Exam 3 Pelvis and Perineum

Question 1

The pelvis is divided into the greater and lesser pelvis by the…

What forms this structure?

Answer 1

pelvic brim.

Formed by:

• Sacral promontory
• Sacral ala
• Right and left pubic crest, pectin pubis, and arcuate line of ilium.

Question 2

The pelvic diaphragm forms the…

Answer 2

floor of the pelvic cavity and the roof of the perineum.

Question 3

What is the sacral hiatus and why is it clinically relevant.

Answer 3

Where lamina of S5 do not fuse. Administration site for caudal anesthesia.

Question 4

Parts of the sacrum:

• Sacral promontory
• Ala of sacrum
• Anterior sacral foramina

Answer 4

• Sacral promontory: projection of S1 at anterior midline. Point of reference to make sure pelvis large enough for vaginal birth.
• Ala of sacrum: wings of S1. Articulates with os coxae
• Anterior sacral foramina: larger than posterior sacral foramina. Anterior rami exit here.

Question 5

The ox coxae is formed by what three bones? Where do they meet?

Answer 5

• Ilium, ischium, pubis
• Meet at acetabulum

Question 6

Ilium

• What is it?
• Parts

Answer 6

• Forms superior and lateral part of hip bone
• Parts: Body
  
  • Ala: contains
    
    • Iliac fossa
    • Iliac crest: rim between ASIS and PSIS
    • Arcuate line: Inferior to iliac fossa
    • Greater sciatic notch

Question 7

Ischium

• What is it?
• Parts

Answer 7

• Forms posterior part of coxal bone. Contributes to obturator foramen
• Parts:
  
  • Body
    
    • Ischial spine
    • Ischial tuberosity
    • Lesser sciatic notch
  • Ramus: joins inferior pubic ramus to form ischiopubic ramus

Question 8

What form the greater and lesser sciatic notch?

Answer 8

• The sacrotuberous ligament closes the notches to form foramen.
• The sacrospinous ligament divides foramen into greater and lesser sciatic foramen

Question 9

What passes through the greater sciatic notch?

Answer 9

• Piriformis m
• Superior and inferior gluteal artery, vein, and nerve
• Sciatic nerve
• Internal pudendal artery and vein
• Pudendal nerve

Question 10

What passes through the lesser sciatic foramen?

Answer 10

• Internal pudendal artery and vein
• Pudendal nerve
• Tendon of obturator internus

Question 11

Pubis

• What is it?
• Parts?

Answer 11

• Forms anterior part of coxal bone.
• Parts:
  
  • Body
    
    • Articulates with other pubic body via pubic symphysis
  • Superior ramus
    
    • Contributes to acetabulum
  • Inferior ramus
    
    • Contributes to obturator foramen and ischiopubic ramus

Question 12

What does the greater pelvis contain?

Answer 12

Abdominal viscera

Question 13

What does the lesser pelvis contain?

Answer 13

Pelvic viscera

Question 14

The inferior muscular pelvic aperture is closed off by what?

What is the purpose of these structures?

Answer 14

• Pelvic diaphragm
• Urogenital diaphragm
• Prevent prolapse of bladder, vagina, uterus, and rectum

Question 15

What are the muscles of the lesser pelvis?

Answer 15

• Piriformis
• Obturator internus
• Pelvic diaphragm
  
  • Levator ani
  • Coccygeus

Question 16

What are the parts of the levator ani?

What is their function?

Answer 16

• Puborectalis: Medial portion, thicker and narrow. Forms sling around anorectal junction for fetal continence.
• Pubococcygeus: Intermediate portion. Wider but thinner than puborectalis
• Iliococcygeus: Posterolateral portion. Thinnest part.

Question 17

Perineum

Parts

Boundaries

Answer 17

• Diamond shaped region made up by urogenital triangle and anal triangle.
• Boundaries:
  
  • Anterior: Pubic symphysis
  • Anterolateral: Ischiopubic rami
  • Lateral: Ischial tuberosities
  • Posterolateral: Sacrotuberous ligaments
  • Posterior: Inferior sacrum and coccyx
  • Superior: Inferior aspect of pelvic diaphragm

Question 18

Ischioanal fossa

• What is it?
• Boundaries

Answer 18

• Large, wedge-shaped spaces b/w sking of anal region and inferior surface of pelvic diaphragm. Contains fat, tough fibrous bands of CT, and neurovasculature of inferior rectal region.
• Boundaries:
  
  • Lateral: Ischium and obturator internus
  • Medial: anal canal, external anal sphincter, and inferior surface of levator ani
  • Posterior: sacrotuberous ligament and gluteus maximus
  • Anterior: body of pubic bones
  • Base: perianal skin
  • Apex: where levator ani muscle arises from obturator fascia

Question 19

Pudendal Canal

• Where is it?
• Contents

Answer 19

• Posterior border of ischioanal fossa through lesser sciatic notch to posterior edge of perineal membrane.
• Contents: Internal pudendal vessels
  
  • Pudendal nerve: S2,3,4 (supplies external anal sphincter and perianal skin)

Question 20

Penis

• What is its anatomical position?
• What are its parts?

Answer 20

• Anatomical position is in the erect state.
• Parts:
  
  • Body: Pendulous portion suspended from pubic symphysis by suspensory ligament.
    
    • No muscles covering it.
  • Root: Attached portion in superficial perineal pouch
    
    • Contains bulb and crura of penis
    • Covered by muscles

Question 21

Corpus spongiosum

• Function
• Location
• Parts
• Covering

Answer 21

• Erectile tissue
• Located along ventral midline of body of penis
• Parts:
  
  • Glans - distal expanded end that extends over corpora cavernosa.
    
    • Contains external urethral orifice
  • Surrounds spongy urethra
• Completely surrounded by tunica abluginea penis

Question 22

Corpora cavernosa

• Function
• Location
• Covering

Answer 22

• Paired erectile tissue
• Located laterally and dorsally in body of penis
• Surrounded by tunica albuginea
  
  • Incompeltely separated by fenestrated septum to allow for bilateral erection event

Question 23

Layers of the penis from superficial to deep

Answer 23

• Skin
  
  • Prepuce (foreskin): covers corona and neck of glans
  • Frenulum of prepuce: median fold that connects prepuce to body of penis
• Dartos fascia: not at glans of penis
• Buck’s fascia: binds corpora cavernosa and corpus spongiosum together
• Tunica albuginea
• Erectile tissue

Question 24

Scrotum

• Layers of the scrotum from superficial to deep.
• Arterial supply
• Innervation
• Lymphatics

Answer 24

• Layers:
  
  • Skin
  • Dartos fascia and muscle: allows for retraction of scrotum for thermoregulation
• Arterial supply: Anterior scrotal a (off external pudendal a)
  
  • Posterior scrotal a (off internal pudendal a)
• Innervation: Anterior scrotal n (off ilioinguinal n)
  
  • Posterior scrotal n (off pudendal n)
• Lymphatics drain into superficial inguinal lymph nodes

Question 25

Testes

• Function
• What is it composed of?
• Layers from superficial to deep.

Answer 25

• Produce sperm and male hormones (primarily testosterone)
• Composed of seminiferous tubules
• Layers:
  
  • Parietal layer of tunica vaginalis
  • Visceral layer of tunica vaginalis
  • Tunica albuginea

Question 26

Spermatic cord

• Layers from superficial to deep
• Contents and their function

Answer 26

• Layers:
  
  • External spermatic fascia
  • Cremasteric muscle and fascia
  • Internal spermatic fascia
• Contents:
  
  • Ductus deferens: conveys sperm from epididymis to ejaculatory duct
  • Testicular artery: arises from abdominal aorta to supply testis and epididymis
  • Testicular vein: starts out as pampiniform plexus
    
    • Pampiniform plexus: surrounds testicular artery to cool blood before it reaches testis
  • Internal spermatic plexus (sympathetic nerves)
  • Genital branch of genitofemoral nerve
  • Lymph nodes drain into R/L lumbar nodes

Question 27

The vulva includes:

Answer 27

• Mons pubis
• Labia majorum
• Labia minorum
• Clitoris
• Bulb of vestibule
• Greater vestibular gland
• Lesser vestibular gland

Question 28

Labia majorum

• Function
• Parts
• Contents

Answer 28

• Function: protect urethral and vaginal orifices
• External folds are pigmented, have pubic hair and sebaceous glands.
  
  • Internal folds are pink, smooth, and hairless
• Filled with loose CT, smooth muscle, and termination of round ligament of uterus

Question 29

• Where do the labia majora join anteriorly?
• Where do the labia majora join posteriorly? What is so special about this junction?

Answer 29

• Anterior labial commissure
• Posterior labial commissure
  
  • Dissappears after 1st vaginal birth

Question 30

Labia minora

• Function
• Features

Answer 30

• Surrounds vestibule of vagina
• Rounded folds of skin that are fat-free and hairless
  
  • Frenulum (fourchette) of labia minora: where labia minora meet posteriorly
  • Forms frenulum of clitoris
  • Forms prepuce of clitoris

Question 31

Clitoris

• Parts and their features

Answer 31

• Body: covered by prepuce
• Root:
  
  • composed of 2 crura attached to ischiopubic rami
    
    • Composed of corpora cavernosa
    • Covered by ischiocavernous muscle

Question 32

What two structures are contained within the vestibule of the vagina?

Answer 32

• External urethra orifice
• Vaginal orifice
  
  • Contains greater vestibular glands (Bartholin glands)
  • Contains lesser vestibular glands (Skene’s glands)

Question 33

Arterial supply and innervation of labia

Answer 33

• Anterior labial nerve: branch of ilioinguinal n
• Posterior labial nerve: branch of pudendal n
• Anterior labial artery: branch of external pudendal a
• Posterior labial artery: branch of internal pudendal a

Question 34

Superficial dorsal vein of penis

• Where is it located?
• Where does it drain?

Answer 34

• Located on dorsum of penis between dartos and Buck’s fascia.
• Drains into external pudendal veins

Question 35

Deep dorsal vein of penis/clitoris

• Where is it located?
• What does it drain?
• Where does it drain?

Answer 35

• Located between Buck’s fascia and tunica albuginea
• Drains erectile tissue
• Drains into prostatic venous plexus in males/vesicle venous plexus in females

Question 36

Dorsal artery of penis/clitoris

• Where does it arise from?
• Where is it located?

Answer 36

• Arises from internal pudendal artery in deep perineal pouch
• Runs on either side of deep dorsal vein on dorsum of penis/clitoris
  
  • Deep to Buck’s fascia

Question 37

Dorsal nerve of penis/glans

• Where is it located?
• What does it supply?

Answer 37

• On dorsum of penis/clitoris lateral to dorsal artery of penis/clitoris
  
  • Deep to Buck’s fascia
• Supplies skin and glans

Question 38

Urogenital triangle

• Boundaries
• Function
• Parts
• Layers

Answer 38

• Stretches between pubic arch and terminates at ischial tuberosities
  
  • Anterior portion of inferior pelvic aperture
• Provides support for erectile tissue and urogenital hiatus of pelvic diaphragm via perineal membrane
• Divided into superficial and deep perineal pouches
• Layers:
  
  • Skin: contains external genitalia
  • Superficial fatty layer: continuous with Camper’s fascia and ischioanal fossa fat
  • Colles’ fascia: continuous with Scarpa’s fascia
  • Superficial perineal pouch
  • Perineal membrane
  • Deep perineal pouch
  • Inferior surface of pelvic diaphragm

Question 39

Where does Colles’ fascia attach?

Why is this clinically relevant?

Answer 39

• Continuous with dartos fascia over penis and scrotum in males
• Continous with Scarpa’s fascia
• Attaches to perineal membrane at posterior border of urogenital triangle
• Attaches laterally to ischiopubic rami
• Can allow infection to spread to anterior abdominal wall from UG triangle

Question 40

Superficial male perineal pouch

• Contents

Answer 40

• Root of penis
• Crura of penis
• Bulb of penis
• Spongy urethra

Question 41

Crura of penis

• What is it?
• Where does it run and attach?
• Coverings

Answer 41

• Erectile tissue in root of penis continous with corpora cavernosa
• Run laterally to attach to ischiopubic rami anterior to ischial tuberosities
• Covered by ischiocavernous muscles

Question 42

Bulb of penis

• What is it?
• Where does it run?
• Covering and function

Answer 42

• Erectile tissue in root of penis that is continuation of corpus spongiosum
• Enlarged posterior portion at the midline pierced by spongy urethra.
• Covered by bulbospongiosus muscle

Question 43

Vestibular bulbs

• What are they?
• Where are they located?
• Covering

Answer 43

• Paired erectile tissue
  
  • Homologous with bulb of penis
• On either side of vaginal orifice
• Covered by bulbospongiosus muscle

Question 44

Superficial female perineal pouch

• Contents

Answer 44

• Vestibular bulb
• Crura of clitoris
• Greater vestibular gland
• Lesser vestibular gland

Question 45

Superficial perineal pouch in both sexes

• Contents

Answer 45

• Ischiocavernous muscle
  
  • Force blood from crura into distal parts of corpora cavernosa to maintain an erection.
  • Compress venous outflow
• Bulbospongiosus muscle
  
  • Compress venous outflow
  • Assist in erection similar to ischioacavernous m
  • Constricts to asist in emptying of urine or ejactulate from bulb of penis
• Superficial transverse perineal muscle
  
  • Act as crossbeams to stabilize superficial perineal pouch and provide a firmer base for penis during erection
• Perineal artery
• Superficial perineal nerve
• Deep perineal nerve
• Gallaudet’s fascia (deep investing perineal fascia)

Question 46

Perineal membrane

• What does it separate?
• Features

Answer 46

• Separates superfical and deep perineal pouch (roof of superficial, floor of deep)
• Pierced by urethra in males; urethra and vagina in females
• Anterior defect allows deep dorsal vein of penis/clitoris to drain into pelvis
  
  • Also allows passage of cavernous nerves

Question 47

Perineal body

• What is it?
• What muscles converge here?

Answer 47

• Mass of CT and muscle that acts as central point of perineum
• Converging muscles:
  
  • Bulbospongiosus
  • Superficial transverse perineal
  • Deep transverse perineal
  • External urethral sphincter
  • Levator ani
  • External anal sphincter
  • Muscular portion of rectum

Question 48

Deep perineal pouch

• Boundaries
• Contents

Answer 48

• Boundaries:
  
  • Floor: Perineal membrane
  • Roof: Inferior surface of pelvic diaphragm
  • Lateral: Obturator internus
• Contents:
  
  • External urethral sphincter
  • Deep transverse perineal muscles
  • Bulbourethral glands (males only)
  • Dorsal artery and nerve of penis
  • Anterior recess of ischioanal fossa

Question 49

Deep transverse perineal muscle

• Where is it located?
• What usually happens to this muscle in females?

Answer 49

• Superior to perineal membrane
• Runs transversely from ischial tuberosity and ramus to median raphe and perineal body
• Usually replaced by smooth muscle in females

Question 50

Bulbourethral (Cowper’s) Glands

• Where are they located?
• What are their function?

Answer 50

• Embedded in muscles of deep perineal pouch in males only
  
  • Ducts pierce through perineal membrane into spongy urethra
• Secrete non-viscous material into urethra before and during ejaculation (pre-cum)

Question 51

Urogenital diaphragm

• What makes it up?
• What is its purpose?

Answer 51

• Made up by:
  
  • Perineal membrane
  • External urethral sphincter
  • Deep transverse perineal muscle
  • Superior fascia of UG diaphragm
• Provides addition support to UG hiatus of pelvic diaphragm and strucutres passing through this hiatus

Question 52

Differences between male and female urethra.

Parts of the male urethra.

Answer 52

• The female urethra is shorter in length than the male urethra. The male urethra is also more mobile than the female urethra.
• Parts of the male urethra:
  
  • Intramural: short part from neck of bladder to prostate. Surrounded by internal urethral sphincter.
  • Prostatic: within prostate gland. Site of entrance of secretions from prostate and seminal vesicles and sperm (via ejaculatory ducts)
  • Membranous (intermediate): narrowest part of urethra (most easily ruptured). Surrounded by external urethral sphincter.
  • Spongy: Longest and most mobile portion. Receives substances from bulbourethral glands.
    
    • Enlarges as navicular fossa in glans of penis

Question 53

Rupture of Intermediate Urethra

• How can it happen?
• Where can fluid escape to?

Answer 53

• Occurs from fracture of pelvic girdle above perineal membrane.
• Urine and blood flow into deep perineal pouch and can pool subperitoneally

Question 54

Rupture of Spongy Urethra

• Where does it usually occur?
• Where can fluid accumulate?

Answer 54

• Occurs in bulb of penis
• Urine and blood can escape into superficial perineal pouch and pool in:
  
  • Scrotum: deep to dartos fascia
  • Around penis: deep to dartos fascia
  • Inferior anterior abdominal wall: deep to scarpa’s

Question 55

What are the branches of the internal pudendal artery?

What do they supply?

Answer 55

Branches:

• Inferior rectal a: Supplies inferior portion of anal canal, anal sphincters, perianal skin
• Perineal a: Supplies muscles of superficial pouch and scrotum/vestibule
• Dorsal a of the penis/clitoris: run on eitehr side of deep dorsal vein. Travels in deep perineal pouch
• Deep (central) a of the penis/clitoris: Supplies corpora cavernosa of penis. Primary artery for erection. Branches in deep perineal pouch
• Artery of the bulb: Supplie corpus spongiosum. Branches within deep perineal pouch

Question 56

Lymphatics of the perineum.

• Where do skin and subcutaneous tissue drain?
• Where do deep structures drain?

Answer 56

• Superficial inguinal nodes
• Deep inguinal nodes

Question 57

Pudendal nerve

• Which spinal cord levels
• Fiber types contained in this

Answer 57

• S2,3,4 (keeps the penis off the floor)
• Fiber types: Somatic sensory
  
  • Somatic motor
  • Postganglionic sympathetic

Question 58

Branches of the pudendal nerve and what they supply

Answer 58

• Inferior rectal nerve: Supplies external anal sphincter and perianal skin
• Perineal nerve: Branches into:
  
  • Superficial perineal nerve: Supplies skin and subcutaneous tissue -> posterior scrotal/labial nn
  • Deep perineal nerve: Supplies structures in both superficial and deep perineal pouches
• Dorsal nerve of penis: Supplies skin and glans

Question 59

Cavernous nerves

• What type of fibers are in these?
• What is their function?

Answer 59

• Parasympathetic fibers via pelvic splanchnic nerves -> inferior hypogastric plexus -> pelvic plexus
• Stimulates uncoiling and vasodilation of helicine arteries in corpora cavernosa/vaginal secretions. Causes erection in males.

Parasympathetics “point.” Sympathetics “shoot.” (via pelvic plexus)

Question 60

What crosses the ureter in

• Males
• Females

Answer 60

• Males: Ductus deferens (over ureter)
• Females: Uterine artery (over ureter)

Question 61

When the bladder distends, where does it move into?

What is the purpose of the internal urethral sphincter?

Answer 61

• Moves into extraperitoneal tissue b/w peritoneum and anterior abdominal wall into greater pelvis
• Internal urethral sphincter is only found in males and prevents the retrograde flow of semen into the bladder during ejaculation.

Question 62

Parts of the urinary bladder.

Answer 62

• Apex: Attached to anterior abdominal wall by median umbilical ligament
  
  • Points to superior edge of pubic symphysis
• Fundus: Opposite apex of convex of posterior wall
• Body: Closely related to vagina in females, rectum in males
• Neck: Converging point of fundus and inferolateral portion

Question 63

Detrusor muscle

What is it?

What is the Trigone?

Answer 63

• Internal muscle composing most of wall of bladder
• Trigone: area of detrusor muscle between 2 uretral orifices (connected by interureteric fold) and 1 internal urethral orifice.

Question 64

Rectum

• Where does it begin?
• External features
• Internal features
• Where does it end?

Answer 64

• Begins at rectosigmoidal junction: anterior to S3
• External features: Tenia coli spread out and form complete layer of longitudinal muscle
  
  • No epiploic appendages
  • Sacral flexure: goes from anterior-posterior
  • Perineal flexure: @ anaorectal junction; supported by puborectalis muscles of levator ani (fecal continence)
• Internal features:
  
  • 3 internal folds at lateral curves = transverse rectal folds
• Ends at anorectal junction anterior to tip of coccyx
  
  • Terminal ampulla dilated and supported by levator ani

Question 65

Anal canal

• Where does it begin?
• Where does it end?
• How is it oriented?
• Internal features

Answer 65

• Begins at perineal flexure/anorectal junction
• Ends at anus
• Directed posteriorly and inferiorly
• Internal features:
  
  • Anal columns: mucosal longitudinal folds in superior 1/2 of anal canal
  • Anal valves: flaps of skin at base of anal columns
  • Anal sinus: space superior to anal valves. Anal glands open here
  • Pectinate line: serrated line formed by inferior limit of anal valves. Acts as junction b/w visceral superior anal canal and somatic inferior anal canal

Question 66

Internal anal sphincter

• What is it?
• Where is it located?
• What innervates it?

Answer 66

• Circular muscular coat of rectum
  
  • Thicker below anorectal junction
• Surrounds upper 2/3 anal canal
• Innervated by autonomic nerves
  
  • Sympathetic fibers stimulate contraction
  • Parasympathetic fibers inhibit contraction

Question 67

External anal sphincter

• What are its parts?
• Where is it located?
• What is it innervated by?

Answer 67

• Parts:
  
  • Subcutaneous
  • Superficial
  • Deep
• Surrounds lower 2/3 of anal canal and wraps around internal anal sphincter
• Innervated by inferior rectal branch of pudendal nerve (somatic fibers)

Question 68

What is the difference in neurovasculature of anal canal above and below pectinate line?

Answer 68

Above pectinate line:

• Superior rectal arteries
• Superior rectal veins
• Internal iliac lymph nodes
• Autonomic innervation (sensitive to stretch only)

Below pectinate line:

• Inferior rectal arteries
• Inferior rectal veins
• Superficial lymph nodes
• Somatic innervation (inferior rectal nerves); (sensitive to pain, touch, temperature)

Question 69

Internal hemerrhoids

• What are they?
• What causes them?
• How do they present?
• Where do they occur?

Answer 69

• Prolapsed rectal mucosa: contains veins of internal rectal venous plexus
• Can prolapse into anal canal and become strangulated b/w anal sphincters
• Bleeding is bright red and not typically painful
• Occur above pectinate line

Question 70

External hemorrhoids

• What are they?
• How do they present clinically?
• Where do they occur?

Answer 70

• Thromboses or blood clots in veins of external rectal venous plexus covered by skin
• Often painful due to somatic innervation
• Occur below pectinate line

Question 71

Pathway sperm take from testis to external environment

Answer 71

• Testis
• Epididymis (seminiferous tubule -> mediastinum/rete testis -> efferent ductules)
• Ductus deferens
• Seminal vesicle
• Ejaculatory duct
• Prostate
• Urethra

Question 72

Internal structures of testis

Answer 72

• About 300 lobules with 1-4 seminiferous tubules
• Seminiferous tubules -> straight tubules (about 25)
• Straight tubules -> rete testis in mediastinum
• Rete testis -> 15-25 efferent ductules
• Efferent ductules -> epididymis

Question 73

Epididymis

Components

Location

Answer 73

• Tube: ~6m
• Duct: Thicker as it approaches ductus deferens
• Adherent to superior pole of testis

Question 74

Ductus deferens

• Function
• What is it?
• Location
• Parts

Answer 74

• Conveys sperm from epididymis to ejaculatory duct
• Continuation of duct of epididymis
• Ascends through inguinal canal (through spermatic cord) and runs subperitoneal over external iliac aa and lateral wall of pelvis
  
  • Crosses superior to ureter and superior to seminal vesicle, then medial as it enters prostatic urethra
• Ampulla: enlargement prior to terminating in ejaculatory duct

Question 75

Seminal vesicles

• Function
• Location
• What does it form?

Answer 75

• Produces seminal fluid
• Between fundus of bladder and rectum; lateral to ampullae of ductus deferens; superior to prostate, inferior to ureters
• Merge with ductus deferens to form ejaculatory duct

Question 76

Ejaculatory duct

• What forms it?
• Where is it located?
• Where does it empy?

Answer 76

• Formed by ductus deferens and seminal vesicles
• Located near neck of bladder and travels trhough prostate gland
• Empties into prostatic urethra via small openings on seminal colliculus (below prostatic utricle)

Question 77

Prostate

• Location
• Parts

Answer 77

• Between neck of bladdera nd perineal membrane
  
  • part of deep perineal pouch
  • Posterior surface related to rectum
• 5 lobes
  
  • 2 lateral lobe: major portion of gland; separated by prostatic urethra
  • Median lobe: Between 2 ejaculatory ducts and urethra; most common site of hypertrophy with age
  • Anterior lobe: anterior to urethra
  • Posterior lobe: inferior to ejaculatory duct; palpable via rectum; frequent site of cancer and enlargement
• Prostatic ducts open into prostatic sinus on either side of seminal colliculus

Question 78

Pelvic peritoneum in males

• What does it cover
• What are its pouches and fossas?

Answer 78

• Covers superior and lateral surfaces of pelvic organs
• Pararectal pouches: on either side of upper 1/3 of rectum
• Paravesical pouches: at anterior surface of middle 1/3 of rectum by bladder
• Supravesical fossa: Located superior to anterior apex of bladder. Elevates when bladder fills.
  
  • Site of suprapubic catheter insertion
• Rectovesical pouch: Descends from fundus of bladder and reflects superior to middle 1/3 of rectum
  
  • lowest region of peritoneal cavity when standing. Site of pooling of fluid in peritoneal cavity when standing

Question 79

Ovary

• Function
• Associated ligaments

Answer 79

• Produces oocyte and expels it into peritoneal cavity
• Proper ligament of ovary: attaches ovary to uterus
• Suspensory ligament of ovary: Ridge of peritoneum over ovarian vessels, lymphatics, and nerves as they travel to ovary from posterior abdominal wall

Question 80

Uterine tubes

• Function
• Parts

Answer 80

• Conducts oocyte to uterus
• Parts:
  
  • Infundibulum: funnel shaped lateral portion associated with ovary
  • Fimbriae: finger-like projections into peritoneal cavity that conduct ova into uterine tube
  • Ampullary region: widest and longest part. Site where fertilization happens
  • Isthmus: Narrowest region where enters uterine wall

Question 81

What is a hysterosalpingography?

Answer 81

Scan that determines patency of uterine tubes to determine fertility of woman.

Question 82

What is an ectopic pregnancy? What is the most common type?

Answer 82

Implantation of embryo outside of uterus. Most common type is ampullary region.

Question 83

Uterus

• Parts of the uterus

Answer 83

• Uterine body: Upper 2/3
  
  • Lies on top of bladder; becomes retroverted as bladder fills
• Fundus: Rounded part superior to uterine tubes
• Isthmus: Narrow region b/w body and cervix
• Uterine cervix: Lower 1/3; extends into upper vagina and creates vaginal crevice
  
  • Surrounds external os of uterus
  • Vaginal fornix: surrounds cervix

Question 84

Cervix

• Associated ligaments
• What is parametrium and why is it clinically relevant?

Answer 84

• Cardinal (transverse cervical) ligament: run laterally
• Uterosacral ligament
  
  • Both ligaments make cervix immobile
• Parametrium: surrounds supravaginal cervix and upper vagina.
  
  • Contains uterine a, ureter, and lymphatics
  • Most common site to test for cervical cancer (enlarge lymph nodes)

Question 85

Layers of the uterus

Answer 85

• Perimetrium: Outer layer; is peritoneum
• Myometrium: Middle layer; distends during pregnancy; contains vessels and nerves
• Endometrium: Inner layer; adhered to myometrium; changes thickness due to monthly cycle

Question 86

Positions of the uterus

Answer 86

• Normally within lesser pelvis
• Anteverted: uterine body tipped anterior relative to axis of vagina.
• Anteflexed: uterine body flexed or bent anteriorly to uterine axis

Question 87

Round ligament of the uterus

• Function
• Location

Answer 87

• Tethers uterus
• Passes through inguinal canal
  
  • Anchors to labia majora (can cause pain)

Question 88

Prolapsed Uterus

• What is it?
• What causes it?

Answer 88

• Uterus that has descended into vagina
• Caused by:
  
  • Retroverted uterus
  • Disrupted perineal body
  • Weak or atrophic pelvic muscles and/or ligaments

Question 89

Vagina

• What is it?
• Where and what causes it to collapse?

Answer 89

• Fibromuscular tube connecting vaginal orifice to cervix of uterus
• Typically collapsed toward midline due to compression by rectum and bladder

Question 90

Disadvantages of vagina

Answer 90

• Open connection b/w external environment and internal genitalia and peritoneal cavity can allow the spread of infection.
• The empty tube can allow for prolapse of uterus and/or vagina through vaginal orifice, or bladder through bladder orifice.

Question 91

Vaginal fornices

Answer 91

• Anterior fornix: shallow
• Posterior: deepest fornix. Related to peritoneal cavity and next to rectouterine pouch
• Lateral: shallow anteriorly, deep posteriorly
  
  • Can palpate ovaries and ureters through here

Question 92

Relationships of the vagina

• Anterior
• Posterior

Answer 92

• Anterior
  
  • Urethra
  • Base of bladder
    
    • Cystocele: protrusion of bladder into vagina
• Posterior:
  
  • Anal canal
  • Rectum
    
    • Rectocele: protrusion of rectum into vagina

Question 93

Vaginal fistulas

• Causes
• Possible fistulas

Answer 93

• Causes:
  
  • Gynecelogical surgery
  • Obstetrical trauma
  • Weakness
  • Necrosis
  • Tears of vaginal wall
• Types of fistulas
  
  • Vagina and bladder
  • Vagina and urethra
  • Vagina and rectum
  • Vagina and perineum

Question 94

What is a culdocentesis?

Answer 94

• Aspiration of peritoneal fluid through posterior fornix of vagina.

Question 95

Pelvic peritoneum in females

What are the different recesses and fossas?

What is the clinical significance of rectouterine pouch?

Answer 95

• Covers anterior and lateral surfaces of upper 1/3 of rectum. Covers anterior surface of middle 1/3 of rectum.
  
  • Forms pararectal fossas
• Covers superior surface of bladder.
  
  • Forms supravesical fossa
  • Forms paravesical fossas
• Covers fundus, body, and upper cervix of uterus
  
  • Forms vesicouterine pouch from roof of bladder to anterior wall of uterus
• Runs along posterior wall of uterus and posterior fornix of vagina. Reflects superiorly onto rectum
  
  • Forms rectouterine pouch
    
    • Lowest part in peritoneal cavity when standing
    • Superior to rectovaginal septum
    • Site of fluid pooling in peritoneum when erect
    • Most common site of abdominal pregnancies
    • Site of culdocentesis

Question 96

Broad ligament of uterus

• Function
• What is it?
• Parts

Answer 96

• Connects uterus to lateral walls of pelvis.
• Reflection of peritoneum over uterus and uterine tube
  
  • Free edges at fimbriae to open them into periotneal cavity
• Parts:
  
  • Mesovarium: Mesentery of ovary
  • Mesosalpinx: Mesentery uterine tube
  • Mesometrium: Mesentery of uterus
  • Perimetrium: Covers uterine body and fundus

Question 97

Pelvic fascia

• What is it?
• Where is it located?
• What are its two types?

Answer 97

• Connective tissue
• Occupies pelvic spaces b/w parietal peritoneum and pelvic floor (not occupied by pelvic organs)
• Two types are:
  
  • Membranous
  • Endopelvic

Question 98

Membranous pelvic fascia

• Parietal layer
  
  • What does it line?
• Visceral layer
  
  • What does it line?
• What do they form when they come together?

Answer 98

• Parietal layer
  
  • Lines pelvic aspect of:
    
    • Obturator internus
    • Piriformis
    • Coccygeus
    • Levator ani
    • Portion of sphincter urethrae muscles
• Visceral layer:
  
  • Directly ensheaths pelvic organs
• Forms tendinous arch of pelvic fascia where pelvic viscera penetrate the pelvic floor

Question 99

What are the different parts of the tendinous arch of pelvic fascia? What do they connect?

Answer 99

• Puboprostatic: connects prostate to pubis
• Pubovesical (pubocervical): connects neck of bladder to pubis
• Sacrogenital (uterosacral): connects sacrum and prostate in males/connects sacrum and vagina in females

Question 100

Endopelvic fascia

• Where is it located?
• What is its function?
• What are its 2 types?

Answer 100

• Between parietal and visceral membrane layers of pelvic fascia
• Acts as packing material by forming CT matrix
• 2 types
  
  • Loose
  • Condensed

Question 101

Loose areolar (fatty) endopelvic fascia

• What does it contain?
• What does it form in the female?
• What spaces does it fill?

Answer 101

• Contains only minor lymphatics and nutrient vessels
• Forms parametrium in female
• Fills:
  
  • Retropubic (prevesical) space
  • Rectrorectal (presacral) space
  • Pararectal space
  • Paravesical space

Question 102

Condensed endopelvic fascia

• What larger structure does it form?
• What are the subdivisions of this larger structure?
• What do these subdivisions contain?
• Where are these subdivisions?

Answer 102

• Forms hypogastric sheath
• Divisions of hypogastric sheath:
  
  • Lateral ligament of bladder: contains superior vesical a/v
  • Presacral fascia: contains middle rectal a/v
    
    • Passes to rectum
  • Rectovesical septum: conatins arteries to bladder, prostate, and rectum
    
    • In males only
    • Between fundus of bladder and prostate and rectum
  • Transverse cervical ligament (Cardinal): contains uterine a/v
    
    • In females only
    • Passive support of uterues from cervix to pelvic wall

Question 103

Where does the aorta bifurcate?

What does it birfucate into?

What does this bifurcate into?

Answer 103

• Bifurcates at L4
• Divides into common iliac arteries
• Divide into internal and external iliac aa at IV disc b/w L5 and S1

Question 104

What are the branches of the internal iliac artery?

Where do they run?

What do they supply?

Answer 104

Posterior division:

• Iliolumbar: Runs superiorly out of lesser pelvis to iliac fossa
• Lateral sacral: Passes through sacral foramen
  
  • Supplies skin and muscles over sacrum and spinal meninges
• Superior gluteal: Passes to gluteal region b/w lumbosacral trunk and S1. Passes superior to piriformis

Anterior division:

• Inferior gluteal: Runs b/w S2 and S3. Passes inferior to piriformis
• Internal pudendal: Passes inferior to piriformis
  
  • Supplies perineum and external genitalia
• Obturator: Runs along obturator fascia on lateral wall of pelvis antero-laterally.
  
  • Supplies medial thigh
• Middle rectal: Runs through anorectal canal.
  
  • Anastomoses with superior and inferior rectal arteries
• Inferior vesical: Typically only in males (vaginal a in females)
  
  • Passes to fundus of bladder and seminal vesicles to supply bladder
• Uterine: In females only
  
  • Passes directly superior to ureter near lateral fornix of vagina
  • Supplies placenta during pregnancy; supplies uterus
• Umbilical: Passes superior and lateral to bladder
  
  • gives rise to superior vesical aa
  • Forms medial umbilical ligament

Question 105

Lymphatics of lesser pelvis:

What are the 4 main groups of lymph nodes and what region do they receive their lymph from?

Answer 105

• External iliac: receive lymph from inguinal nodes
• Internal iliac: receive lymph from pelvic viscera and gluteal region
• Sacral: receive lymph from posteroinferior pelvic viscera
• Common iliac: receives lymph from external iliac, internal iliac, and sacral lymph nodes.
  
  • Drains to lumbar nodes

Question 106

Veins of the lesser pelvis

1. What unique structures form around pelvic viscera?
2. What do these structures drain into?
3. What do these drain into?
4. What do these structures drain into?

Answer 106

• Pelvic venous plexus around pelvic viscera (ex prostatic venous plexus)
• Drain into internal iliac vein
• Drain into common iliac vein
  
  • Unite a level L5
• Drain into IVC

Question 107

Ilioinguinal nerve

• What spinal level supplies it?
• What does it innervate?

Answer 107

• L1
• Supplies skin of mons pubis
  
  • Anterior scrotum/labia majora

Question 108

Genitofemoral nerve

• What spinal cord levels supply this?
• What does it innervate?

Answer 108

• L1,2
• Cremaster muscle
  
  • Skin anterolateral scrotum/labia majora

Question 109

Femoral nerve

• What spinal cord level supplies this?
• What does it innervate?

Answer 109

• L2,3,4
• Innervates iliopsoas muscle

Question 110

Obturator nerve

• What spinal cord supplies this?
• What does it innervate?

Answer 110

• L2,3,4
• Innervates medial thigh
  
  • Does NOT innervate structures of true pelvis

Question 111

Lumbosacral trunk

• What spinal cord levels supply this?
• What does it join?
• What does it innervate?

Answer 111

• L4-L5
• Joins sacral plexus
• Innervates lower limb

Question 112

Nerve to Levator ani/coccygeus

• What spinal cord levels supply this?
• What does it innervate?
• What is it part of?

Answer 112

• S3-S4
• Levatora ani/coccygeus
• Sacral plexus

Question 113

Nerve to piriformis

• What spinal cord levels supply this?
• What does it innervate?
• What is it a part of?

Answer 113

• S1,2
• Innervates piriformis
• Part of sacral plexus

Question 114

Pudendal nerve

• What spinal cord levels supply this?
• What does it innervate?
• What is it part of?

Answer 114

• S2,3,4
• Main nerve supplying perineum
• Sacral plexus

Question 115

Posterior femoral cutaneous nerve

• What spinal cord levels supply this?
• What does it supply?
• What is it part of?

Answer 115

• S1-S3
• Supplies lateral perineal skin
• Part of sacral plexus

Question 116

Superior hyopgastric plexus

• What is it a continuation of?
• Where is it located?
• What kind of nerve fibers are found in this?

Answer 116

• Continuation of aortic plexus
• Located below bifurcation of aorta
• Composed of:
  
  • Preganglionic sympathetics (via lumbar splanchnic nerves)
  • Postganglionic sympathetics
    
    • Microganglia within plexus site of synapse
  • Visceral afferents
  • NO PARASYMPATHETICS

Question 117

Inferior hypogastric plexuses

• Where is it located?
• What type of nerve fibers compose this?

Answer 117

• Located at bifurcation of superior hypogastric plexus near level of sacral promontory
  
  • Paired (right and left)
• Contain:
  
  • Preganglionic sympathetic
  • Postganglionic sympathetic (primary)
  • Preganglionic parasympathetic (via pelvic splanchnic)
  • Visceral afferents

Question 118

Pelvic plexuses

• Where are they located?
• What are the different types?
• What nerve fibers constitute this?

Answer 118

• Embedded in pelvic fascia and covering pelvic viscera
• Types in male: prostatic, vesical, rectal
• Types in female: vesical, uterovaginal, rectal
• Nerve fiber types:
  
  • Visceral afferents
  • Postganglionic sympathetics
  • Preganglionc parasympathetics

Question 119

Pelvic splanchnics

• What spinal cord levels supply these?
• What type of nerve fibers constitute these?
• What do they merge with?
• What do they supply?

Answer 119

• Ventral rami S2,3,4
• Nerve fiber type: preganglionic parasympathetic fibers
• Merge with inferior hypogastric plexuses and pelvic plexuses
• Supply:
  
  • All pelvic viscera
  • Erectile tissue of perineum (via cavernous nerves)
  • Abdominal viscera that are supplied by IMA
    
    • Descending and sigmoid colon (via ascending parasympathetic fibers from pelvic plexus/inferior hypogastric plexus)

Question 120

Sacral sympathetic trunk

• What is it a continuation of?
• What does it form when it merges? Where does it merge?
• What type of rami communicantes is present?

Answer 120

• Continuation of lumbar sympathetic trunk
  
  • Sends sympathetics to lower limb
• Forms ganglion impar in front of coccyx when it merges
• Gray rami communicantes present here only

Question 121

Autonomic function of sympathetic fibers in pelvis:

Answer 121

• Vasoconstriction
• Inhibit peristalsis of rectum
• Constrict involuntary sphincters (internal anal, internal urethral)
• Stimulate contraction of internal genital organs (ejaculation)

Question 122

Autonomic function of parasympathetics in pelvis:

Answer 122

• Increase peristalsis of rectum
• Inhibit constriction of involuntary sphincters
• Stimulate contraction of detrussor muscle of bladder
• Erection

Question 123

Visceral reflex afferents

• How do they travel back to spinal cord?
• Which levels do they go to?

Answer 123

• Travel retrograde with parasympathetics
• To S2,3,4

Question 124

Visceral pain afferents

• What organs do they come from?
• How do they travel back to spinal cord?
• What spinal cord level do they go to?

Answer 124

• Come from:
  
  • Organs covered in peritoneum
    
    • Travel retrograde with sympathetics
    • To level T11-L1
  • Subperitoneal organs
    
    • Travel retrograde with parasympathetics
    • To dorsal root ganglia S2,3,4

Question 125

Sympathetic innervation of bladder

• Function
• What pathway does it take from the spinal cord to bladder? What nerve fibers are in each step?

Answer 125

• Contraction of internal urethral sphincter in males
• Pathway:
  
  • T11-L2; mostly lumbar splanchnics: preganglionic sympathetics
  • Superior hypogastric plexus: pre or postganglionic sympathetic fibers
  • Inferior hypogastric plexus: pre or postganglionic sympathetic fibers
  • Vesicle plexus: pre or postganglionic sympathetic fibers

Question 126

Parasympathetic innervation of bladder

• Function:
• Pathway from spinal cord to bladder.

Answer 126

• Motor innervation to detrussor muscle of bladder
• Inhibitory to internal urethral sphincter
• Pathway:
  
  • Pelvic splanchnics
  • Inferior hypogastric plexus
  • Vesicle plexus

Question 127

Visceral afferents of bladder

• Function
• Pathway from bladder to spinal cord.
  
  • What is the exception?

Answer 127

• Sensory
• Pathway follows parasympathetic retrograde primarily:
  
  • Vesicle plexus
  • Inferior hypogastric plexus
  • Pelvic splanchnics
  • S2-S4 spinal sensory ganglia
• EXCEPTION: superior surface pathway:
  
  • Vesicle plexus
  • Inferior hypogastric plexus
  • Superior hypogastric plexus
  • T11-L2 spinal sensory ganglia via lumbar splanchnic nerves

Question 128

Somatic innervation of bladder

• Function
• How does it reach bladder?

Answer 128

• Voluntary control of external urethral sphincter
• Via deep perineal nerve of pudendal nerve

Question 129

Sympathetic innervation of vagina and uterus

• Which portion of the vagina does it supply?
• Pathway from spinal cord to vagina and uterus.

Answer 129

• Supplies superior 3/4-4/5 of vagina
• Pathway:
  
  • Lumbar splanchnics
  • Superior hypogastric plexus
  • Inferior hypogastric plexus
  • Uterovaginal plexus

Question 130

Parasympathetic innervation of vagina and uterus

• What portion of vagina does this supply?
• Pathway from spinal cord to vagina and uterus

Answer 130

• Superior 3/4-4/5 of vagina supplied
• Pathway:
  
  • Pelvic splanchnics
  • Inferior hypogastric plexus
  • Uterovaginal plexus

Question 131

Visceral afferents of vagina and uterus superior to pelvic pain line

• What portion of vagina and uterus does it supply?
• What pathway does it follow to spinal cord?

Answer 131

• Supplies fundus and body of uterus and superior 3/4-4/5 of vagina.
• Pathway: follows sympathetics retrograde:
  
  • Uterovaginal plexus
  • Inferior hypogastric plexus
  • Superior hypogastric plexus
  • Lumbar splanchnics to T11-L2 spinal sensory ganglia

Question 132

Visceral afferents of vagina and uterus inferior to pelvic pain line

• What portion of uterues and vagina does it supply?
• Pathway from vagina and uterus to spinal cord.

Answer 132

• Supplies subperitoneal uterus and vagina
• Pathway: follows parasympathetic fibers:
  
  • Uterovaginal plexus
  • Inferior hypogastric plexus
  • Plevic splanchnics
  • S2-S4 dorsal root ganglia

Question 133

Types of anesthesia for childbirth.

Administration site.

What is anesthetized?

• Spinal anesthesia
• Caudal epidural block
• Pudendal block

Answer 133

• Spinal anesthesia: administered at L3-L4.
  
  • Numbs: perineum
  • Pelvic floor
  • Uterus (electronic monitoring of uterine contractions)
  • Birth canal
  • Lower limbs
• Caudal epidural block: administered in sacral canal via sacral hiatus. In-dwelling catheter allows for more administration of anesthesia if necessary.
  
  • Numbs: Birth canal
  • Pelvic floor
  • Majority of perineum
• Pudendal nerve block: administered over S2-S4 dermatomes
  
  • Numbs majority of perineum
  • Inferior vagina

Question 134

Sympathetic innervation of internal male genitalia

• Function
• Pathway from spinal cord to genitalia.

Answer 134

• Stimulate peristaltic contraction of ductus deferens
• Stimulate contraction and secretion form seminal glands and prostate
• Pathway:
  
  • Lumbar splanchnics
  • Superior hypogastric plexus
  • Inferior hypogastric plexus
  • Pelvic plexus

Question 135

Parasympathetic innervation of internal male genitalia

• Function
• Pathway from spinal cord to genitalia

Answer 135

• Cavernous nerves cause erection
• Pathway:
  
  • Pelvic splanchnics
  • Inferior hypogastric plexus
  • Pelvic plexuses

Question 136

What clinical concerns arise from resection of the prostate gland?

Answer 136

• If the cavernouse nerves are damaged during resection, erectile dysfunction may occur. Male can still ejaculate due to intact sympathetic nerve fibers.

Question 137

Parasympathetic innervation of the rectum

• What does it supply?
• Pathway to rectum from spinal cord

Answer 137

• Supplies smooth muscles
• Pathway:
  
  • Pelvic splanchnics
  • Inferior hypogastric plexus
  • Middle rectal plexus

Question 138

Sympathetic innervation to rectum

• What does it supply?

Answer 138

• Supply blood vessels and glands

Question 139

Visceral afferent fibers of rectum

• What do they sense?
• How do they reach the spinal cord?
• How does the emptying reflex reach the spinal cord?

Answer 139

• Senses pain and presence of gas/feces
• Pathway:
  
  • Middle rectal plexus
  • Inferior hypogastric plexus
  • Pelvic splanchnic nerves to S2,3,4
• Emptying reflex via pelvic splanchnic S2,3,4

Question 140

Autonomic innervation of anal canal

• Function of sympathetic fibers
• Function of parasympathetic fibers
• Function and pathway of visceral afferents

Answer 140

• Sympathetic fibers maintain tone of internal sphincter
• Parasympathetic fibers inhibit tonus of intern sphincter and evoke peristalsis and defecation.
• Visceral afferents sensitive to stretch of rectal ampulla (inhibits tonus of internal sphincter)
  
  • Travels retrograde with parasympathetics to dorsal root ganglia of S2,3,4