Surface anatomy of the perineum pdf - Perineum

Surface Anatomy

329

penile
urethra

glans

scrotum

anus

1
2

FIGURE 8.23

Types of hypospadias: (

(chordee) of the penis also is present.

) perineal. Ventral flexion

) penoscrotal, and (

) glandular, (

2) coronal,

(3) penile, (4

extrophy of bladder

glans

FIGURE 8.24

Types of epispadias.

natomy

aphic

adiog

The radiographic anatomy of the bones forming the

in Figures 8.25 and 8.26.

and 7.43. A cystourethrogram of the male urethra is shown

boundaries of the perineum is shown in Figures 7.39, 7.41,

natomy

face

The perineum when seen from below with the thighs

the anterior triangle, which

anal triangle;

anus, is called the

(see Fig. 8.2). The posterior triangle, which contains the

by joining the ischial tuberosities with an imaginary line

It is customary to divide the perineum into two triangles

weight of the body.

the lower border of the gluteus maximus and supports the

ting position, the ischial tuberosity emerges from beneath

tuberosity is covered by the gluteus maximus. In the sit

of the buttock (see Fig. 8.3). In the standing position, the

The ischial tuberosity can be palpated in the lower part

Ischial Tuberosity

the anus (see Fig. 8.3).

the cleft between the buttocks about 1 in. (2.5 cm) behind

The inferior surface and tip of the coccyx can be palpated in

midline at the lower extremity of the anterior abdominal wall.

and 8.28). It is felt as a solid structure beneath the skin in the

midline between the bodies of the pubic bones (Figs. 8.3, 8.27,

The symphysis pubis is the cartilaginous joint that lies in the

ischial tuberosities.

and laterally by the

coccyx,

posteriorly by the tip of

symphysis pubis,

anteriorly by the

abducted (see Fig. 8.2) is diamond shaped and is bounded

the

Symphysis Pubis

Coccyx

contains the urogenital orifices, is called the

scrotum.

The male urogenital triangle contains the penis and the

Male Urogenital Triangle

(Fig. 8.29).

Around the anal margin are coarse hairs

anal sphincter.

external

brown and is puckered by the contraction of the

in the midline. In the living, the anal margin is reddish

The anus is the lower opening of the anal canal and lies

Anal Triangle

triangle.

urogenital

Anus

330

CHAPTER 8

The Perineum

FIGURE 8.25

Cystourethrogram after intravenous injection of contrast medium (28-year-old man).

hip joint

head of femur

obturator
foramen

skin fold

ramus of ischium

membranous part of urethra

prostatic part
of urethra

bulbous part

of urethra

ischial
tuberosity

obturator foramen

lesser trochanter

inferior ramus
of pubis

body of penis

greater trochanter

head of femur

hip joint

anterior inferior

iliac spine

gas in bowel

cassette

scrotum

penile part of urethra

b lb

urinary bladder filled with
radiopaque material

body of pubis

FIGURE 8.26

The main features seen in the cystourethrogram shown in Figure 8.25.

Surface Anatomy

331

tuber cle

of iliac crest

anterior superior

iliac spine

umbilicus

male

distribution

of pubic hair

iliac

crest

greater trochanter

of femur

pubic

symphysis

pubis

scrotum

external

urethral orifice

glans penis

body

of penis

FIGURE 8.27

Anterior view of the pelvis of a 27-year-old man.

mons pubis showing

female distribution

of pubic hair

anterior superior

iliac spine

site of inguinal

ligament

pubic tubercle

umbilicus

iliac crest

greater trochanter

of femur

symphysis pubis

FIGURE 8.28

Anterior view of the pelvis of a 29-year-old woman.

332

CHAPTER 8

The Perineum

mons pubis

labium majus

vaginal orifice

anus

pubic hair

labium minus

fourchette

site of

ischial tuberosity

labium majus

labium minus

vaginal wall

union of labia majora

prepuce

of clitoris

external

urethral

meatus

fourchette

anus

FIGURE 8.29

The perineum in a 25-year-old woman, inferior view.

Extending from the

external urethral meatus.

glans is the

penis (see Figs. 8.13, 8.16, and 8.27). At the summit of the

forms the extremity of the body of the

glans penis

The

(see Fig. 8.13).

in the midline

superficial dorsal vein

usually possesses a

the dorsal surface (anterior surface of the flaccid organ)

which is suspended from the symphysis pubis. Note that

is the free portion of the penis,

body of the penis

The

the scrotum.

deep palpation in the midline of the perineum, posterior to

The bulb can be felt on

left crura of the penis.

right

bulb of the penis

masses of erectile tissue called the

consists of three

root of the penis

8.13, 8.16, and 8.27). The

The penis consists of a root, a body, and a glans (see Figs.

With labia separated.

With labia together.

Penis

and the

and

Surface Anatomy

The bilateral origin of the scrotum is indicated by the

of the scrotum is rugose and is covered with sparse hairs.

8.27) containing the testes and the epididymides. The skin

The scrotum is a sac of skin and fascia (see Figs. 8.12 and

extent, and it should be possible to retract it over the glans.

neck of the penis. The prepuce covers the glans for a variable

is formed by a fold of skin attached to the

foreskin

puce

pre

(see Fig. 8.16). The

corona

base of the glans is called the

The edge of the

frenulum.

glans to the prepuce called the

lower margin of the external meatus is a fold connecting the

333

Scrotum

presence of a dark line in the midline, called the

(see Fig. 8.29).

prepuce

is partly hidden by the

glans of the clitoris

Fig. 8.19). The

This is situated at the apex of the vestibule anteriorly (see

Clitoris

minus (see Fig. 8.19).

between the hymen and the posterior part of the labium

Small orifices, one on each side, are found in the groove

Vestibular Glands

tags of the hymen remain (see Fig. 8.19).

teriorly or posterolaterally, and after childbirth only a few

Fig. 8.19). At the first coitus, the hymen tears, usually pos

which is perforated at its center (see

hymen,

fold called the

The vaginal orifice is protected in virgins by a thin mucosal

Vaginal Orifice

fourchette at its base (see Figs. 8.19 and 8.29).

by the labia minora, with the clitoris at its apex and the

The vestibule is a smooth triangular area bounded laterally

Vestibule

(see Figs. 8.19

frenulum

and a posterior

prepuce

Anteriorly, they split to enclose the clitoris, forming an

fourchette.

terior ends are united to form a sharp fold, the

that lie between the labia majora (see Fig. 8.19). Their pos

The labia minora are two smaller, hairless folds of soft skin

Labia Minora

riorly in the midline (see Figs. 8.19 and 8.29).

extending posteriorly from the mons pubis to unite poste

The labia majora are prominent, hair-bearing folds of skin

Labia Majora

umbilicus.

rior margin, whereas in the male it extends upward to the

The pubic hair in the female has an abrupt horizontal supe

skin found anterior to the pubis (see Figs. 8.19 and 8.28).

The mons pubis is the rounded, hair-bearing elevation of

(see Figs. 8.19, 8.28, and 8.29).

“Vulva” is the term applied to the female external genitalia

Vulva

Female Urogenital Triangle

to enter the spermatic cord at the upper end of the scrotum.

emerges from the tail and ascends medial to the epididymis

vas deferens

inferiorly (see Fig. 4.21). The cordlike

and a pointed

body,

head,

having an expanded upper end or

of the testis. The epididymis is a long, narrow, firm structure

Each epididymis can be palpated on the posterolateral surface

ous tissue or skin.

nalis (see Fig. 4.21) and are not tethered to the subcutane

have a firm consistency. They lie free within the tunica vagi

The testes should be palpated. They are oval shaped and

Testes

along the line of fusion.

raphe,

scrotal

-
-

Epididymides

tail

Mons Pubis

and 8.29).

Orifices of the Ducts of the Greater

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