Extra: gross anatomy of the perineum and external genitalia Flashcards
Define anal columns
Contain terminal braches of superior rectal vessels, they terminate at the anal valves
Define anal valves.
Folds of mucosa that form the pectinate line
Define anal sinuses.
Located just above the valves and produce mucous to aid in defecation.
Define perineal body
central tendon of the perineum attachment for many muscles that support the pelvic viscera
What are the boundaries of the urogenital triangle?
It is located below levator ani and anterior to anal triangle. Boundaries: pubic symphysis, ischiopubic ramus and a line between ischial tuberosities.
What are the contents of the urogenital triangle?
perineal membrane, erectile tissues, muscles, opening for urethra and vagina and perineal body.
What structure divides the perineum into two pouches?
The perineal membrane.
The deep perineal pouch borders.
The deep perineal pouch is located above the perineal membrane and below levator ani
The superficial perineal pouch borders.
The superficial perineal pouch is below the perineal membrane
What is the function of the paired bulbourethral glands?
The paired bulbourethral (Cowper’s) glands produce a small amount of fluid that neutralizes any acidic urine present in the urethra prior to ejaculation and to lubricate urethra for passage of sperm.
What is the main mechanism to control the urethra?
The urethral sphincter
What are the contents of the superficial perineal pouch?
the main components of the superficial pouch are the erectile tissues, the crus and the bulb, which are encased in muscle the ischiocavernosus and bulbospongiosus mm.
Females also have Greater Vestibular (Bartholin’s) glands with ducts opening near the external opening of the vagina; the superficial transverse perineal muscle is also located at the posterior edge of the superficial side of the perineal membrane.
Function of the greater vestibular glands.
Lubrication.
Describe the erectile tissue in the superficial perineal pouch.
Two corpora cavernosa have a free end and an attached end. The attached ends are joined to the pubic arches; they then travel together into the body of the penis or clitoris. Where the corpora cavernosa is joined to the pubic arches it is also called the crus (plural crura). The bulb is attached to superficial surface of perineal membrane. The bulb of penis - continues into body of penis as corpus spongiosum and contains the spongy urethra.
In the female the bulb of vestibule is a paired structure either side of the opening of the vagina, it then continues into the glans clitoris
What is the posterior edge of the perineal membrane covered by?
the superficial transverse perineal muscle
Function of the ischiocavernosus m
Aids in maintaining erection in both males and females
Function of the bulbospongiosus m
supports the pelvic floor and assists in erection; in males it aids in emptying urine and semen from the urethra, in females acts as a ‘vaginal sphincter’
Function of the superficial transverse perineal muscle
supports the pelvic viscera and in males contracts during erection to support the penis.
What is the superficial perineal fascia continuous with?
dartos fascia of scrotum, superficial penile fascia or labia majora and mons pubis, and membranous layer of superficial fascia of abdominal wall
Attachments of the superficial perineal fascia.
Attaches to the posterior edge of the perineal membrane and lateral borders of the urogenital triangle.
What is the deep perineal fascia continuous with?
closely invests superficial muscles of the perineum, and is continuous with deep penile fascia
Function of the perineum body
helps support the pelvic viscera (along with pelvic diaphragm)
Muscles that attach to the perineum body
Several muscles attach to the central
tendon; bulbospongiosus, superficial & deep transverse perineal m, external anal sphincter and part of levator ani.
Anatomy of the penis
Comprised of the root containing corpora cavernosa(crus) and corpus spongiosum, the body containing corpora cavernous and corpus spongiosum and the glans contains corpus spongiosum. The spongy urethra travels through the corpus spongiosum. At the junction to the body and glans penis a double layer of skin superficial fascia continue over the glans penis to form the prepuce (foreskin)
