Trans - Perineum and External Genitalia Flashcards
What is immediately anterior to the perineum?
Pubic symphysis
The ischial tuberosities are located _____ to the perineum
Lateral
The anal canal is found in the
Anal triangle
What encloses the urogenital triangle?
Perineal membrane
Ischiocavernosus: action
Forces blood from cavernous spaces in crura into distal parts of corpora cavernosa
What muscles compress the bulb of the penis and the corpora spongiosum?
Bulbospongiosus
Bulbocavernosus
Aids pelvic diaphragm in supporting pelvic viscera
Superficial transverse perineal muscles
Bartholin’s gland: function
Lubricates vaginal canal by secreting mucus
What is located immediately inferior to the deep perineal space?
Perineal membrane
Most prominent blood vessel in the deep perineal space
Deep dorsal vein of the penis / clitoris
Lubricates and cleanses the urethra during ejaculation
Cowper’s gland
The deep post-anal space is where the ____ communicate
Ischiorectal fossa
Medial boundary of the ischiorectal fossa
External anal sphincter
What nerves are in the ischiorectal fossa?
- Perforating cutaneous branches of S2 and S3
2. Perineal branch of S4
Voluntary sphincter surrounding the inferior 2/3 of the anal canal
External anal sphincter
Prolapse of the bladder and / or uterus is caused by:
Stretching or tearing of the perineal body
Location of the perineal body
Central point of perineum
What four muscles converge at the central point of the perineum?
- Bulbocavernosus
- Superficial transverse perineal
- External anal sphincter
- Levator ani
The central point of the perineum is important because:
It determines whether the surgeon should go medial or mediolateral during an episiotomy
Episiotomy: definition
Surgical incision of perineum and interoposterior vaginal wall performed just prior to delivery to prevent perineal lacerations
This type of episiotomy heals faster
Medial
Episiotomy in which muscles are severed
Mediolateral
Why are mediolateral episiotomies done?
If the length of the perineal body is less than 3mm, a mediolateral episiotomy must be performed to prevent complications
Perineal lacerations are often caused by
Unprotected childbirth
What muscles are involved in a first degree perineal laceration?
None
T/F: A second degree perineal laceration does not involve urogenital structures
F
What muscle is cut in a third degree perineal laceration?
External anal sphincter
Primary function of external genitalia
Copulation and parturition
T/F: During the sixth week of gestation, genitalia can be differentiated
F
At what age of gestation are sex indicators present?
Seventh week AOG
The phallus is formed from what embryonic structure
Genital tubercle
In males, the urethral plate is formed from what embryonic structure
Epithelial lining of groove from endoderm
At what age of gestation is the penile urethra formed?
3rd month AOG
When is the definitive external urethral meatus formed?
4th month AOG
What structure moves caudally to form the scrotal swellings?
Genital swellings
What embryonic structure becomes the clitoris?
Genital tubercle
In females, the urethral folds form the _______
Labia minora
The labia majora are formed when the _______ enlarge greatly
Genital swellings
The area between the hymen and the labia majora
Vestibule
Male copulatory organ and outlet for urine and semen
Penis
Location of the root of the penis
Superficial perineal pouch
What structure attaches to the pubis?
Crura
What muscles compose the root of the penis?
Ischiocavernosus
Bulbospongiosus
Swollen end of the corpus spongiosum
Glans
Skin that covers the glans penis
Prepuce
Fold on ventral surface of the penis from urethral meatus to corona
Frenulum
Enumerate the cavernous bodies
- Corpora cavernosa
2. Corpora spongiosa
Ends distally to form the glans
Corpus spongiosum
Structure that encloses each corpus
Tunica albuginea
Encloses all three corpora
Buck’s fascia
Anchors erectile bodies of penis to the pubic symphysis
Suspensory ligament of the penis
Fibromuscular sac for the testis and associated structures
Scrotum
Causes the wrinkling of the scrotum with age
Dartos muscle
Demarcates the midline of the scrotum
Scrotal raphe
Function of the scrotum
Maintains a constant temperature ideal for sperm development and maturation – scrotal sac contracts when cold, relaxes when warm/hot
Function of testes
Sperm production
Hormone secretion
Cells that produce testosterone
Leydig cells
Remains of the peritoneum that covers the testes
Tunica vaginalis
In the 28th week AOG, the testes are located ________
In the inguinal canal, descending to the scrotum
Structure wherein sperm mature
Epididymis
Sensory and erectile tissue for sexual arousal and intercourse in females
Vulva / pudenda
Structure anterior to the pubic symphysis, pubic tubercles, and superior pubic rami in females
Mons pubis
Prominent folds of skin located on the sides of the pudendal cleft
Labia majora
Continuation of the Scarpa’s fascia in the perineum
Colles’ fascia
Structure that immediately surrounds the vestibule
Labia minora
Erectile organ located at the anterior junction of the left and right labia minora
Clitoris
Structure that immediately surrounds the vaginal orifice
Hymen
Structure that secretes mucus into the vestibule during sexual arousal
Bartholin’s gland
Location of Bartholin’s gland
Superficial perineal pouch
Paired masses of elongated erectile tissue found along the sides of the vaginal orifice
Bulbs of the vestibule
Difference between a penis and clitoris (structurally)
Clitoris does not have corpus spongiosum
The dorsal artery to the penis/clitoris is a branch of the _________
Internal pudendal artery
T/F: The main artery of the vulva is called the external pudendal artery
T
Collects blood from the venous plexus, draining the cavernous spaces
Deep dorsal vein of the penis
Lymphatic drainage from the glans and distal spongy urethra proceeds to what lymph nodes?
Deep inguinal and external iliac
Lymphatic drainage of the glans of the clitoris and anterior labia majora
Deep inguinal nodes
T/F: Sympathetic stimulation produces increased vaginal secretion, erection of clitoris, and engorgement of bulbs of the vestibule
F. Parasympathetic stimulation is what causes these responses
Provides sensory and sympathetic innervation to the glans and skin of the penis
Dorsal nerve of the penis
Nerve that supplies the anterior aspect of the vulva
Anterior labial nerve
Boundaries of the deep perineal space
Inferior - perineal membrane
Superior - inferior fascia of pelvic diaphragm
Lateral - obturator fascia
Males: Cowper’s gland :: Females: ________
Bartholin’s gland
Boundaries of ischiorectal fossa
Anterior - base of urogenital diaphragm and fascia
Posterior - gluteus maximus, sacrotuberous ligament
Lateral - ischium, obturator internus
Medial - external anal sphincter
Superomedial - levator ani
Contents of ischiorectal fossa
Fat
Inferior rectal vessels
Inferior rectal nerves
Parts of external anal sphincter
- Subcutaneous - circular part
- Superficial - elliptical part (central tendon to tip of coccyx)
- Deep - circular, overlaps internal anal sphincter
Muscles affected in 2nd degree perineal laceration
Posterior portion of superficial transverse perineal, bulbocavernosus
Muscles affectied in 3rd degree perineal laceration
Muscles cut in 2nd degree laceration
External anal sphincter
Muscles affected in 2nd degree perineal laceration
Muscles cut in 2nd and 3rd degree laceration
Anterior wall of rectum (lumen of rectum exposed)
T/F: urethral folds in females fuse to form the clitoris
F, they do not fuse, forming the labia minora
opening of urogenital groove to surface in females
vestibule
root of the penis is composed of:
Crura - attached to pubis
Bulb of the urethra/penis
Ischiocavernosus, bulbocavernosus
Part of the penis overhanging the neck of the glans
corona
What structure lies between the tunica albuginea and Buck’s fascia
Internal pudendal vessels
What structure lies between the loose CT layers and Buck’s fascia
superficial dorsal vein of the penis
Elongation of tunica dartos that divides the scrotum into 2 compartments
scrotal septum
midline of the scrotum
scrotal raphe
the scrotal raphe is continuous with:
penile raphe in the penis
perineal raphe in the perineum
Composed of connective tissue continuous with subcutaneous tissue of abdominal wall, and Colle’s fascia
Dartos fascia
which testis is usually suspended more inferiorly
left
the testes enter the scrotum at around:
32nd week of gestation
Presence of excess fluid in a persistent processus vaginalis
Hydrocoele
Dilated and tortous veins in the pampiniform plexus may result in
Varicocoele
The termination of the round ligament of the uterus is at the
atnerior portion of labia majora
Paraurethral glands open where?
on each side of the urethral orifice
Lesser vestibular glands open where?
between urethral and vaginal orifices
function of lesser vestibular glands
mucous secretion
