Pelvis II: Female & Male Pelvis Flashcards
What is apart of the Pelvic Cavity?
- Greater Pelvis
- Superior Pelvic Aperture (Pelvic Brim)
- Lesser Pelvis
- Inferior Pelvic Aperture
Pelvic brim:
separates the GREATER PELVIS rom the LESSER PELVIS
What is apart of the Pelvic Joints?
- Sacroiliac Joints
- Pubic Symphysis
Sacroiliac Joints:
- Transfer weight & stabilize
the bony pelvis (attachment) - Limited mobility
Pubic Symphysis:
Fibrocartilaginous disc
(connect the 2 sides of the pelvis - imp. for childbirth)
What are the major ligaments of pelvis?
- Sacrotuberous Ligament
- Sacrospinous Ligament
- Obturator Membrane
- Obturator Canal
What covers the Obturator Foramen?
Obturator Membrane
What is the passageway for Obturator nerve, Obturator artery, & Obturator vein?
Obturator Canal
(they go to function in adductor compartment)
What are the differences in the Male & Female Pelvises?
Male (Non-Obstetric):
* Bones are heavier and thicker, False pelvis is deep & pelvic cavity is narrow and deep
* Inlet heart-shaped and small & outlet comparably small
* Subpubic angle more acute
* Coccyx less flexible and curved
Female (Obstetric):
* Bones are lighter and thinner, False pelvis is shallow & pelvic cavity is wide and shallow
* Inlet oval and round & outlet comparably large
* Subpubic angle large
* Coccyx more flexible and
straighter
What are the Pelvic Diameters?
True (obstetrical) conjugate
- Sacral promontory → pubic symphysis
- Narrowest FIXED distance (~11.5cm or 4.5”)
Interspinous distance
- btwn ischial spines
- Narrowest part of canal (~10cm or 4”)
- NOT fixed* (will relax a bit b/c of relaxin & sex hormones)
What causes the pelvic joints & ligaments to relax?
Relaxin & Sex Hormones
(in all of body)
(more likely to dislocate during last tri of pregnancy)
What does the Peritoneum overlie?
Overlies the pelvic viscera & fascia
Where is the exception to where the Peritoneum overlies
except the ovaries & uterine tubes
- b/c egg has to move from FT
What is included in the Peritoneal Pelvic Cavity?
- Supravesical Fossae
- Retrovesical Pouch
- Vesicouterine Pouch
- Rectouterine Pouch
(of Douglas)
What are the Pouches in the Peritoneal Pelvic Cavity?
- Retrovesical Pouch (post. to bladder)
- Vesicouterine Pouch
- Rectouterine Pouch
(of Douglas)
What pouches in the Peritoneal Pelvic Cavity are found in males?
- Retrovesical Pouch (post. to bladder)
What pouches in the Peritoneal Pelvic Cavity are found in females?
- Vesicouterine Pouch
- Rectouterine Pouch
(of Douglas)
What are the lowest points in abd. that drains?
- Retrovesical Pouch (post. to bladder) (IN MALES)
- Rectouterine Pouch (IN FEMALES)
(of Douglas)
What is the Pelvic Floor actions?
- Maintains fecal and urinary continence through tonic contraction (always slightly contracted)
- Supports the abdominopelvic viscera
- Resists increases in
intra-abdominal pressure (e.g. coughing, sneezing, liHing heavy objects)
What is the Pelvic Floor formed by?
the pelvic diaphragm
What is the Pelvic Floor composed of?
- Coccygeus muscles
- Levator ani muscles
– Puborectalis (most medial)
– Pubucoccygeus - Iliococcygeus (most lateral)
What does the Levator Ani Muscle leave?
leaves an ANTERIOR GAP, the LEVATOR HIATUS (urogenital hiatus) for the passage of urethra, vagina (females only) and rectum
What does the Puborectalis (a Levator Ani Muscle) do?
Forms a sling around the anorectal junction to maintain the ANORECTAL FLEXURE.
(rectum isn’t straight b/c of this muscle - helps to hold feces; if it was straight it would defecet)
What is the Puborectalis (a Levator Ani Muscle) important for?
Important for maintaining FECAL CONTINENCE.
Which Levator Ani Muscle may be torn or weakened during childbirth?
Pubococcygeus & puborectalis
*13–36% of vaginal deliveries
What is the importance of Pelvic Diaphragm?
- Pelvic Prolapse
– uterus or bladder can prolapse
(females have more prevalence of prolapse over males) - Stress Incontinence
– sagging & weakness of the bladder neck
– urine leaks during a cough or movement
– Kegels can help
Insufficiency of the pelvic floor may cause:
- Problems with defecation
- Problems with micturition
- Uterine descensus
- Pelvic organ prolapse
What are the Ureters?
Muscular tubes that drain urine from the kidneys to the bladder.
Where are the Ureters?
Retroperitoneal
Where do the Ureters cross?
Cross the pelvic brim over the bifurcation of the common iliac arteries
(pass from posterior –> anterior)
How do the Ureters cross in females?
In females, passes directly inferior to the UTERINE ARTERY (imp. landmark if uterus has to be taken out)
“water under the bridge”
How do the Ureters cross in males?
In males, passes DIRECTLY INFERIOR to the ductus deferens
and superior to the seminal vesicles.
How do the Ureters cross in males?
In males, passes INFERIOR to the ductus deferens
and SUPERIOR to the seminal vesicles.
(also pass from posterior –> anterior)
(use gravity - steep; to bring urine down to bladder)
What is the Bladder?
Hollow, distensible structure with strong muscular walls
Where is the Bladder?
Subperitoneal
Suprapubic Cystotomy - way to get a cathetor in, if it can’t go in normal way
What is apart of the female Urethra?
Short, muscular tube
(~4 cm long)
External urethral
sphincter
Internal urethral orifice
(NO internal urethral sphincter)
External urethral orifice
Vestibule of vagina (between labia minora)
What is apart of the male Urethra?
Long, muscular tube
(18-22 cm long)
External urethral orifice
Internal urethral orifice
Prostatic urethra
Membranous urethra
Penile (Spongy) urethra
Prostatic urethra:
W/in anterior prostate
Membranous urethra:
Passes through pelvic diaphragm
Penile (Spongy) urethra:
Located within the corpus spongiosum
Where does the Rectum begin at?
rectosigmoidal junction
Where does the Rectum end at?
anorectal junction at tip of coccyx
What is the inside of the Rectum like?
–> Sigmoid colon
–> Rectosignmoid junction
–> Rectum (Transverse Rectal Folds - S shape – allows feces to stay in here so we don’t void all at the same time)
—> Anorectal Junction
–> Anal Canal
–> Anus
*Change to SMOOTH muscle in rectum
What are the Anal Sphincters?
External Anal Sphincter
- Voluntary
- Inferior rectal
nerve
Internal Anal Sphincter
- Involuntary
- Autonomics from superior rectal plexus
Sympathetics: Stimulate & maintain contraction
Parasympathetics: Relax sphincter
Usually contracted
What is apart of the Female Reproductive Anatomy?
- Uterine tube
- Ovaries
- Uterus
- Cervix (uterus protrudes into top portion of vagina)
- Vagina (lowest organ for repro.)
- Vestibule of Vagina
Where are the Ovaries located?
project posteriorly
Vagina function
- Forms the inferior part of the birth canal
- Receives penis and ejaculate during sexual intercourse.
Musculomembranous tube (7-9 cm long)
What is the Vaginal Fornix?
Posterior
Anterior
Lateral
What is apart of the Uterus?
- Fundus
- Body
- Cervix
- Uterine ostium (opening to fallopian tube)
- Isthmus
- Internal os
- Cervical canal
- External os (see this on exam)
What are the Uterus linings?
Parametrium (peritoneum)
Myometrium (thick muscular)
Endometrium (inner lining)
- Harbouring and nourishing the embryo/ fetus (endometrium and myometrium)
Pap Smear:
Recommended women 21-65
Cervical cancer: ~13,000/year
External Os is checked
What is the position of the Uterus?
Anteverted & Anteflexed
Angle of flexion - tells us where the uterus is sitting
Angle of anteversion - how far over/posterior the uterus is
What is the Binmanual Pelvic Exam?
Performed to determine the size and nature of the uterus and the presence or absence of adnexal masses
What are the Ligaments of the Uterus?
Round ligament of the Uterus
Uterosacral ligaments
Broad Ligament (Peritoneum)
- anchors all around
- like a blanket
What is the order of the Fallopian Tubes?
- Pick-up of ovulated oocytes (infundibulum)
- Transport of the matura>ng oocyte (infundibulum and ampulla)
- Nurishment of oocyte and blastocyst (ampulla)
- Sperm reservoir (isthmus)
What are the Ovaries?
- Secretion of the steroid hormones estrogen and progesterone
- Production of ova(ovarian follicles)
- throw eggs out for FT to catch
The ovary is connected to the uterus by the ______
ovarian ligament
The main blood
supply to the ovary,
the _________,
derives from the abdominal
aorta and reaches the ovary through the suspensory ligament of ovary (clin term: infundibulopelvic ligament).
ovarian artery
The RIGHT OVARIAN vein drains into the __________,
The LEFT OVARIAN veins drains into the __________
inferior vena cava
left renal vein
What are Ectopic Pregnancies?
in wrong place
common in Ampulla where fertilization takes place
Fertilization usually occurs in the _______.
ampulla
Implantation should occur in the ______ of the uterus.
body
What is the male reproductive anatomy?
- Ampulla of ductus deferens
- Ductus (vas) deferens
- Ductus deferens
Where are the Testis located?
in the scrotum
What do the Testis produce?
- produces SPERMATOZOA (seminiferous tubles)
- produces TESTOSTERONE (Leydig cells)
- the tunica vaginalis ensheaths testis and epididymis (encases the structure to avoid herniation)
What is the Ductus (Vas) Deferens?
conducts sperm
- maturation & storage of spermatozoa
What is the Ductus Deferens?
- Long muscular tube
- Connects epididymis to ejaculatory duct
- Traverses the inguinal canal
- Enlarges to ampulla behind the bladder
- Joins seminal vesicle for the
ejaculatory duct
Final site of sperm storage & maturation - ampulla
What is a Vasectomy?
- ~500,000 per year.
- Ductus deferens is double-ligated, and a section removed
What are the Seminal Vesicles?
- Accessory gland
- Produces ~ 80% of seminal fluid
Secrete alkaline fluid - to bulk up the ejaculate, for the internal envir. of female & needs to neutralize urine in the internal male
What is the Prostate?
Secretes prostatic fluid (activates sperm & promotes motility)
- int. envir of females also promotes motility
What is the Ejaculatory Duct?
- largest accessory gland of the male reproductive system
- located below the urinary bladder
- ducts open into the prostaOc part of the male urethra
- prostatic secretions account for 20 – 30% of the ejaculate volume
- secretions are acidic (pH 6.4), serous and milky
What are the Pelvic Arteries?
- Common iliac a.
- Internal iliac a.
- External iliac a.
- Other arteries entering pelvis:
– Testicular/ovarian a.
What is the Posterior & Anterior divisions of the Internal iliac a?
Posterior division
(vessels to pelvic wall and gluteal region)
Anterior division
(vessels to pelvic wall, pelvic viscera, medial thigh and external genitalia)
The ______ of the uterine artery anastomoses with the ____ which brings the main blood supply to the ovary
ovarian branch
ovarian a.
Ureter passes inferior to _____
uterine a.
Prostatic arteries branch off…
inferior vesical, internal pudendal, & middle rectal arteries.
What are the Pelvic Veins?
Ovarian/Testicular Vein
*Right vein drains to IVC and left vein drains to left renal vein
Pelvic venous plexuses –>
Internal Iliac Veins
What are the Pelvic Nerves?
- Sacral Plexus
Lumbosacral trunk (L4-5) & Anterior rami S1-S3 - *Inferior gluteal n.
(L5-S2) - Pudendal n. (S2-S4)
- Lumbosacral trunk (L4-L5)
- Superior gluteal n. (L4-S1)
- Obturator nerve (L2-L4)
- Sciatic nerve (L4-S3)
What is the Pain Innervation?
Follow Sympathetics
to T11-L1/2 spinal sensory ganglia &
spinal cord segments
Pelvic Pain Line Corresponds to lower limit of peritoneum
Follow
Parasympathetics
to S2-S4
spinal sensory ganglia & spinal cord segments
What does the Sympathetic Innervation control?
- Vasoconstriction
- Inhibits peristalsis
- Contracts involuntary
sphincters
(internal anal sphincter &
male internal urethral sphincter) - Ejaculation
- Remission of genital erection
What does the Parasympathetic Innervation control?
Increases peristalsis
Stimulates contraction of detrusor muscle of urinary bladder
Relaxes involuntary sphincters (internal anal sphincter & male
internal urethral sphincter)
Promotes genital erection
Epidural Block:
epidural space L3/4 via indwelling catheter
Anesthetizes cervix, vagina, pelvic floor, & most of perineum
Spinal Block:
subarachnoid space L3/4 via needle
Anesthetizes lower half of body
Above the Pelvic Pain Line:
Pain sensation → T11-L1/2 spinal cord
Pudendal N. Block:
Anesthetizes perineum
Where is the Perineum?
Inferior to the pelvic diaphragm (inferior to the fascia)
UG Triangle?
- External genitalia and perineal membrane
- Perforated for Urethra (Vagina)
Anal Triangle:
- Anus, anal canal and ischioanal fat
- Perforated by anus
Greater Vestibular Glands:
secrete mucus to lubricate the
vagina
Erectile Tissue in the Penis:
Corpora Cavernosa - fill with blood during erection
Corpus Spongiosum - doesn’t fill with blood - need that for urethra to be open
Ischiocavernosus Muscles:
Paired muscles covering the crura of the clitoris/penis
Superficial Transverse Perineal Muscles:
Paired muscles that form a cross beam to stabilize the perineal region
Bulbospongiosus Muscles:
Paired muscles covering the
bulb of the Vestibule/penis
Innervation of Perineal Muscles?
Pudendal n.
help maintain erection in both sexes
What is the innervation of the perineum?
Pudendal nerve
- sensory supply for perineal skin (posterior labial nerves)
- somatic motor nerve for
o external anal sphincter
(inferior rectal nerve)
o external urethral sphincter
o urethrovaginal sphincter
o all perineal muscles
Postganglionic SYMPATHETIC NERVES travel with the pudendal nerves and its cutaneous branches to reach the skin (vasomotor, sweat glands).
Parasympathetic nerves do NOT travel with the pudendal nerve
Where does the Pudenal nerve derive from and contain?
- Derives from S2-S4 spinal cord segments
- Contains fibers from S2-S4 anterior rami of the sacral plexus
Pudendal nerve - Exits the pelvis through the greater sciatic foramen
- Winds around the ischial spine
- Courses through the lesser sciatic foramen to enter the perineum below the pelvic diaphragm Pudendal nerve
Pudendal Nerve Block:
- Anaesthetic administered near ischial spine
- Anaesthesia effective for perineal skin and lower part of vagina
- Not effective for cervix and upper part of vagina
- Mother is aware of uterine contractions and associated pain
- Re-administration is problematic during prolonged birth phase
Erection and Cavernous Nerves pathway:
Parasympathetic fibers –> Pelvic Splanchnic nerves (S2-S4) –> Inferior Hypogastric plexus –> Pelvic plexuses –> Prostatic plexus –> Cavernous nerves
Male Erection:
- PARAsympathetic nerve stimulation (S2-S4)
- HELICINE ARTERIES are dilated
- BULBOSPONGIOSUS & ICHIOCAVERNOSUS muscles COMPRESS erectile tissues
Male Emission/Ejaculation:
- SYMPATHETIC nerve stimulation (IML L1-L2)
- Semen & prostatic fluid is delivered to prostatic urethra
- Closure of internal urethral sphincter
- Contraction of BULBOSPONGIOSUS muscle (DEEP PERINEAL NERVE S2-S4)
Male Remission:
- SYMPATHETIC stimulation (IML L1-L2)
- Constriction of HELICINE ARTERIES
- BULBOSPONGIOSUS & ISCHIOCAVERNOSUS muscles RELAX
Erectile Dysfunction:
Inability to obtain an erection
Erectile Dysfunction causes:
- Central nervous system disorders
- Endocrine disorders
- Lack of nervous stimulation
- Lack of blood vessel dilation
Treatment: Oral medication - Prostatic plexus or cavernous nerve lesion
Treatment: Penile Implants (Pumps/semi rigid rods)
