Extra: gross anatomy of the perineum and external genitalia

Question 1

Define anal columns

Answer 1

Contain terminal braches of superior rectal vessels, they terminate at the anal valves

Question 2

Define anal valves.

Answer 2

Folds of mucosa that form the pectinate line

Question 3

Define anal sinuses.

Answer 3

Located just above the valves and produce mucous to aid in defecation.

Question 4

Define perineal body

Answer 4

central tendon of the perineum attachment for many muscles that support the pelvic viscera

Question 5

What are the boundaries of the urogenital triangle?

Answer 5

It is located below levator ani and anterior to anal triangle. Boundaries: pubic symphysis, ischiopubic ramus and a line between ischial tuberosities.

Question 6

What are the contents of the urogenital triangle?

Answer 6

perineal membrane, erectile tissues, muscles, opening for urethra and vagina and perineal body.

Question 7

What structure divides the perineum into two pouches?

Answer 7

The perineal membrane.

Question 8

The deep perineal pouch borders.

Answer 8

The deep perineal pouch is located above the perineal membrane and below levator ani

Question 9

The superficial perineal pouch borders.

Answer 9

The superficial perineal pouch is below the perineal membrane

Question 10

What is the function of the paired bulbourethral glands?

Answer 10

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.

Question 11

What is the main mechanism to control the urethra?

Answer 11

The urethral sphincter

Question 12

What are the contents of the superficial perineal pouch?

Answer 12

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.

Question 13

Function of the greater vestibular glands.

Answer 13

Lubrication.

Question 14

Describe the erectile tissue in the superficial perineal pouch.

Answer 14

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

Question 15

What is the posterior edge of the perineal membrane covered by?

Answer 15

the superficial transverse perineal muscle

Question 16

Function of the ischiocavernosus m

Answer 16

Aids in maintaining erection in both males and females

Question 17

Function of the bulbospongiosus m

Answer 17

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’

Question 18

Function of the superficial transverse perineal muscle

Answer 18

supports the pelvic viscera and in males contracts during erection to support the penis.

Question 19

What is the superficial perineal fascia continuous with?

Answer 19

dartos fascia of scrotum, superficial penile fascia or labia majora and mons pubis, and membranous layer of superficial fascia of abdominal wall

Question 20

Attachments of the superficial perineal fascia.

Answer 20

Attaches to the posterior edge of the perineal membrane and lateral borders of the urogenital triangle.

Question 21

What is the deep perineal fascia continuous with?

Answer 21

closely invests superficial muscles of the perineum, and is continuous with deep penile fascia

Question 22

Function of the perineum body

Answer 22

helps support the pelvic viscera (along with pelvic diaphragm)

Question 23

Muscles that attach to the perineum body

Answer 23

Several muscles attach to the central

tendon; bulbospongiosus, superficial & deep transverse perineal m, external anal sphincter and part of levator ani.

Question 24

Anatomy of the penis

Answer 24

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)

Question 25

Lymphatic drainage of the male genitalia.

Answer 25

Lymph from skin to superficial inguinal lymph nodes, testis to – lumbar and preaortic nodes, urethra and cavernous bodies to internal iliac and deep inguinal nodes.

Question 26

Anatomy of the female external genitalia

Answer 26

Mons pubis, Labia majora (located on either side of the pudendal cleft). The vestibule and labia minora are located within the pudendal cleft. The labia major unite anteriorly to form the anterior commissure and posteriorly to form the posterior commissure.
The labia minora unite anteriorly to form the prepuce and frenulum of the clitoris and posteriorly to form the frenulum of the labia.

Question 27

Anatomy of the vestibule of the vagina

Answer 27

The vestibule of the vagina is located between the labia minor, it contains the external urethral orifice, orifice of vagina and openings of greater vestibular (Bartholin’s) glands

Question 28

Function of the greater vestibular glands

Answer 28

secrete mucous during sexual arousal

Question 29

Hymen of the vagina

Answer 29

The hymen is a thin mucous membrane that partly (or fully) occludes the vaginal orifice, it has no known physiological function.

Question 30

Anatomy of the clitoris

Answer 30

Clitoris – (body and glans, crura and bulb of vestibule - erectile tissue)