L1 - Defining the Pelvic Region Flashcards
THE BONY PELVIS
i) name the three innominate bones of the pelvis
ii) how many fused sacral vertebrae is the sacrum formed of? is this the same for everyone?
iii) how many fused coccygeal vertebrae is the coccyx made from?
iv) give three roles of the pelvis
v) label bones A,B,C and the foramen D
i) ilium, ischium and pubis
ii) 5 sacral vertebrae fuse to make the sacrum
- can be variation between people
iii) 4 coccygeal vert fuse to make the coccyx
iv) protect the genital tracr, GI system
- muscle attachments
- weight transformation from the spine
v) A = ilium, B = ischium, C = pubis, D = obturator foramen
THE ARTICULATED PELVIS
i) name the two primary joints of the pelvis
ii) which joint is a fibrocartilagenous disc that doesnt allow much movement apart from in pregnancy?
iii) which joint is a secondary cartilagenous joint
iv) where is weight transferred to from the axial skeleton during a) standing and b) sitting
i) sacro-illiac and pubic symphysis
ii) pubic symphysis is a fibrocart disc
iii) sacro-illiac is a secondary cart joint
iv) during standing weight is transf to the femur
- during sitting its transf to the ischial tuberosities
label the pelvis
A = posterior superior iliac spine
B = anterior superior iliac spine (ASIS)
C = ischial tuberosity
D = posterior inferior iliac spine
THE PELVIC BRIM
i) which two components of the sacrum is it formed by? which two lines is it also formed by?
ii) what is it the defining point of?
iii) label A, B and C
i) promontory and ala of sacrum + arcuate and pectineal line
ii) defining point of the true and false pelvis
iii) A = promontory and ala of sacrum
B = arcuate line
C = pectineal line
LIGAMENTS OF THE PELVIS
i) name the four ligaments passing from the sacrum to other parts of the pelvis and where they run from/to
ii) label A,B,C,D on the diagram
i) sacro-iliac - sacrum to ilium (ant and post)
sacro-tuberous - sacrum to medial margin of ischial tuberosity
sacro-coccygeal - sacrum to coccyx
sacro-spinous - sacrum to ischial spine
ii) A = sacroilliac
B = sacrotuberous
C = sacrospinous
D = sacrococcygeal
THE PERINEUM
i) what space does it refer to?
ii) it is a diamond shaped surface extending from the mons pubis to where medially and where posteriorly in women?
iii) a transverse line joining which two structures splits the perineum into two triangles? what are the names of these two triangles?
iv) what does the midpoint of the transverse line define?
v) name the contents of each triangle for men and women
vi) which two spaces are created by the arrangement of the fascial layers in the pelvis?
i) space located at the pelvic outlet and under the muscles of the pelvic floor
ii) ext from mons pubis to medial thighs to gluteal folds posteriorly
iii) transverse line joining the two ischial tuberosities splits the two triangles
- urogenital and anal triangle
iv) midpoint of the line = perineal body
v) females = UG triangle = crura, clitoris and perineal mem
anal triangle = muscles of pelvic floor (levator ani)
males = UG triangle = crura of penis and perineal mem
anal triangle = levator ani and anal apeture
vi) superficial and deep perineal spaces
PERINEAL POUCHES
i) which two structures does the sup perineal pouch sit between?
ii) what does it contain in males (3) and females (4) and both (3)
iii) what is the deep perineal pouch deep to?
iv) what does the deep pouch contain in males (2), females (1) and both (4)
v) label muscles A and B
i) sup perineal pouch sits between the perineal fascia and perineal membrane
ii) sup pouch in males = root of penis, ischiocavernosus and bulbospongiosus
sup pouch in females = clitoris, ischiocavernosus, bulb of vestibule and greater vestibular gland (lubricates)
sup pouch in M&F = urethra, sup transverse perineal muscle, pudendal vessels
iii) deep perineal pouch is deep to the perineal membrane
iv) deep pouch males = bulbourethral gland, dorsal neurovasc of penis
deep pouch females = dorsal neurovasc of clitoris
deep pouch M&F = urethra, ext ureth sphincter, ischioanal fat pads, deep tv perineal muscle
v) A = ischiocavernosus
B = bulbospongiosus
TRUE PELVIC CAVITY
i) what are the posterior, anterior, inferior, superior and lateral borders?
ii) name three things it contains
iii) is it labelled A or B on the diagram?
i) post = sacrum & coccyx
ant = pubic symphysis
inf = pelvic floor
sup = pelvic brim
lateral = obturator internus
iii) reproductive organs/tracts, bladder, rectym
iii) B
PELVIC MUSCULATURE
i) name two muscles that line the wall of the pelvis?
ii) where does each origin and insert? what is the action of each?
iii) which muscle and three muscles in the levator ani line the pelvic floor?
iv) which muscle in the levator ani is responsible for faecal continence and relaxes the internal anal sphincter?
v) label A-E
i) piriformis and obturator internus
ii) piriformis from sacrum to greater trochanter of the femus (travels through greater sciatic foramen)
- action is to lat rotate and abduct
obturator internus - orig at obturator foramen, travels through lesser sciatic foramen and att to greater troch of femus
- action is to lat rotate and abduct
iv) pelvic floor = coccygeus (ischium to coccyx) and levator ani (iliococcygeous, pubococcygeous and puborectalis)
iv) puborectalis controls faecal continence
v) A = piriformis, B = obturator int, C = pubococcygeous, D = puborectalis, E = iliococcygeous
BLOOD SUPPLY AND DRAINAGE TO THE PELVIS
i) which major vessel to all arteries branch from?
ii) name the arteries that come off the anterior portion (8) and the posterior portion (3)
iii) which artery branches from the abdominal aorta and supplies the gonads?
iv) which vein drains into the common iliac veins? which vein drains into the IVC or L renal vein?
v) which artery leaves through the greater sciatic foramen and comes back in through the lesser (under the pelvic floor muscles) why?
vi) label the branches of the posterior internal iliac
i) internal iliac artery
ii) ant internal iliac = superior vesicle, inf vesicle, uterine, vaginal, middle rectal, obturator, int pudendal, inf gluteal
post internal iliac = iliolumbar, lateral sacral, superior gluteal
iii) gonadal artery
iv) int iliac vein drains to common iliac
gonadal vein drains to IVC/renal vein
v) int pudendal leaves through greater and in through lesser sci foramen
- dont want interrupted supply when pelvic floor contract eg cough or sneeze
vi) A = iliolumbar (back on itself)
B = lateral sacral (goes lat)
C = superior gluteal (goes back)
PELVIC NERVES
i) what is the somatic plexus subdivded into? which lumbar level does it start and where does it run to?
ii) which nerve is the major somatic nerve of the sacral plexus?
iii) which nerves provide parasympathetic innervation to the pelvis? what sacral levels do these run through? name a function of psym innervation
iv) name two routes of sympathetic flow to the pelvis? name one function of this
i) somatic plexus = lubosacral (L4-S4) and coccygeal (S4-Co)
- starts L4 and runs to the coccyx
ii) pudendal nerve is the major somatic nerve in the sacral plexus
iii) psym innervation by pelvic splanchnic nerves (S2-S4)
- psym = increased blood flow to erectile tissues
iv) sympathetic flow to pelvis from sacral symp trunk and sup/inf hypogastric plexuses
- symp = orgasm & male ejaculation
PUDENDAL NERVE
i) which foramen does it initially leave the pelvis through?
ii) which canal does it enter when it comes back in?
iii) which four branches does it give rise to?
iv) what does the dorsal nerve supply?
i) leaves through the greater sciatic foramen
ii) pudendal canal
iii) inferior rectal, perineal, post scrotal/labial and dorsal nerve
iv) the penis and clitoris
