Pelvis And Perineum Flashcards
What does the pudendal canal contain?
Internal pudendal vessels
Pudendal nerve
Nerve to obturator internus
What does the superficial fatty layer of subcutaneous fascia contribute to in both triangles?
Urogential: only in females
- labia Majora and mons pubis
Anal triangle: both sexes
- continuous with anal fat pad
What does the superficial membranous collies layer of subcutaneous fascia contribute to in both triangles?
ONLY urogential triangle in both sexes:
- females: continuation of scarpa’s fascia
- males: continuation of scarpa’s fascia and also dartos muscle and fascia
- attaches to fascia lata laterally to end and not go into anal triangle
What does the deep membranous investing layer of perineal fascia contribute to.
Invests all perineal muscles
- continuous with suspensory ligament of penis/clit
- also continuous in the bucks fascia or the penis
Superficial perineal pouch broad definition
Between collies fascia and perineal membrane
Potential space for pooling
Deep perineal pouch broad definition
Space between perineal membrane and inferior pelvic diaphragm fascia
Potential space for pooling
What two superficial perineal muscles maintain erection of the penis/clit?
Bulbospongiosus and ischiocavernosus
Superficial transverse perineal muscle
Stabilizes the perineal body
- perineal body is the site of all perineal muscle attachements
Contents of the superfical perineal pouch for women
Clit
Ischiocavernosus and bulbospongiousus muscles
Superficial transverse perineal muscle
Compressor urethrae muscle
Greater vestibular glands (bartholin glands)
Deep branches of internal pudendal vessels and perineal branches of pudendal nerves
Superficial perineal pouch contents in males
Penis
Ischiocavernosus and bulbospongiosus muscles
Bulb of penis and spongy urethra
Penile Crura and superfical transverse perineal muscle
Deep branches of internal pudendal vessels and perineal branches of pudendal nerves
Deep perineal pouch contents in females
Proximal urethra
External urethral sphincter
Anterior ischio-anal fat pads
Clit neurovasculature
Smooth muscle mass
Deep perineal pouch contents in males
Membraneous urethra
External urethral sphincter
Anterior ischio-anal fat pad
Penile neurovasculature
Deep transverse perineal muscle
Bulbo-urethral glands (Cowper glands)
Scrotal raphe
Splits right and left testicle
- directly continuous with penile raphe
Layers of scrotum from superficial to deep
Scrotal skin
Dartos muscle and fascia
Cremaster muscle
Tunica vaginalis
Tunica albuginea
Site of sperm storage
Tail of epididymus
Epididymis and testis appendix embryological origin/ remnant
Epididymis = wolffian/mesonephric duct
Testis = Mullerian/ paramesonephric duct
Pampiniform venous plexus
Drains rete testis and epididymis to the right and left testicular veins
Found on the spermatic cord
- controls thermoregulatory plexus of testis w/ spermatic cord
Lymphatic drainage of testies and scrotum
Testes drain to lumbar lymph nodes
Scrotum drains to superficial inguinal lymph nodes
Difference between vein drainage between left and right sides
The same except for the left renal vein is larger and does have a direct tributary/branches (left gonadal and left suprarenal vein).
Pudendal nerve branches
Inferior rectal nerve (branches in the lesser static foramen
Perineal nerve (branches medial to ischial tuberosity region)
Dorsal nerve of the penis/clit (inferior to pubic symphysis)
External vs internal anal sphincter
External = skeletal muscle with voluntary innervation (S4)
-Inferior 1/3 of anal canal
Internal = smooth with autonomic innervation
-superior 2/3 anal canal
Pectinate line
Line that demarcates the superior and inferior anal canal
Differences between superior and inferior anal canal
Superior:
- endoderm derived
- supplied by IMA branch
- portal venous system
- autonomic
Inferior:
- ectoderm derived
- supplied by internal iliac
- caval venous System
- somatic via pudendal
Kidney blood supply
Renal -> segment -> inter-lobar artery -> arcuate artery
What portion of the urinalysis bladder is encased in perineum?
Superior portion
Functions of pelvic cavity
Bears weight of upper body
Transfers weight to lower limbs
Provides attachment for musculature
Contains and protects pelvic viscera
Provides support for abdominopelvic viscera
Provides attachment for erectile bodies
Muscles or pelvic diaphragm
Puborectalis: U-shaped sling that is posterior to anorectal canal from contralateral pubic bones
- bends anal canal anteriorly to prevent defecation (also blocks vaginal opening in females)
Pubcoccygeus: medial fibers merge w/ contralateral anococcygeal ligaments
Iiococcygeus
Coccygeus: inferior sacrum to ischial spine
- flexes coccyx and supports pelvic viscera
Levator ani muscles include what?
Puborectalis
Pubococcygeus
Iiococcygeus
Broad ligament
Peritoneal fold between the uterus and lateral body wall of females
Membranous Visceral vs parietal pelvic fascia
Parietal: lines the deep pelvic aspect of muscles forming the walls and floor (parts are named for the muscle they cover)
Visceral: directly ensheaths pelvic organs
- also known as adventitia layer
Hypogastric sheath
Thick band of condensed pelvic fascia that separates retropelvic from retrorectal spaces
Has three laminae
Lamina of hypogastric sheath
Anterior: lateral ligament of the bladder:
- contains superior vesicle arteries and veins
Posterior: lateral rectal ligament
- contains middle rectal artery and vein and rectal nerve plexus
Intermediate lamina: cardinal ligament (females): between uterine cervix and vagina
Rectovesical septum (males): between posterior bladder and prostate
3 sites of constriction in ureters
Ureter and renal pelvis
Ureter and pelvic inlet
Ureter and urinary bladder
What is the broad ligament analogous to in the male
Ureteric fold
Potential spaces in endopelvic fascia
Retropubic and retrorectal
Branches of the internal pudendal artery
Dorsal penile artery
-supplies fibrous tissue, skin and spongy urethra of the penis
Deep penile artery
- supplies heliocentric arteries within corpus cavernosium
What causes an erection?
Parasympathetic fibers stimulate helicine arteries to relax allowing blood to fill
- prevents venous drainage by bucks fascia being pushed up against them compressing the deep penile vein
Broad ligament and its peritoneum layers
Suspends the uterus and ovaries
Mesovarium (perineum over the ovaries)
Mesometrium (perineum over the uterus)
Mesosalpix (perineum over the uterine tubes)
Uterine isthmus (internal os)
Separates uterus from the cervix
Also separate line for perineum
Active and passive support of the uterus
Active = pelvic diaphragm and cardinal ligaments
Passive = urinary bladder
Parts of uterine tube (from distal to proximal uterus)
Infundiblum w/ fimbriae
Ampulla
Isthmus
Uterine part
Ovary is attached at the isthmus and ampulla but the eggs enter the infundibulum first
Suspensory ligaments of the ovaries
Suspend the ovaries intraperitioneal and house the ovarian vessels, lymphatic and nerves
Ovarian ligaments are remnants of the female gubernaculum
Innervation of the vagina
Inferior 1/4th
- somatic innervation (perineal nerve)
- sensitivity to pain, temp and touch
Superior 3/4
- visceral innervation
- inferior hypogastric plexus -> uterovaginal plexus nerves
Autonomic innervation of micturition
Parasympathetic:
- relaxes internal urethral sphincter and anal sphincters
- contracts destructor muscle
Sympathetic:
- vasoconstriction of renal vessels
- contraction of internal urethral sphincter
