Anatomy of the pelvis Flashcards
what is the pelvis made up of
Right hip bone
Left hip bone
Sacrum
the pelvis is joined together too…
Joined together to form a continuous bony ring
what are the two joints within the pelvis
Joined at the sacroiliac joint posterior and pubic symphysis anteriorly
what kind of joint is the sacroiliac joint
partially cartilaginous and partially synovial,
what kind of joint is the pubic symphysis
cartilaginous
what is the hip bone made out of
Illium
Ischium
Pubis
where do the ilium, ischium and pubis all meet
acetabulum
what are in vertical alignment with each other in the bony pelvis
The ASIS and pubic symphysis
describe what makes up the ileum
Iliac crest
Posterior superior iliac spine
Anterior superior iliac spine – inguinal ligament and satrious
Anterior inferior iliac spine – attachment for rectus femoris
what muscles attaches to the anterior superior lilac spine
– inguinal ligament and satrious
what muscles attach to the anterior inferior iliac spine
attachment for rectus femoris
what makes up the pubis
Pubic tubercle
Inferior pubic ramus
Superior pubic ramus
what bones form the obturator foramen
pubic bone and ischium
the obturator Forman is mainly made up of…
obturator membrane
what is the ischium made up of
Made up of ischial spine and ischial tuberosity
what muscle attaches to the ischial tuberosity
hamstrings attach here
what is the entrance and exit point to the bony pelvis called
Bony pelvis has an pelvic inlet and a pelvic outlet
describe what the pelvic inlet and outlet is in relation to
These are describe in relation to any structure that passes through the pelvis
It first enters the pelvic inlet and then enters the pelvic outlet
describe the pelvic inlet
extends from the top of the sacrum and round, extends along the ileum and the pubis towards the pubic symphysis and then back around
describe the pelvic outlet
this is coccyx posteriorly extends towards the ischial tuberosity and pubic symphysis then back to the ischal tuberitiy and cocylx
what is the area between the pelvic inlet and outlet referred to as
true/lesser pelvis
what does the true pelvis contain
all of the pelvic organs such as the bladder, uterus and rectum are found within the true pelvis
what is above the pelvic inlet
Above the pelvic inlet you are in the abdominal cavity so there are abdominal organs within this area this is called the greater or false pelvis
describe the structure of the female pelvis
Wide sub-pubic angle (greater than 80°)- allow baby out
Wide pelvic inlet and outlet if the baby goes through he pelvis inlet it needs to go out of the pelvic outlet
Thin and light structure
describe the structure of the male pelvis
Narrow sub-pubic angle (less than 70°)
Narrow pelvic inlet and outlet, pelvic inlet is larger than pelvic outlet
Thick and heavy structure - thicker muscles attach here
what is the narrowest part of the pelvic inlet
Between the sacral promontory and the pubic symphysis is usually the narrowest part of the pelvic inlet
- this is a fixed distance
what is the narrowest part of the pelvic outlet
Interspinous distance is usually the narrowest part of the pelvic outlet the babies head will have to pass through
Not a fixed distance
what are the 4 different shapes of the female pelvis
Android
antropod
gynecoid
platypelloid
describe the 4 different shapes of the female pelvis
Android – this has more of a heart shaped pelvic inlet and wide pelvic outlook
Antropod – less common oval pelvic inlet don’t correspond that well to the hsape of the babies head
Gynecoid – most common – round pelvic inlet and round pelvic outlet, this is the ideal shape for child bearing
Platypelloid – less common, oval pelvic inlet don’t correspond that well to the hsape of the babies head
not everyone has the same shape….
Not everyone has the same shape pelvis come in a wide variety of shape and sizes
what are the ligaments of the pelvis
Sacroiliac
Inguinal
Sacrotuberous
Sacrospinous
what does the sacroiliac joint do
crosses the sacroiliac joint, very strong ligament that resists any movement that occurs there and therefore stabilises the joint
describe how relaxin acts on the sacroiliac joint
During pregnancy a hormone called relaxin causes the ligaments to relax this permits a 10-15% increase in pelvic diameter,
however you get a weakening of the sacroiliac joints and more movement occurs at these joints, this is one of the factors that contribute towards getting an increase lumbar lordosis
what is the inguinal ligament too and from
ASIS from pubic tubercle
what goes through he inguinal ligament
Femoral artery
Femoral nerve
Femoral vein
describe the obturator membrane
The obturator membrane almost completely closes off the obturator foramen.
Superiorly there is a deficiency in the membrane which creates a passageway.
what goes through the obturator foramen
Obturator artery
Obturator nerve
Obturator vein
where is the sacrospinous ligament to and from
sacrum to ischium spine
where is the sacrotuberous ligament to and from
ischial tuberosity to sacrum
what makes up the greater sciatic foramen
Sacropsinous ligament and bony pelvis
what makes up the lesser sciatic foramen
sacrospinous ligament and sacrotuberous ligament
what leaves the greater sciatic foramen
Gluteal arteries Gluteal veins Gluteal nerves Sciatic nerve Pudendal nerve Internal pudendal artery
what leaves the lesser sciatic foramen
Pudendal nerve
Internal pudendal artery
what spinal segments does the pudendal nerve stem from
S2-S4 (SOMATIC)
describe the root of the pudendal nerve
Leaves the pelvis via the greater sciatic foramen
Enters the perineum through the lesser sciatic foramen
what does the pudendal nerve supply
Provides motor and sensory innervation to the perineum
what are the four main branches of the internal iliac that leave the bony pelvis
Sueprior gluteal artery
Inferior gluteal artery
obturator artery
Internal pudendal artery – passes out of the greater sciatic foramen and passes back in to the lesser sciatic foramen
the arteries that stay in the pelvis from the internal iliac artery vary between..
men and women
what are the three female internal iliac arteries that stay in the pelvis
Artery that supply the bladder these re the superior vesicular arteries – multiple vesicular branches that all go into the top of the bladder
Then you have the uterine artery – supplies the uterus, this gives of the vaginal artery as the branch which supplies the vagina
The third and final branch is the middle rectal artery which goes towards the rectum
what are the three male internal iliac arteries that stay in the pelvis
Superiror vesicular arteries – supplies the bladder
Also have an inferior vesicular artery this runs toward the inferior aspect of the bladder and supplies the prostate gland
Middle rectal artery this goes towards the rectum
what is the pelvic floor
There is a space inferiorly in the bony pelvis but you cannot just have a space otherwise everything will fall out this is closed of by a muscular sheath called the pelvic floror
what are the muscles that make up the pelvic floor
levator ani and coccygeus
what are the three muscles of levator ani
Puborectalis
Pubococcygeus
Illeococygenous
Behind puborectalis is the pubococcygeus
Behind pubococygeous is ileococygeus
describe where the muscles of levator ani go
Go from the pubic bone and loop around rectum and going back towards the pubic bone
where is the coccyges to and from
Goes from ischial spine to coccyx
what are the two other muscles within side the pelvis
Obstruator internus and prifomris
- they are both lateral rotators of the hip
what does the piriformis attach to and from
sacrum then attaches to posterior aspect of the femur via greater sciatic formane
what does the obturator internus attach to and from
comes over the obtrusator – passes through the lesser sciatic formane to enter the gluteal region to attach the posterior aspect of the femur
where are the pelvic organs and where are there inferior portions
Pelvic organs are above the pelvic floor and supported by it but the inferior portions such as the urethra vagina and anus pass through the pelvic floor into the perineum
