B8-005 Pelvis and Perineum Flashcards
best way to differentiate male vs female bony pelvis
angle of pelvic arch
male: narrow (peace sign)
female: wider (thumb and index)
ligament of the SI joint that helps in transferring weight and keeps the sacrum and ilium snug together
interosseous sacro-iliac ligament
fibrocartilage disc joining the pelvic ring
pubic symphysis
anterior inferior wall of the pelvic cavity [2]
pubic bones
pubic symphysis
lateral wall of the pelvic cavity [2]
obturator foramen
obturator internus and fascia
posterior wall of the pelvic cavity [3]
sacrum
piriformis
sacral plexus (S1-2)
muscles making up the pelvic floor (diaphragm) [2]
coccygeus
levator ani
3 muscles that make up levator ani
puborectalis
pubococcygeus
iliococcygeus
major support for pelvic viscera
pelvic floor- always contracted
(weakness causes organ prolapse)
muscle of pelvic floor that helps maintain fecal continence
puborectalis
(sling between rectum and anus)
the […] of levator ani provides major support for abdominal organs
tendinous arch
the […] muscle of the bladder is under autonomic control
detrusor
in males, the […] is directly inferior to the bladder
prostate
if the bladder ruptures superiorly, where will the fluid go?
into abdominal cavity —> rectovesical pouch
(or recto-uterine pouch in females)
if the bladder ruptures inferiorly, where will the fluid go?
into the perineum
the [male/female] external urethral sphincter is more like a tube/trough that extends vertical to the trunk of the bladder
male
the [male/female] external urethral sphincter has 3 sections
female
external urethral sphincter
compressor urethrae
urethrovaginal sphincter
what spinal level is the rectosigmoid junction located at?
S3
where are feces stored?
rectal ampulla
above the pectinate line, the rectum was formed from what germinal layer?
endoderm
below the pectinate line, the rectum was formed from what germinal layer?
ectoderm
where does blood supply to the rectum stem from above the pectinate line?
IMA via superior rectal a.
where does blood supply to the rectum stem from below the pectinate line?
internal pudendal via inferior rectal a.
where do the lymphatics drain to from the rectum above the pectinate line?
internal iliac nodes
where do the lymphatics drain to from the rectum below the pectinate line?
superficial inguinal nodes
nerve supply above the pectinate line of the rectum is [autonomic/somatic]
autonomic
nerve supply below the pectinate line of the rectum is [somatic/autonomic]
somatic (pudendal n.)
internal anal sphincter is under […] control
autonomic
external anal sphincter is under […] control
voluntary (via inferior rectal n.)
what structure is located between the fascia of the obturator internus and muscle?
pudendal canal (contains pudendal nerve, inferior rectal arteries and veins)
main muscles of the pelvic floor torn during labor and delivery [2]
pubococcygeus
puborectalis
bladder protruding into anterior wall of the vagina
cystocele
what structures of the pelvic floor lead to a cystocele when damaged? [4]
levator ani
tendinous arch
uterosacral ligament
cardinal ligament
(in order of most likely to be damaged)
rectum herniates into posterior vaginal wall
rectocele
what structures of the pelvic floor lead to a rectocele when damaged? [3]
perineal body (central tendon)
perineal membrane
transverse perineal muscles
intestinal contents pushing into vaginal wall
enterocele
what structures of the pelvic floor lead to a enterocele when damaged? [1]
levator ani
structures contained in the anal triangle of the perineum [3]
ischioanal fossa
pudendal canal
anal canal
structures contained in the urogenital triangle of the perineum [3]
urethra
vagina (female)
spaces
important structures contained in the ischioanal fossa
pudendal canal –> inferior rectal arteries
large amount of adipose (allows for large abscess formation)
superficial pouch lies between what two structures?
perineal membrane
superficial perineal fascia (Colles fascia)
fascia that is continuous with the fascia of the penis, darto’s, and scarpa’s fascia
Colles
deep pouch lies between what three structures?
levator ani
obturator internus
perineal membrane
the dorsal nerve/arteries of the clitoris/penis lie in which pouch?
deep
the bulbo-urethral glands lie in which pouch?
deep
the urethra lies in which pouch?
deep
the external urethral sphincter lies in which pouch?
deep
the anterior recess of the ischionanal fossa lies in which pouch?
deep
the bulb of the penis/vestibule is covered with […] muscle
bulbospongiosus
the crus of the penis/clitoris is covered with […] muscle
ischiocavernosus
the perineal branches of internal pudendal travel through the […] pouch
superficial
the transverse perineal muscles travel through the […] pouch
superficial
the crus of the penis/clitoris travel through the […] pouch
superficial
the bulb of the penis/vestibule travel through the […] pouch
superficial
parts of the male urethra [4]
intramural
prostatic
intermediate (membranous)
spongy (penile)
the two crura become the […] in the body of the penis
corpus cavernosa
what artery runs in the corpus cavernosa of the penis?
deep artery
corpus cavernosa is surrounded by
tunica albuginea
the corpus spongiosum contains the […] urethra
spongy
all three erectile bodies are covered by […] fascia
Buck’s
(deep fascia; continuous with colles)
what vessels/nerves are located on the dorsal side of the penis?
superficial dorsal vein
Buck’s fascia
deep dorsal vein, dorsal artery, nerve
fracture of the superior pelvic rami endangers what structure in men?
ductus deferens
crosses the posterior pelvic brim at the ala of the sacrum
sympathetic chain
contains the inferior rectal nerves
ischiorectal fossa
part of the urethra located at the neck of the bladder and superior to the prostate
intramural
part of the urethra that passes through the deep perineal pouch
membranous
[male or female pelvis]
oval shaped inlet
female
[male or female pelvis]
larger pubic angle
female
[male or female pelvis]
shorter, wider sacrum
female
[male or female pelvis]
wider, shallower cavity
female
[male or female pelvis]
lesser pubic angle
male
[male or female pelvis]
narrower, deeper cavity
male
[male or female pelvis]
narrower, longer sacrum
male
[male or female pelvis]
smaller pelvic outlet
male
tearing of the pelvic floor during childbirth leads to partial paralysis of what muscle?
levator ani
a third degree vaginal tear could damage what structure of the rectum?
external anal sphincter
layers of spermatic cord and fascia derivatives
External spermatic fascia
(external oblique)
Cremasteric muscle/fascia
(internal oblique)
Internal spermatic fascia
(trasversalis fascia)
ICE tie
inguinal canal contents
round ligament (female)
vas deferens (male)
ilioinguinal nerve
internal spermatic vessel
hernia medial to inferior epigastric vessels
direct
MDs don’t LIe
hernia lateral to inferior epigastric vessels
indirect
MDs dont LIe
visceral innervation above the pectinate line comes from
lumbar splanchnics via inferior hypogastric plexus
lymphatics above the pectinate line drain into the
internal iliac lymph nodes
veins above the pectinate line drain into the […] system
portal system
artery supplying rectum above pectinate line
superior rectal a.
somatic innervation below the pectinate line
pudendal nerve
artery supplying rectum below pectinate line
inferior rectal
veins below the pectinate line drain into the […] system
caval system
lymphatics below the pectinate line drain into the
superficial inguinal nodes
where will urine collect following injury to the superior bladder?
intraperitoneal space
(raises BUN and creatinine due to peritoneal absorption)
where will urine collect following injury to the anterior bladder wall or neck?
retropubic space
(associated with pelvic fracture)
where will urine collect following injury to the anterior urethra?
(usually due to straddle injury)
scrotum –> scrotal hematoma
If Buck’s fascia is torn, it will also go into superficial perineal space
where will urine collect following injury to the posterior urethra?
(usually due to pelvic fracture)
retropubic space and deep perineal space
a high riding prostate may indicate injury to what part of the urethra?
posterior
(usually due to pelvic fracture)
located in the lateral wall of the ischioanal fossa
pudendal canal
fat filled space on either side of the anal canal
ischioanal fossa
the root of the penis includes the crura, which is covered by the […] muscle, and the bulb which is covered by the […] muscle and located in the […] pouch
crura - ischiocavernosus muscle
bulb- bulbospongiosus muscle
superficial
