Exam V: Pelvic Viscera Flashcards
Ureters
Upper half in abdomen, lower half in pelvis
Abdominal part is retroperitoneal
Males: crossed by the ductus deferens; passes between ureter and peritoneum
Females: crossed by the uterine artery, “water under bridge”; forms posterior part of ovarian fossa
Ureters pierce posterolateral edge of bladder; run obliquely through muscular wall of bladder
Ureters: Blood Supply, Innervation, and Lymphatics
Blood supply: arteries arise from renal, gonadal, common and internal iliac, vesical and uterine
(There is a great deal of variation in the blood supply to the ureters and the vessels commonly anastomose.)
Innervation: ureteric nerves from renal, aortic, superior and inferior hypogastric plexus (T10 – L1), both sympathetic and parasympathetic
Lymphatics: from upper part may join renal vessels; lateral aortic nodes/lumbar nodes; common, internal or external iliac nodes
Retropubic Space
behind pubis/anterior to bladder
Bladder
Medial umbilical ligament attaching the bladder to the posterior portion of the anterior abdominal wall
Apex is under the medial umbilical ligament
Neck is what goes down into the urethra
Inside of the bladder: made of detrusor muscle and mucosa
Trigone is always smooth because two structures coming together
Stabilization of the Bladder
Bladder neck held in place by ligaments, thickenings of endopelvic fascia
pubovesical (female)
puboprostatic (male)
Posteriorly held by rectovesical ligaments
The median umbilical ligament attaches bladder to umbilicus
There are also folds of peritoneum that serve to steady the bladder (false ligaments)
Detrusor expands as bladder fills and contracts by parasympathetic stimulation (pelvic splanchnics)
Bladder: Blood Supply, Venous Drainage, Innervation, and Lymphatics
Blood supply: superior vesical aa. inferior vesical aa. (male) vaginal aa. (female) minor aa. from obturator/inf. gluteal
Venous drainage: accompanying veins, vesical venous plexus, prostatic venous plexus
Innervation: pelvic splanchnic nn. (parasympathetic) motor to detrusor m. (more on this later!)
Lymphatics: drain to external and internal iliac nodes
Male Urethra
Divided into 4 parts:
- Preprostatic: extends from base of the bladder and surrounded by internal urtheral spincter
- Prostatic: in prostate, widest and most dilatable part, closer to anterior aspect of prostate; receives openings of ejaculatory and prostatic ducts
- Membranous: located in deep in deep perineal pouch, surrounded by external urethral sphincter
- Spongy: in corpus spongiosum, receives openings of bulbourethral glands, numerous pit like recesses; widens to form navicular fossa
Male Urethra: Blood Supply
inferior vesical, middle rectal, internal pudendal arteries
Female Urethra
female urethra: much shorter than male (4 cm)
More prone to cystitis
Runs from bladder through deep perineal pouch, perineal membrane and opens up into the vestibule anterior to vaginal opening
Receives openings of urethral glands
Paraurethral ducts open at margin of external urethral
Testes
Develop in posterior abdominal wall
Lymphatic drainage is lumbar lymph nodes
External spermatic fascia from the external oblique
Cremastic fascia from internal oblique
Ductus/Vas Deferens
Directly continuous with epididymis
Duct characteristically has small lumen and thick walls
In scrotum, duct is tortuous, then straight
Duct traverses inguinal canal; at deep ring it separates from structures of spermatic cord and enters true pelvis
In the pelvis, ductus covered with peritoneum
Posterior to bladder, ductus deferens: Crosses over ureter between bladder & rectum Becomes enlarged (ampulla) Joins seminal vesicle duct to form ejaculatory duct that connects with the prostatic urethra
Seminal Vesicles
Single coiled tube
Proximal end becomes constricted, straight duct that joins ductus deferens to form ejaculatory duct
Provides bulk of volume to semen (thick alkaline fluid)
Seminal Vesicle Blood Supply
Inferior vesical and middle rectal arteries
Accompanying veins of same name
Ejaculatory Ducts
Union of seminal vesicle ducts & ductus deferens
Terminal opening on seminal colliculus
Bulbourethral Glands
Two small, round glands, in deep perineal pouch, but drain into the spongy urethra
Ducts ~3 cm long, penetrate perineal membrane; pass obliquely forward to open into spongy urethra
The significance of its secretions to seminal fluid is uncertain
Prostate
Glandular and fibromuscular
Secretions make up 20% semen
Posterior wall of prostatic urethra has some notable features.
urethral crest – crest extends down from trigone
seminal colliculus – large bump in middle
prostatic utricle – embryological remnant of vagina
openings of ejaculatory ducts – just below utricle, one on each side
prostatic sinus – on either side of colliculus; openings of prostatic ducts
Prostate: Blood Supply, Venous Drainage, Innervation, and Lymphatics
Blood supply: inferior vesical, internal pudendal and middle rectal arteries
Venous: prostatic venous plexus, communicates with vesicular plexus and internal vertebral plexus
Innervation: pelvic splanchnic nerves (parasympathetic) and inferior hypogastric plexus (sympathetic)
Lymph: internal iliac and sacral nodes
Innervation of the Penis: Prostatectomy
During prostatectomy, care is taken to preserve the prostatic nerve plexus because it is intimately linked to impotence
If resection of plexus is necessary, sural n. grafts have been performed with success
Ovaries
Almond shaped gland in true pelvis
Develop similar to male testes
Ovulate into peritoneal cavity
Held in place by a number of structures:
ovarian ligament
suspensory ligament
mesovarium
Ovaries: Blood Supply, Innervation, and Lymphatics
Blood Supply/Drainage: ovarian arteries and ovarian veins – right to vena cava, left to renal v.
Nerves: pelvic splanchnics - parasympathetic
Lymph: drains to lumbar nodes
4 Parts of the Uterus
Fundus- top, rounded part that lies above opening of uterine tubes
Body- between layers of peritoneum
Isthmus- between body and cervix
Cervix- Surrounds internal opening
3 Layers of the Uterine Wall
Perimetrium: peritoneum and a thin layer of areolar tissue
Myometrium: forms most of the wall; smooth muscle
Endometrium: inner muscous coat, epithelium
Uterus: Cervix, External os, Internal os, Fornix, and Positioning
Cervix- part that surrounds intenal os
External os opens into vagina
Fornix- recess around protruding cervix
Positioning: anteverted and anteflexed; sits on bladder
Uterus Support
The uterus is held in place by ligaments that are thickenings of endopelvic fascia. (transverse cervical and uterosacral ligaments)
Structures most important in uterine support:
- Levator ani
- Urogenital diaphragm
- Other pelvic organs (esp. bladder)
- Uterine ligaments
Transverse cervical (cardinal) ligaments: cervix & lateral fornices of vagina to lateral pelvic wall
Uterosacral ligaments: sides of cervix to middle of sacrum; palpable on rectal exam
Suspensory ligament of the ovary: ovarian vessels covered with peritoneum
Uterus: Broad Ligament and Homologues of the Gubernaculum
Broad ligament – double layer of peritoneum draped over uterus and adnexa in pelvis
Mesosalpinx = portion suspending uterine tube
Mesovarium = portion suspending ovary
Mesometrium = main portion below ovary and uterine tube
Homologues of gubernaculum:
Round ligament – uterus to labia majora
Ovarian ligament – ovary to uterus
Uterus: Blood Supply and Drainage
Blood supply: majority from uterine artery; small contribution from ovarian and vaginal arteries
numerous anastomoses between branches of the uterine artery
Venous drainage: to uterine plexus then to internal iliac veins
Uterus: Innervation and Lymphatics
Lymphatics:
Fundus - drains to lumbar, external iliac
Body – external iliac
Cervix – internal iliac and sacral
The region where uterine tubes join uterus has lymphatic drainage that follows round ligament and drains to superficial inguinal nodes
Innervation: uterovaginal plexus (parasympathetics from S2,3,4 and sympathetics from T12, L1, L2-lumbar splanchnics, intermesenteric, hypogastric plexuses)
Vagina
fibromuscular tube extending from cervix to vestibule (between labia minora)
vaginal walls are usually in contact with each other
Four muscles serve as vaginal sphincters: Pubovaginalis (part of levator ani) External urethral sphincter Urethrovaginal sphincter Bulbospongiosus
superior end of vagina surrounds cervix and extends superiorly forming an anterior, posterior, and lateral fornix
Relations – posterior fornix is deepest & closely related to rectouterine pouch
Pouch of Douglas
Fluid can accumulate with Pouch of Douglas
Patient lays supine and go through vagina and posterior fornix to get to pouch to remove fluid
Inferiorly we get somatic innervation from pudendal
Superiorly we have visceral so don’t feel pain so no anesthesia for this procedure
Vagina: Blood Supply, Venous Drainage, Lymphatics, and Innervation
Blood: uterine & vaginal arteries (br. of middle rectal & internal pudendal aa.)
Venous Drainage: to internal iliac vein
Lymphatics: the lymphatic drainage can be broken down into thirds; the limits of which are poorly defined
upper 2/3 drains to int. and ext. iliac
lower 1/3 drains to superficial inguinal
Nerves:
upper 2/3 gets visceral innervation uterorovaginal plexus (extension from inf. Hypogastric plexus) carries parasympathetic/sympathetic & afferent fibers
lower 1/3 gets somatic innervation from deep perineal br. of Pudendal n.: carries sympathetic and somatic afferent fibers but NO parasympathetics this is the only part of the vagina sensitive to touch and temperature
Uterine Tubes
Hollow tubes that open into peritoneal cavity, empty into uterus, convey oocyte toward uterus and sperm toward oocyte
Has four parts:
- infundibulum – trumpet shaped part with fimbriae
- ampulla
- isthmus
- uterine portion
uterine tube is a three-layered structure (serosa, muscle and epithelium).
broad ligament hangs over uterine tube; mesosalpinx
Uterine Tubes: Blood Supply, Drainage, and Lymphatics
Blood supply/drainage:
ovarian and uterine arteries, (contribution of each is variable)
ovarian and uterine veins
Lymph:lumbar nodes
Peritonitis and Ectopic Pregnancy
Peritonitis occurs much more often in the female – due in large part to the continuity of vagina/uterus with abdominal cavity.
Ectopic pregnancy – outside of uterine cavity
Tubal, abdominal, ovarian, cervical
Not a viable pregnancy because not enough space or blood supply to allow the embryo to grow
“Stone Baby”/ Lithopedion: oocyte implanted in abdominal wall and body closed it off creating a stone baby
Sometimes won’t know the baby is there until severe abdominal pain
Rectum
Continuous with sigmoid colon at S2/S3, indicated by lower end of sigmoid mesocolon, and with anal canal by passing through pelvic diaphragm
Anorectal junction is just in front of tip of coccyx; 80 degree turn
Lower part of rectum is dilated (ampulla); has no sacculations, appendices or mesentery (only superior front and sides are covered with peritoneum)
Teniae coli – spread out to form a single layer
Three permanent transverse rectal folds or valves of Houston
Upper part of the rectum serves a fecal reservoir
Rectum: Blood Supply and Innervation
Blood Supply:
Superior rectal a., middle rectal aa. (from inf. Vesical-male; from uterine-female), inferior rectal aa. from internal pudendal aa.
Sup./Mid./Inf. Rectal Vv.; sup. rectal vv. drain to portal system
Innervation:
Hindgut innervation!!
Sympathetic: lumbar splanchnics/sup. hypogastric plexus
Parasympathetic: pelvic splanchnics (inf. hypogastric plexus)
Cystocele and Rectocele
Prolapse of pelvic viscera due to weakness in the levator ani muscles
Occurs mostly in women that have had many children
