Pelvis Lecture 2

internal iliac artery

primary arterial source for pelvic walls, viscera, gluteal region, and perineum

female arterial supply pattern

internal iliac, ovarian, median sacral, and superior rectal contributions

male arterial supply pattern

internal iliac, median sacral, and superior rectal contributions

branch logic

anterior division is mainly visceral/perineal and posterior division is mainly parietal/pluteal

corona mortis

variant accessory obturator artery anastomosed with obturator artery or vein

anterior division of arterial supply

umbilical/superior vesical, obturator, inferior vesical or vaginal, uterine, middle rectal

perineal routes of arterial supply

internal pudendal supplies perineum and erectile tissues

gluteal route of arterial supply

inferior gluteal exits below piriformis

posterior division of arterial supply

iliolumbar, lateral sacral, superior gluteal

"water under the bridge"

uterine artery crosses superior to the ureter

visceral venous plexuses

rectal, vesical, prostatic, uterine, and vaginal plexuses interconnect

primary venous drainage

internal iliac veins, common iliac veins, IVC

portosystemic venous link

superior rectal vein connects portal system to systemic rectal veins

vertebral venous link

batson plexus provides valveless pathway to vertebral column

what may spread to the spine through valveless vertebral venous plexuses?

pelvic malignancies

external iliac lymph nodes

anterosuperior pelvic viscera and superficial inguinal inflow

internal iliac lymph nodes

deep pelvic viscera, pelvic floor, and deep perineum

sacral lymph nodes

posteroinferior pelvic viscera

common iliac lymph nodes

convergence before lumbar/para-aortic drainage

what does lymph node prediction depend on?

organ level

course of ureters

cross pelvic brim anterior to iliac bifurcation

lateral wall of ureters pass where?

medial to obturator neurovascular structures

key crossing of ureters

uterine artery or ductus deferens passes superior to ureter

bladder entry of ureters

oblique posterolateral tunnel forms anti-reflux valve

where is a common stone impaction?

ureter pelvic junction, pelvic brim, ureter vesicular junction

ureteropelvic junction (UPJ)

where the kidney meets the ureter

mid-ureter

where the ureter crosses the iliac vessels

vesicoureteric junction (VUJ)

where the ureter enters the bladder

why is the bladder considered a reservoir?

distensible muscular organ that rises into abdomen when full

detrusor muscle of bladder

interlacing smooth muscle that is prominent in the internal sphincter in males

trigone muscle of bladder

smooth posteroinferior triangle between ureteric and urethral orifices

what is the sympathetic control of the bladder?

stores urine

what is the parasympathetic control of the bladder?

voids urine

when is the bladder considered an abdominal organ?

before puberty

primary arterial supply of bladder

branches of internal iliac arteries

what parts of the bladder are supplied by superior vesical arteries?

anterosuperior parts

what parts of the bladder are supplied by inferior vesical arteries in males?

fundus and neck

what parts of the bladder are supplied by vaginal arteries in females?

fundus and neck

cystocele

loss of bladder support in females that causes damage to perineal muscles or associated fascia

suprapubic cystotomy

bladder when empty lies at level of superior margin of pubic symphysis

cystoscopy

visualization of internal bladder

what can be done in a cystoscopy?

remove stones and tumors

male urethra segments

intramural, prostatic, intermediate, spongy

what is unique about the male urethra intermediate segment?

narrow and fixed, making it vulnerable in pelvic fracture

female urethra

short course from bladder neck to vestibule

why do females have a higher uti risk?

shorter urethra

paraurethral glands

homologues to prostate

what provides continence?

external urethral sphincter and pelvic floor provide voluntary control

arterial supply of proximal urethra in males

prostatic branches of inferior vesical and middle rectal artery

ductus deferens

crosses ureter and expands as ampulla before ejaculatory duct

seminal glands

produce alkaline fructose-rich fluid and are the major seminal volume contributors

prostate zones

peripheral zone and transition zone

peripheral zone of prostate

common site for cancer

transition zone of prostate

benign prostatic hyperplasia

what does the prostate respond to?

estrogen

bulbourethral glands

deep perineal pouch with ducts that open into proximal spongy urethra

what evaluates the posterior peripheral zone of the prostate?

digital rectal exam

vaginal canal

musculomembranous tube from cervix to vestibule

how long is the vagina?

7-9 cm

relation of vagina to other organs

posterior to urethra and bladder and anterior to rectum

fornices of vagina

posterior fornix lies near rectouterine pouch

hymen

thin, elastic muscousal membrane, often ring around vaginal orifice

compression of vagina

pubovaginalis muscle, external urethral sphincter, urethrovaginal sphincter, bulbospongiosus muscle

what accesses rectouterine pouch through the posterior fornix?

culdocentesis

superior arterial supply of vagina

uterine arteries

meddle and inferior arterial supply of vagina

vaginal and internal pudendal arteries

superior lymphatic drainage of vagina

internal and external iliac lymph nodes

middle lymphatic drainage of vagina

internal iliac lymph nodes

inferior lymphatic drainage of vagina

sacral and common iliac lymph nodes

open communication between vagina and other viscera

fistula

normal position of uterus

anteverted relative to vagina and anteflexed at cervix/body junction

parts of uterus

fundus, body, isthmus, cervix

wall layers of uterus

perimetrium, myometrium, endometrium

cervix

transformation zone at external os is sampled during pap smear

what can predispose to uterine prolapse?

retroverseion and pelvic floor weakness

infant uterine proportions (body:cervix)

2:1 do to maternal hormones

child uterine proportions (body:cervix)

1:1

adult fertile nulliparous uterine proportions (body:cervix)

2:1

adult multiparous uterine proportions (body:cervix)

3:1

elderly posmenopausal uterine proportions (body:cervix)

1:1

broad ligament of uterus

mesosalpinz, mesovarium, and mesometrium

cardinal ligament of uterus

major lateral cervical support and contains uterine vessels

uterosacral ligament

anchors cervix to sacrum

round ligament of uterus

uterine born to labia major via inguinal canal

when does ligation of uterine artery near ureter cause risk?

hysterectomy

somatic innervation of vagina and uterus

deep perineal nerve which is a branch of pudendal nerve

visceral innervation of vagina and uterus

uterovaginal nerve plexus in base of broad ligament that has sympathetic, parasympathetic and visceral afferent fibers

general anesthesia for childbirth

no awareness of labor and delivery but also not aware of earliest moments of infant's life

spinal block for childbirth

anesthetic introduced into spinal subarachnoid space at L3-L4 and produces complete anesthesia inferior to the waist

pudendal nerve block for childbirth

peripheral block that gives local anesthesia over S2-S4 dermatome (perineum) and inferior quarter of vagina, does not block pain from superior birth canal, headache possible

caudal epidural block for childbirth

must be delivered in advance of actual delivery, bathes the S2-S4 spinal nerve roots including pain fibers from uterine cervix and superior vagina so entire birth canal, pelvic floor, and majority of perineum are anesthetized, lower limbs are not usually affected, pain fibers from uterine body not affected, no spinal headaches as vertebral epidural space is not continuous with cranial epidural space

uterine tub segments

infundibulum, ampulla, isthmus, intramural part

ampulla of uterine tube

most common site of fertilization and ectopic pregnancy

ovary support

mesovarium, suspensory ligament, ligament of ovary

vessels of ovaries and uterine tubes

ovarian arteries arise from abdominal aorta; right vein to IVC; left vein to left renal vein

what ligament contains ovarian vessels and is important during oophorectomy

suspensory ligament

extend of rectum

S3 rectosigmoid junction to anorectal junction

sacral flexure

follows sacrum and coccyx

anorectal angle

about 80 degrees and is maintained by puborectalis muscle

what muscle provides fecal continence?

puborectalis