall - inferiormost/apex part of sacrum + coccyx + piriformis
superior part of sacrum forms posterior-superior wall of pelvic cavity
what is important to note about the inferior border of the pelvic cavity
what is the significance of the pelvic floor attachments
they attach in the pelvic cavity (above the pelvic outlet), but descends below the pelvic outlet → forms bowl like floor to the cavity
