Interval 5 Flashcards
Location of pelvic viscera:
lesser pelvis
-pelvic diaphragm: major muscle is levator ani
Perineum:
- space that contains any structure below the pelvic diaphragm
- where the roots of the male/female external genitalia is found
Components of pelvic bone:
- ilium
- between the ilium and ischium on the lateral (back) side is the tuberosity
- ischium (posterior)
- pubis (anterior)
Fusion of the innominate bones:
- articulate anteriorly at the pubic symphysis *ischium dont touch
- articulate posteriorly with the sacrum at sacroiliac joints *the ilium dont touch
Pelvic brim:
series of bony parts that separate greater and lesser pelvis
Greater pelvis:
part of the abdominal wall
Male versus female pelvis:
FEMALE:
- shallower pelvis
- opening is wider
- oval pelvic inlet
- ischiopubic rami is wider angle (thumb and index)
MALE:
- pelvic inlet is heart shaped
- ischiopubic rami is index and middle finger
Female pubic bone:
- true obstetric conjugate: anterior - posterior line typically slightly greater than 10 cm
- interspinous distance (ischial spine to the other): transverse plane - smallest diameter
Pelvic diaphrams:
- two skeletal muscle diaphragms (like the abdominal skeletal muscle diaphragm)
- pelvic: funnel shaped, external anal sphincter
- urogenital diaphragm: stretched across the width of the perineum, skeletal muscle, shorter, sphincter urethrae
- tonic contraction of these keeps bowl movement in
Pelvic diaphragm:
-3 parts, named after the bone that makes them up
1) Levator ani:
- Pubococcygeus(vagina/prostate and anorectal) and puborectalis (form sling for anterior part of anal canal): pubic bone
- Illiococcygeus
2) ischio coccygeus - funnel SHAPE and attach to ligament by the coccyx
- supports the bladder and the prostate gland
What transverses the pelvic diaphragm?
- female: urethra, vagina, anal canal
- male: urethra, anal canal
Obturator internus:
-blocks ischio coccygeus from having bony attachment so attaches to the tendinous arch of obturator fascia
Pudental neurovascular bundle:
- ventral rami that innervate the skeletal muscle of the two diaphragms and providing voluntary control of the sphincter
- S2, 3, 4
Ischioanal fossa
-tissue and fat that can be distended when fecal components stretch the anal canal
Internal sphincter muscle and innervation:
-smooth muscle, sympathetic innervation
Extrernal sphincter muscle:
- skeletal
- maintains urinary contents
- both sexes
- urogenital diaphragm location
Bladder:
- wall muscle is detrusor smooth muscle, contraction empties urine
- urethra in males transverse the length of the prostate, female it is shorter
- transitional epithelium
Prostate:
-release seminal fluid into the urethra via ejaculatory ducts
Internal urethral sphincter
- prevents reflux of sperm and seminal fluid into the bladder
- males (small in females)
- above the prostate, before the bladder
- smooth muscle, sympathetic control
transparent peritoneum
-covers the pelvic viscera
Rectovesical pouch
- reflection between the posterior bladder and anterior rectum
- most inferior extent of the male peritoneal cavity
- potential space normally filled up by gut structures or the rectum pushing up against the bladder
Seminal vesicle:
-second gland that like the prostate produces seminal fluid
Male continuous duct system:
- epididymous -> ductus deferens -> ejaculatory duct (where the seminal vesicle and ductus merge above the prostate)
ductus: courses in close proximity to the seminal vesicle
ductus deferens:
- water under the bridge (ductus goes obliquely to urether
- runs medial to the seminal vesicle
Prostate cancer:
- peripheral zone: site of adenocarcinoma, contains true prostatic glands POSTERIOR thats why the finger can push against the anterior wall of the rectum which is against the posterior wall of the prostate and can feel whether there is a metastatic condition there
- periurethral zone: sites of BPH (benign prostatic hyperplasia) ANTERIOR
Female peritoneal reflection points:
- two due to the presence of the uterus
- vesicouterine and rectouterine pouch of Douglas more significant and deeper (most inferior portion of the female peritoneal cavity)
Vestibule
-common chamber into which the short urethra terminates and inferior opening of the vagina
Posterior fornix:
-arch shaped space where the rectouterine pouch extends between the uterus and rectum
Angles of flexion from the uterus folding over the bladder:
-uterus is anteverted and antiflexed
Broad ligament:
peritoneal covering of the uterus, uterine tubes, ovaries (it is a mesentery with a front and back)
- mesentery: double layer of peritoneum
- the clear covering that dr. white covered himself (the uterus) with
Secondarily peritoneal:
- uterus, uterine tubes, ovaries
- didnt start out with a peritoneum during development but then developed one later
Parts of the broad ligament:
- mesosalpinx
- mesovarium
- mesometrium
Cardinal ligament:
- each of the ureters passes through the base of the broad ligament
- this is the fascia that supports the uterus
Immediately after ovulation where is the ovum?
- inside the peritoneal cavity after passing through the peritoneum covering the ovary
- each uterine tube punches a hole in the peritoneal wall to allow this to go out
- females more likely to get peritonitus because of these two tiny holes in the peritoneum
Ampulla of the uterine tube:
- inside the peritoneal cavity
- site of fertilization and ectopic implantation
Ovary and peritoneal cavity
-ovary is not in the cavity but extrudes the secondary oocyte into the peritoneal cavity
subpubic symphysis:
where the ischiopubic rami unite
divisions of the pelvic outlet:
- urogenital triangle: directly behind the pubic symphysis
- anal triangle: posterior to the urogenital
- lateral border of both at the ischial tuberosities
perineal body:
central tendon of the perineum
-midline between the ischial tuberosities
Pelvis divisions:
greater (false) - contains iliacus muscle, shallower in females
lesser (true) - formed by the hipbones
pelvic diaphragm innervation:
skeletal muscle innervated directly by ventral rami S2 and S3 spinal nerves and of the pudendal nerve
Ischioanal fossa:
encloses the pelvic diaphragm
fat and CT
Where does the pelvic diaphram insert?
coccyx
Bladder:
- retroperitoneal
- superior aspect covered by peritoneum which reflects on anterior aspect of uterus (vesicouterine pouch) or rectum (rectovesical pouch)
- located below/posterior to the pubic bone
Components of the bladder:
- trigone: inner posterior wall, where ureters open into the bladder - urethra opens at the apex
- detrusor muscle: smooth muscle that contracts to allow passage of urine
- sphincter vesica (internal urethral sphincter): smooth muscle that encircles the urethra at the junction of the bladder
- sphincter urethrae (external): smooth muscle that encircles the urethra at the urogenital diaphragm
Male urethra parts:
- prostatic: bladder-prostate - urogenital hiatus of the pelvic diaphragm (internal sphincter)
- membranous: external sphincter in the urogenital diapgram
- penile: transverses the bulb and corpus spongiosum
- 12 cm
Female urethra:
*5 cm
opens into the vestibule just anterior to the opening of the vagina
*more elastic, easier to put in a catheter
anococcygeal ligament:
joins the anal canal to the coccyx
Parts of the anal canal:
- contains anal columns which contain the superior rectal artery and veins
- divided into parts by the pectinate line
1) Above: lined by muscosa, superior rectal artery and internal rectal venous plexus (drains to superior rectal vein), lymph to the internal iliac nodes, innervated by the ANS (not sensitive to pain) - visceral
2) below: lined by skin, inferior rectal artery and external rectal venous plexus (drains to the internal iliac vein), lymph to the superficial inguinal nodes, sensory innervation by the pudendal nerve
anal canal sphincters:
- internal: smooth muscle innervated by sympathetic (contraction) and parasympathetic (relax)
- external: skeletal muscle from the puborectalis muscle, voluntary control via inferior rectal branches of the pudendal nerve
ductus deferens:
- arises from the epididymis transverse the inguinal canal, goes into the pelvis and reaches the posterior aspect of the bladder
- transports sperm from the speminiferous tubules
seminal vesicles
- on the bladder, just lateral to the ductus deferens
- secrete fructose rich seminal fluid
- sperm metabolism, major component of semen
ejaculatory duct:
- ductus deferns joining with the seminal vesicle (just above the prostate)
- transports sperm and seminal fluid through the prostate
prostate:
- consists of glandular tissue and smooth muscle
- periurethral zone: surrounds the urethra and contains gland (site of BPH)
- peripheral zone: contains the main prostatic glands which secrete prostatic acid phosphatase and prostate specific antigen which contribute to sperm motility and activation (cancer site)
What passes through the funnel of the pelvic diaphragm in males?
- anteriorly: urethra
- posteriorly: anal canal
Uterus:
- between the bladder and the rectum
- smooth muscle
- fundus, body, an isthmus, and cervix
- anteverted in 50% of females (folded anteriorly at the junction of the cervix) could be retroverted (folded posteriorly or in midline position
Uterus facilitates:
- movement of sperm from cervix
- protective environment for embryo
- contracts to push out fetus
uterine tubes:
- intramural part, isthmus, ampulla, and infundibulum (contains the ostium which opens into the peritoneal cavity)
- facilitates the transport of sperm from the uterus and ovum to the uterus
Vagina:
- connects the uterus to the vestibule
- encircles cervix at the fornix
- passes through the urogenital hiatus of the pelvic diaphragm and urogenital diaphragm
Cervix:
- external opening: at the endocervical canal
- internal opening
What is covered by peritoneum in the female?
-upper portions of the bladder, anterior/posterior uterus (uterine tube and ovaries), upper/anterior rectum
urogenital diaphragm:
- skeletal muscle
- contains deep transversus perineus muscle and sphincter urethrae (external)
- perineal membrane covers the inferior surface
- site of attachment of the erectile bodies/skeletal muscle roots of the penis and the clitoris
deep perineal pouch:
- contains deep transversus perineus muscle and sphincter urethrae (external)
- between superior/inferior fascia layers of the UG diaphragm
- males: membranous urethra and bulbourethral (Cowpers) glands
- female: urethra and vagina
superficial perineal pouch:
- crura and bulbs of the penis/clitoris
- attached to the ichiopubic rami and perineal membrane
- continue as corpora cavernose into penis/clitoris
Bulbs:
males: bulb of penis lies in the midline, contains penile urethra
females: bulb of the vestibule in the wall of the vestibule with the greater vestibular (Bartholins) glands
Muscle of the crura and bulbs:
- skeletal
crura: ischiocavernous muscle (attach to bulb or penis or vestibule)
bulb: bulbospongiosus (contract in males during ejaculation/micturition) - both contract during sex to limit venous drainage
Colle’s fascia:
- forms the superficial fascial boundary of superficial perineal space
- continuous with the fascia of the scrotum, penis/clitoris, and Scarpa’s
Muscles IN the penis:
- 2 corpora cavernose
- corpus spongiosum
Paraurethral glands of Littre:
adjacent to the penile urethra
-lubricate the penile urethra
Buck’s fasica (deep penile)
-encloses the 3 erectile bodies, deep dorsal vein, dorsal nerves, and arteries
Labia majora:
- CT and fat
- homologous to the scrotum
- round ligaments of the uterus end here
labia minora:
-in the lateral walls of the vestibule
vestibule:
-chamber into which the urethra and vagina open after passing through the UG diaphragm
paraurethral (Skene’s) glands:
- homologous to the prostate
- lubricate the urethra and the vestibule
Clitoris:
-2 corpa cavernose
Blood supply to the pelvic viscera:
internal iliac artery
Bladder blood supply:
-superior vesical arteries that come from the umbilical artery
Uterus blood supply:
-uterine artery, branch of the umbilical artery courses through the round ligament
ductus deferens and testis blood supply:
- inferior vesical artery
* also supplies the bladder and prostate
bladder and vagina blood supply:
-vaginal artery, branch of uterine
Rectum and anal canal blood supply:
- middle rectal artery
- branch of the internal pudendal artery
Internal pudendal artery:
- supplies structures in perineum
- exits pelvis via greater sciatic foramen and passes through lesser
Inferior rectal artery:
-supplies anal canal below pelvic diaphragm
perineal branchs of internal pudendal:
-muscles in the superficial and deep perineal pouches, skin of labia, vestibule, and scrotum
Deep artery/artery to the bulb
-supply penis/clitoris, erectile tissue, bulbourethral gland, greater vestibular gland
dorsal artery:
-skin of penis/clitoris, erectile tissue
iliolumbar artery:
-supplies iliacus, psoas major/minor, quadratus lumborum
lateral sacral artery:
-structures in the walls of the lesser pelvis
Pudendal nerve:
- innervates skeletal muscle of the pelvic diaphrahm, perineal pouches, and skin that overlies the perineum
- formed by ventral rami of S2, 3, 4
- passes through the greater sciatic foramen crosses ischial spine and enters the pudendal canal through the lesser sciatic foramen
3 branches of the pudendal nerve:
- inferior rectal nerve: innervates the external sphincter, skin of the anal triangle, and skin of the anal canal
- perineal nerve: skin of posterior scrotum and labia majora/vestibule. Deep branch innervates superficial/deep perineal pouch muscles (transverse perineus, sphincter urethrae, bulbospongiosus, ischiocavernosus)
- dorsal nerve of the penis/clitoris: skin
Pudendal sensory nerve:
-general sensory fibers that convey pain from the structures in the perineum
Motor functions of the pudendal nerve:
- contraction of sphincter urethrae (voluntarily prevent urination)
- contaction of external anal sphincter (voluntarily keep feces in)
- supports pelvic viscera/prevents prollapse by contracting skeletal muscles in pelvic/UG diaphragms
- maintains erection
- contract bulbospongiosus for ejaculation and micturition
Sympathetic innervation of the pelvis/perineum:
- lower thoracic and lumbar splanchnics
- preganglionic sympathetic axons from T11-L2 spinal cord
- synapse at inferior mesenteric ganglion or prevertebral ganglia in the inferior hypogastic plexus
Superior hypogastric plexus contains:
- visceral pain fibers ad sympathetic axons
- visceral pain fibers course back to the spinal cord with the thoracic and lumber splanchnics
lower thoracic and lumbar splanchnic functions:
- contraction of sphincter vesicae (bladder filling, prevents retrograde ejaculation)
- contraction of smooth muscle in ductus deferens, prostate, and seminal vesicles pushes sperm to the prosthetic urethra
- emptying of the secretory products of the bulbourethral and greater vestibular glands
- contraction of the internal anal sphincter (maintains feces)
- carry visceral pain sensations from the GI structures in the hindgut and from pelvic viscera
- carry pain from fundus, body, and cervix of the uterus
- pain can be referred to the T11-L1 dermatomes
Parasympathetic innervation of the pelvis and perineum:
- pelvic splanchnic nerves
- contain preganglionic parasympathetic axons that arise from neurons in the S2, 3, 4 spinal cord segments
- they branch from the ventral rami of S2, 3, 4 spinal nerves as they emerge from the ventral sacral foramina
- synapse in terminal ganglia situated in the wall of the bladder and in the hind gut and inferior hypogastric plexus
- contain sensory fibers that respond to bladder distention, rectal distention, and distension of the uterus
Inferior hypogastric plexus
-parasympathetic pelvic splanchnic join with the sympathetic splanchnic nerves in the superior hypogastric plexus to form the inferior hypogastric plexus
Motor functions of the pelvic splanchnic nerves:
- contraction of the detrusor muscle in the bladder wall = micturition
- relax the internal anal sphincter and contraction of smooth muscle in the ampulla of rectum = defecation
- dilation of the helicine arteries = erection
- stimulate the secretory activity of the prostate, seminal vesicles, bulbourethral and greater vestibular glands
Micturition:
- urine flows from the bladder to the urethra
- mediated by vesical relax which has two stages: filling and emptying and is facilitated by parasympathetic, sympathetic, and pudendal nerves
Filling stage:
- pelvic sphlanchnic nerves contain sensory fibers which sense urine
- CNS bladder storage system is activated, sympathetic nerves inhibit the detrusor allowing bladder walls to stretch
- bladder walls obstruct the entry point of the ureters to prevent reflux
- at micturition threshold, conscious appreciation of bladder fullness
- pain fibers course with the thoracic and lumbar splanchnic nerves and refer pain to T11 - L1 dermatomes (lower abdominal wall)
Emptying stage:
- CNS micturition center activated
- sphincter urethrae and sphincter vesicae relax
- pelvic sphlanchnic nerves contract detrusor and urine passes
- bulbospongiosus muscle in males contracts to expel urine from the penile urethra
- thoracoabdominal diaphragm and abdominal muscles contract to increase intrapelvic pressue and speed up flow
Micturition disorders:
- CNS control center lesions: cause supraspinal bladder disorders where bladder fills and empties suddenly
- lesions above the sacral level of spinal cord: spinal, autonomic, spastic bladder where parasympathetic neurons are not inhibited when bladder is stretched so detrusor contracts after minimum stretch and there is frequent urination (small bladder, some urine can stay, risk of infection)
- lesions to the sacral spinal cord or roots of sacral spinal nerves: atonic bladder due to disruption of the vesical reflex, bladder fills but urine dribblers because detrusor fails to contact and urethral sphincter may be weaker (high infection risk)
Defecation:
- visceral sensory fibers course into the sacral spinal cord in pelvic splanchnic nerves
- pelvic splanchnic nerves facilitate peristalsis via stimulation of smooth muscle in the rectum
- internal/external sphincter are inhibited allowing emptying
Sexual reflexes:
- erection -> secretion -> emission -> ejaculation
- erection: pelvic splanchnic and postganglionic cavernous
erection
- pelvic splanchnic and postganglionic cavernous
- relation of smooth muscle
- dilation of arteries in the erectile tissue of the crura and corpora cavernosa, bulb, and corpus spongiosum
- ischiocavernous and bulbospongiosus muscle contractions help maintain erection
- parasympathetic
Point and shoot (erection and emission parasympathetic and sympathetic)
Sectretion:
- also pelvic splanchnic nerves
males: stimulate secretory activity of the prostate and seminal vesicles
female: stimulate secretory activity of the vaginal glands and greater vestibular glands (vagina moves to midposition in pelvis)
Emission:
- facilitated by lower thoracic and lumber splanchnics (sympathetic)
- contraction of smooth muscle in ductus deferens and prostate/seminal vesicles promotes movement of sperm
- contraction of sphincter vesicae prevents retrograde ejaculation
- ejaculation closely follows emission
Ejaculation:
- facilitated by the prudendal nerve
- sphincter urethrae relaxes
- rhythmic contractions of the bulbospongiosus propels sperm
Sacrospinous ligament
converts the greater sciatic notch to the greater sciatic foramen
Ureter courses:
-inferior to the uterine artery
Location of the UG diaphragm:
- runs horizontal
- below the ischiocavernosus muscle
- between the prostate and the bulb of the penis
Location of the pelvic diaphragm:
-runs vertical
