28. Male and Female Perineum Flashcards

1
Q

Viewed from below, the perineum is a diamond-shaped area located between the thighs — what are the lateral, posterior, and anterior boundaries of the perineum?

A

Lateral = ischiopubic rami and sacrotuberous ligament

Posterior = coccyx

Anterior = pubic symphysis

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2
Q

The perineum can be described as a 3D structure which has superior and inferior limits. The superior boundary, or _____ _____ separates the perineum from the pelvic cavity. The inferior boundary is the surface of the skin associated with the ______ _____ and anal canal

A

Pelvic diaphragm; external genitalia

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3
Q

The perineum can be divided into 2 triangles by drawing an imaginary horizontal line between the 2 _____ _______. In the midline, this line will pass through the ____ ______.

What are the 2 named triangles this line makes?

A

Ischial tuberosities; perineal body

Urogenital triangle; anal triangle

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4
Q

What are the boundaries of the urogenital triangle?

A

Pubic symphysis
Ischiopubic rami
Imaginary line drawn between ischial tuberosities

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5
Q

What are the boundaries of the anal triangle?

A

Coccyx
Sacrotuberous ligaments
Imaginary line drawn between ischial tuberosities

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6
Q

The _____ ______ are wedge-shaped spaces on either side of the anal canal

A

Ischiorectal fossae

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7
Q

What are the boundaries of the ischiorectal fossae including the lateral walls, superomedial walls, and bases?

A

Lateral wall = obturator internus and ischium

Superomedial wall = levator ani and anal canal

Base = skin of perineum

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8
Q

The ____ ___ is 4 cm long and continuous with the rectum. It is oriented in a posteroinferior direction, due in part fo the anterior pull of the _______ m. It terminates at the anus

A

Anal canal; puborectalis

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9
Q

2 sets of anal sphincters surround the anal canal. The _______ is a layer of circular smooth muscle found in the upper 2/3 of the anal canal; it is controlled by _______ fibers from ______ nerves

A

Internal anal sphincter; parasympathetic; pelvic splanchnic

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10
Q

The ________ is composed of circular skeletal muscle which surrounds the lower 2/3 of the anal canal. These muscle fibers are attached to the _____ ligament posteriorly, and the ________ anteriorly. It is consciously controlled by the ______ n., a branch of the ______ n.

A

External anal sphincter; anococcygeal; inferior rectal; pudendal

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11
Q

What anatomical distinction makes distension of the anal canal possible during defecation?

A

Made possible bc the ischiorectal fossae are filled with fat (in other words, there are no vital organs in close proximity to interfere with its distention)

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12
Q

On the lateral walls of the ischiorectal fossae are the ____ _____, located on the medial surface of the ____ ___ m.

A

Pudendal canals; obturator internus

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13
Q

Contained within the pudendal canals are the _____ n. and the _______ a. and v. Passing from the pudendal canal to the anal canal are the _______ artery, vein, and nerve which travel through the ischiorectal fossae

A

Pudendal; internal pudendal; inferior rectal

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14
Q

The urogenital triangle can be divided into _____ and _____ spaces

A

Deep; superficial perineal

[pouches or spaces]

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15
Q

The deep perineal pouch in the urogenital triangle include the _____ _____, a continuous sheet of muscle that spans the gap between the ischiopubic rami. The superior fascia and inferior fascia of the perineal membrane are fused along the anterior and posterior borders. The ____ _____ is attached to the midpoint of the posterior border

A

Urogenital diaphragm; perineal body

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16
Q

In women, the urogenital diaphragm is split into two halves by the vagina. Contained within this diaphragm are the following:

The first part of the urethra in ______, and the membranous urethra in _____.

Deep perineal muscles: in males, the external urethral sphincter surrounds the _________ urethra. It relaxes to allow urination to occur or when ejaculation occurs. The ___________ m. inserts in the perineal body in both males and females.

The _______ glands in males have ducts which empty into the ______ urethra; during sexual excitement they secrete a clear mucous which lubricates the urethra prior to ejaculation

A

Females; males

Membranous; deep transverse perineus

Bulbourethral; penile

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17
Q

The superficial perineal space is a potential space deep to the perineal skin that covers the external genitalia. In females, this space is split in 2 halves by the _____ of the vagina.

A

Vestibule

18
Q

What are the contents of the superficial perineal space in males?

A
Root of penis + right and left crura
Bulb of penis
Ischiocavernosus m.
Bulbospongiosus m.
Superficial transverse perineus m.
19
Q

In males, the _____ m. (bilateral) surround the free surface of each _____ of the root of the penis. They attach to the ischiopubic rami and insert into the _____ _____ which is comprised of erectile tissue

A

Ischiocavernosus; crus; corpora cavernosa

20
Q

How do the ischiocavernosus and bulbospongiosus mm. help to maintain an erection in males?

A

They compress the veins which drain the corpora cavernosa

21
Q

The _____ m. in males arises from the perineal body and raphe of the penis, then wraps around the bulb and posterior part of the _____ ______, which is also comprised of erectile tissue. It aids in compressing/emptying the urethra of urine or semen.

A

Bulbospongiosus; corpus spongiosum

22
Q

______ _____ fascia covers the muscles in the superficial perineal space

A

Deep perineal

23
Q

What muscle is located in the superficial perineal space, along the posterior border of the UG diaphragm?

A

Superficial transverse perineus m.

24
Q

The body, or shaft, of the penis consists of skin and three bodies of erectile tissue, including the _______ and bilateral _______. ____ fascia covers the 3 sets of erectile tissue

A

Corpus spongiosum; corpora cavernosa; Buck’s

25
Q

The superficial perineal space in females contains the vulva or external genitalia, which includes what major structures?

A
Labia majora
Labia minora
Mons pubis
Vestibule of vagina
Clitoris
Bartholin’s glands
Superficial transverse perineus m.
26
Q

The labia majora unite anteriorly to form the ______. The labia minora surround the vestibule of the vagina, which contains the external urethral orifice, vaginal orifice, openings of the _____ glands, and the ________ _____ glands. The urethra contains an external urethral sphincter which relaxes to allow urination to occur.

A

Mons pubis; paraurethral; greater vestibular

27
Q

The clitoris is the female homologue to the penis in males. What are the major parts of the clitoris?

A

Two crura
Two corpora cavernosa
One body
One glans clitoris

28
Q

Each crus of the clitoris is continuous with a ________, which is composed of erectile tissue. These 2 parts are surrounded by an _________ m., which contracts during sexual arousal to slow the return of venous blood from the corpus cavernosum

A

Corpus cavernosum; ischiocavernosus

29
Q

In females, the 2 corpora cavernosa unite to form the ______. The _______ is attached to the body and is axternally visible

A

Body of the clitoris; glans clitoris

30
Q

In addition to the vulva, the superficial perineal space in females includes several important strucures which are deep to the skin. These include:

The _____ of the vestibule, which are located deep to the skin of the labia minora and are comprised of erectile tissue. Each one is covered by a _______ m., which is attached to the perineal body. During sexual arousal this muscle compresses the bulbs of the vestibule to slow the return of venous blood.

_______ glands, which produce a clear mucous during sexual arousal which lubricates the vulva

_______ mm. which attach to the perineal body

A

Bulbs; bulbocavernosus

Greater vestibular (Bartholin’s)

Superficial transverse perineus

31
Q

Arterial supply to the perineum is provided by two major vessels:

The ______ a., which is a branch of the ______, enters the perineum via the lesser sciatic foramen and then enters the pudendal canal. It gives branches to the anal canal and ischiorectal fossa, deep perineal space, and superficial perineal space. Included in its important branches are the _____ arteries, which supply the erectile tissues and dorsal arteries of the penis and clitoris.

The ______a., a branch of the _______, sends deep and superficial branches to the scrotum and penis in the male, and the labia majora and clitoris in the female

A

Internal pudendal; internal iliac a.; helicine

External pudendal; femoral

32
Q

The _______ n. Sends branches to all perineal structures supplied with blood from the internal pudendal a.

A

Pudendal n. (S2-S4)

33
Q

What 4 modalities are included in the pudendal n. (S2-4) supplying the perineal region?

A

Preganglionic parasympathetics (GVE) — glands and smooth muscle

Somatic motor fibers (GSE) — skeletal m.

Somatic sensory fibers (GSA) — sensation in perineal skin, distal portion of anal canal, distal vaginal canal

Postganglionic sympathetic fibers (GVE) — glands and smooth muscle

34
Q

In addition to the pudendal n., what other n. supplies the perineal region with cutaneous branches?

A

Posterior femoral cutaneous n.

35
Q

The superficial perineal space, distal portions of the vagina, and anal canal (below the pectinate line) drain to the _______ nodes.

The deep perineal space, proximal portion of vagina, proximal portion of anal canal (above pectinate line) drain to _____ nodes

A

Superficial inguinal

Internal iliac

36
Q

_______ = surgical incision made in the area between the vagina and anus during the last stages of labor and delivery to expand the opening of the vagina to prevent a perineal tear during delivery

A

Episiotomy

37
Q

What are the 4 types of episiotomy, which one is the most common?

A

Mediolateral episiotomy

38
Q

What structures are cut during a typical episiotomy?

A

Posterior vaginal wall
Bulbocavernosus m.
Superficial transverse perineus m.
Skin and associated subcutaneous fascia

39
Q

To repair an episiotomy, the obstetrician places 3 layers of sutures in what order?

A
  1. Vaginal wall
  2. Muscle layer
  3. Subcutaneous fascia and skin
40
Q

What are the 4 types of episiotomy?

A

Medio-lateral (most common)
Midline
Lateral
J-shaped

41
Q

What autonomic plexus supplies the prostate, vesicle, utero-vaginal region, and rectum?

A

Inferior Hypogastric plexus

42
Q

What foramina do the internal pudendal vessels and pudendal n. pass through?

A

Greater and lesser sciatic foramina