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Inguinal Region & Secrotum
Abdomen, Pelvis & Perineum Unit
Lecture 2
‫ حيدر جليل األعسم‬.‫د‬
Inguinal Canal
It is an oblique passage through
the lower part of the anterior
abdominal wall. It is about 4 cm
long in adult and extends from
the deep inguinal ring, downward
and medially to the superficial
inguinal ring. It lies parallel to and
immediately above the inguinal
ligament.
Inguinal Canal - Rings
The superficial inguinal ring:
It is a triangular-shaped opening in the
aponeurosis of external oblique muscle
and lies immediately above and medial to
pubic tubercle.
Margins of the ring, sometimes called
crura (medial & lateral), give attachment
to external spermatic fascia. The crura are
held by intercrural fibres at the apex of
the ring.
The deep inguinal ring:
It is an oval opening in fascia transversalis,
lies about 0.5 inch (1.3 cm) above inguinal
ligament midway between anterior
superior iliac spine and symphysis pubis
(Mid-inguinal Point). Medial to it, there
are inferior epigastric vessels.
Margins of the ring give attachment to
internal spermatic fascia (or internal
covering of round ligament of uterus).
Walls of Inguinal Canal
Anterior wall:
External oblique aponeurosis,
reinforced laterally by the origin of
internal oblique from the inguinal
ligament. It contain superficial
Inguinal ring medially.
Posterior wall:
Conjoint tendon medially, fascia
transversalis laterally. It contains
deep inguinal ring laterally.
Roof or superior wall:
Arching lowest fibers of internal
oblique & transversus abdominis
Floor or inferior wall:
Upturned lower edge of inguinal
ligament and lacunar ligament
medially.
Function of inguinal canal
In males, it allows structures of spermatic cord to
pass to and from the testis to the abdomen.
In females it allows round ligament of the uterus to
pass from uterus to labium majus.
Contents of inguinal canal
1- Genital branch of the genitofemoral nerve.
2- ilio-inguinal nerve passes through part of the canal, exiting
through the superficial inguinal ring
3- Spermatic cord in men and the round ligament of the
uterus in women.
Spermatic Cord
It is a collection of structures that pass through the inguinal canal to and
from the testis. It begins at the deep inguinal ring lateral to the inferior
epigastric artery and ends at the testis.
Structures of the Spermatic Cord:
1- Vas deferens: is thick-walled muscular duct
transports sperms from epididymis to urethra.
2- Testicular artery: is a branch of abdominal aorta
at level of L2 & supplies testis & epididymis
3- Testicular veins (pampiniform plexus): is an
extensive venous plexus (pampiniform plexus) that
leaves posterior border of testis and ascends
upward & becomes reduced in size to form
testicular vein at level of deep inguinal ring which
drains into left renal vein on left side and into
inferior vena cava on right side.
4- Testicular lymph vessels: drains into lumbar
(para-aortic) lymph nodes.
5- Autonomic nerves:
6- Remains of the processus vaginalis:
7- Genital branch of genitofemoral nerve: which
supplies the cremaster muscle
Coverings of the Spermatic Cord
They are three layers of fascia derived from the layers of the anterior
abdominal wall. Each covering is acquired as the processus vaginalis
descends into the scrotum through the layers of the abdominal wall.
1- External spermatic fascia derived from external oblique aponeurosis
and attached to the margins of
the superficial inguinal ring
2- Cremasteric fascia derived
from the internal oblique muscle
3- Internal spermatic fascia
derived from fascia transversalis
and attached to the margins of
the deep inguinal ring
Scrotum
Scrotum is an out-pouching of lower part of anterior abdominal wall. It
contains testes, epididymides, & lower ends of spermatic cords.
The wall of the scrotum has the following layers:
1- Skin: is thin, wrinkled & pigmented and forms a single pouch.
2- Superficial fascia: is continuous with fatty and membranous layers of
anterior abdominal wall; the fat is replaced by dartos muscle. This is
innervated by sympathetic nerve fibers. It is attached to the perineal
body and the posterior edge of the perineal membrane. At the sides it is
attached to the ischiopubic rami. Both layers of superficial fascia
contribute to median partition that crosses scrotum & separates testes.
3- Spermatic fasciae: lie beneath superficial fascia and are derived from
the three layers of the anterior abdominal wall.
4- Tunica vaginalis: lies within spermatic fasciae and covers anterior,
medial & lateral surfaces of each testis. It is the lower expanded part of
processus vaginalis; normally, just before birth, it becomes
disconnected from upper part of processus and peritoneal cavity.
Lymph Drainage of the Scrotum
Lymph from the skin and fascia, including the tunica
vaginalis, drains into superficial inguinal lymph nodes
Testis
The testis is a firm, mobile organ lying within the scrotum. The left testis
usually lies at a lower level than the right. Each testis is surrounded by a
tough fibrous capsule, Tunica Albuginea. Extending from inner surface
of the capsule is a series of fibrous septa that divide the interior of testis
into lobules. Lying within each lobule are 1-3 coiled seminiferous
tubules that open into a network of channels called the rete testis.
Small efferent ductules connect rete testis to upper end of Epididymis.
Epididymis
The epididymis is a firm structure lying posterior to the testis, with the
vas deferens lying on its medial side. It has an expanded upper head, a
body, and a pointed tail inferiorly. Laterally, a distinct groove lies
between the testis and epididymis, which is lined by inner visceral layer
of the tunica vaginalis and is called sinus of the epididymis.
Blood Supply of Testis and Epididymis
Arterial supply of testis and epididymis is by testicular artery (a branch
of abdominal aorta).
Testicular veins emerge from testis & epididymis as a venous network
(pampiniform plexus) which
becomes reduced to a single
vein (testicular vein) as it
ascends through the inguinal
canal. The right testicular vein
drains into the inferior vena
cava, and the left vein joins
the left renal vein.
Lymph Drainage of Testis and Epididymis
Lymph vessels ascend in the spermatic cord and end in the lymph nodes
on the side of the aorta (lumbar or para-aortic) nodes.
Lymph Drainage of Testis and Epididymis
Lymph vessels ascend in the spermatic cord and end in the lymph nodes
on the side of the aorta (lumbar or para-aortic) nodes.
Labia Majora
Labia majora are prominent, hair-bearing folds of skin formed by the
enlargement of genital swellings in the fetus. (In the male, genital
swellings fuse in the midline to form the scrotum.) Within labia are a
large amount of adipose tissue and terminal strands of round ligaments
of uterus.
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