The UG triangle Flashcards
how are the UG and Anal triangles divided?
• Divided by an imaginary line extending between the ischial tuberosities
what borders the UG triangle?
anterior: pubic bone
laterally: ischiopubic ramus
posterior: line between ischial tuberosities
what is contained within the UG triangle?
urogenital hiatus
how are the genitals placed in the UG triangle?
tilted triangle so that the genitals are oriented posteriorly
what borders the anal triangle
Anterior: line between the ischial tuberosities
Lateral: ST ligament
Posterior: coccyx
what is contained in the anal triangle?
rectal hiatus
what is the perineal membrane
• Through, thin sheet of fascia covering the UG triangle
what is anchored by the perineal membrane?
genetilia
how is the perineal membrane divided into?
2 spaces (deep and superficial perineal pouches
which pouch is found superior to the perineal membrane?
deep perineal pouch
which pouch is found inferior to the perineal membrane?
superficial perineal pouch
what is located in the superficial perineal pouch?
external genitalia
what forms the posterior border of the superficial perineal pouch?
superficial transverse perineal muscle
what is contained in the superifical perineal pouch in females?
greater vestibular gland
what muscle is contained within the deep transverse perineal pocuh?
deep transverse perineal Muscle
what male sphincters/glands are found in the deep perineal pouch?
external urethral sphincter
bulbourethral gland
what female sphincters/glands are found in the deep perineal pouch?
External urethral sphincter Urethrovaginal sphincter
what is the perineal body?
Small mass of fibrous tissue located at the midpoint of the line between the ischial tuberosities
where is the perineal body located?
between UG and Anal triangles
what is the function of the perineal body?
Point of attachment for anal and urethral sphincters and attachment point for deep/superficial transverse perineal muscles
what is the perineal body essential for?
Essential to the integrity to the entire pelvic floor
when doing epistotomy, what are we trying not to cut?
the perineal body
the perineal body is found posterior to what in females? male?
vestibule in females
bulb of penis in males
what is the main function of the transverse perineal muscle?
provides strength to the perineal body
what is the central component of the root of the penis?
bulb
what extends on either side of the penis from the root?
crura
where does the crura of the penis attach to
on the ischiopubic ramus
what are the columns of erectile tissues formed by crura?
2x copora cavernosus
1x corpus spongiosum
what column(s) forms the dorsal surface of the penis?
copora cavernous
where does copora cavernous extend from?
Forms from the right and left crus of the penis
where does corpus spongiosum extend from?
Forms the bulb of the penis
what is contained in corpus spongiosum?
spongey urether
where can corpus spongiosum be seen?
on the ventral side of the penis
what are the glans of the penis?
a corn shaped end of the penis (distal)
how can the dorsal side of the penis be identified?
when the penis is erect, it faces towards us, its the top portion
how can the ventral side of the penis be identified?
when the penis is erect, it faces away from us, its the lower portion
where does the deep penile A travel?
o Travel within the corpora cavernosa and corpus spongiosum to allow for the penile tissue to engorge with blood
what is drained by the dorsal penile vein?
o Drains blood from the penis
what happens to the dorsal penile vein to maintain erection?
o Engorgement of penile muscles impinges on the vein
what is the function of the skeletal muscles that cover the root of the penis?
o Assists in maintenance of erection and process of ejaculation
what are the muscles that cover the root of the penis?
Ischiocavernosus muscle
Bulbospongiosus muscle
what muscle covers the crura of the penis?
Ischiocavernosus muscle
what is the Ischiocavernosus muscle involved in?
- Helps maintain erection and pushes blood in the shaft and holds it there
- Involved in ejactulation due to pulsile type of contraction
what muscle covers the bulb of the penis?
Bulbospongiosus muscle
what is the foreskin attached to?
o Attached to the shaft of the penis via frenulum
what is cut during circumscion?
the frenulum to remove the foreskin
what is the equivalent in females to the scrotum in males?
labia majora
what is the erectile tissue in females?
clitoris
what forms the crura of the clitoris?
Formed corpora cavernos
what covers the crura of the clitoris?
Covered by ischiocavernosus muscles
how is the body of the clitoris formed?
Formed from the merging of the R/L crura
where is the bulb of the vestibule located?
Located between labia majora and minora
what is found on either side of the vestibule?
o Aggregates of erectile tissue on either side of the vestibule
what aggregates in the bulb of the vestibule?
blood
what muscle covers the corpus spongiosum in females?
bulbospongiosus muscle
what is the equivalent in females to the bulbourethral gland in males?
Greater vestibular glands
where is the Greater vestibular glands located?
superficial perineal pouch
what is the function of the Greater vestibular glands
Responsible for secreting mucus to lubricate the vagina via 2 small ducts
what branches arise from the internal pudendal V and A
rectal aa/vv
Perineal branches
where does the pudendal N come from
S2-S4
what branches arise from the pudendal N?
rectal nn
perineal branches
what gets innervated by the perineal branches of the pudendal N
genitals
what type of innervation is provided by the pudendal N?
sensory to the gentials and motor contraction to the muscles
what provides sympathetic innervation to the UG triangle?
o Lumbar and sacral splanchnic N
what provides parasympathetic innervation to the UG triangle?
o Pelvic splanchinic N S2-S4
what provides stimulation to the genitalia?
o Somatic sensory innervation via the pudendal N
what provides innervation during erection?
Parasympathetic innervation via the pelvic splanchnic N
what happens by the parasympatheic innervation to obtain erection?
relaxes the penile A, expands and compresses the penile veins to inhibit drainage
what gives innervation to maintain erection?
Pudendal N innervates bulbospongiosus and ischiocavernosus muscles to hold contraction and maintain erection
what trick can be used to maintain erection?
S2-3-4 keeps penis off the floor
how is the emission phase innervated?
via Sympathetic innervation of the lumbar and sacral splanchnic nerves
what happens during emission phase?
Sympathetic innervation to spermatic tubes to allow for contractions of ductus deferens, seminal vesicles, prostatic contraction, contraction of the internal urethral sphincter
what will prevent semen from entering the bladder?
bulbourethral gland when contracted
what gland in females is controled during the emission phase via sympathetic innervation of the lumbar and sacral splanchnic nerves?
the greater vestibular gland
what allows for ejaculation to occur?
motor impluses of rythmic contraction of the bulbospongiosus and ischiocavernosus muscle allowing to push semen through the penis
what gives sympathetic innervation to the uterus.vagina.clitoris?
o Lumbar and sacral splanchnic nerves through the inferior hypogastric plexus
what does the sympathetic innervation stimulate in females?
uterine contractions during labour
what provides parasympathetic innervation in females?
o Pelvic splanchnic nerves via inferior hypogastric plexus
what does the parasympathetic innervation stimulate in females?
relaxation of uterine muscle and vasodilation to allow engorgement of erectile tissues
