Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Human Anatomy ppt lectures Topic 49 Inguinal Canal Notes. - anatomy ppt free download human anatomy ppt lectures, medicine notes ppt, anatomy handwritten notes pdf, mbbs 1st year anatomy notes pdf download, best anatomy notes pdf, human anatomy notes pdf, anatomy easy notes pdf, anatomy notes online, anatomy short notes, Anatomy ppt, Powerpoint Presentations and lecture notes.
Inguinal canal
2.2.6 Inguinal area
Surface anatomy
Inguinal Canal
? It is an oblique intermuscular passage through the lower
part of the anterior abdominal wall
? Present in both sexes
? It allows structures to pass to and from the testis to the
abdomen in males
? In females it permits the passage of the round ligament
of the uterus from the uterus to the labium majus
? Transmits ilioinguinal nerve in both sexes
Inguinal Canal
? It is about 1 ? inches or 4cm long in the adults
? Extends from the deep inguinal ring downward
and medially to the superficial inguinal ring
? Lies parallel to and immediately above the
inguinal ligament
? In the newborn child, the deep ring lies almost
directly posterior to the superficial ring
Deep Inguinal Ring
? Is an oval opening in the fascia
transversalis
? Lies about ? inch (1.3cm) above the
inguinal ligament midway between the
anterosuperior iliac spine and the
symphysis pubis
? Margins of the ring give attachment to the
internal spermatic fascia
Superficial Inguinal Ring
? Is triangular in shape
? Lies in the aponeurosis of the external
oblique muscle
? Lies immediately above and medial to the
pubic tubercle
? Its margins give attachment to the external
spermatic fascia
Anterior Wal of Inguinal Canal
? Is formed along its entire length by
aponeurosis of the external oblique muscle
? It is reinforced in its lateral third by the
origin of the internal oblique from the
inguinal ligament
? This wall is strongest where it lies opposite
the weakest part of posterior wall, that is
deep inguinal ring
Posterior Wal of Inguinal Canal
? Is formed along its entire length by the fascia
transversalis
? It is reinforced in its medial third by conjoint
tendon, the common tendon of insertion of
internal oblique and transversus, attached to the
pubic crest and pectineal line
? This wall is strongest where it lies opposite the
weakest part of the anterior wall, that is
superficial inguinal ring
Inferior Wal of Inguinal Canal
? Is formed by the rolled-under inferior edge
of the aponeurosis of the external oblique
muscle called inguinal ligament and at its
medial end, the lacunar ligament
Superior Wal of Inguinal
Canal
? Is formed by the arching lowest fibers of
the internal oblique and transversus
abdominis muscles
Functions of Inguinal Canal
? It allows structures of spermatic cord to
pass to and from the testis to the abdomen
in male
? Permits the passage of round ligament of
uterus from the uterus to the labium majus
in female
Mechanics of Inguinal Canal
? Flap valve mechanish- oblique canal,
deep & sup. Ing ring do not lie opposite to
each other- increased intra abdo pressure
? ant & post wall are approximated like a
flap.
? Guarding of the inguinal rings- deep ing
ring guarded ANTERIORLY by IOM, Sup.
Ing ring guarded posteriorly ? conjoint
tendon & reflected part of ing lig.
Mechanics of Inguinal Canal
? Shutter Mechanism- IOM surrounds the
canal in front, above & behind like a
flexible mobile arch. When it contracts roof
is pulled & approximated on the floor like a
shutter
? slit- valve mechanism- contraction of EOM
approximates the two crura of sup ing.
Ring like a slit valve , the intercrural fibers
also help.
Mechanics of Inguinal Canal
? Ball valve Mechanism-
contraction of cremaster muscle pulls the
testis up & sup. Ing. Ring is plugged by
spermat. Cord.
Spermatic Cord
? It is a collection of structures that pass
through the inguinal canal to and from the
testis
? It is covered with three concentric layers of
fascia derived from the layers of anterior
abdominal wall
? It begins at the deep inguinal ring lateral to
the inferior epigastric artery and ends at
the testis
2.2.6 Inguinal area
Spermatic cord
? 3 Fascia layers
3 Nerves
Genito-femoral nerve
l External spermatic
fascia
Ilio-inguinal nerve
Sympathetic
l Cremasteric fascia
autonomic plexus
l Internal speratic fascia 3 Other structures
? 3 Arteries
Lymphatic vessels
Ductus deferens
l Testicular artery
Pampiniform venous
l Cremasteric artery
plexus
l Artery to ductus
deferens
2.2.6 Inguinal area
Spermatic cord
Vas Deferens
? It is a cord like structure
? Can be palpated between finger and
thumb in the upper part of the scrotum
? It is a thick walled muscular duct that
transport spermatozoa from the epididymis
to the urethra
Testicular Artery
? It is a branch of abdominal aorta
? It is long and slender
? Descends on the posterior abdominal wall
? It traverses the inguinal canal and supplies
the testis and the epididymis
Testicular Veins
? These are the extensive venous plexus, the
pampiniform plexus
? Leaves the posterior border of the testis
? As the plexus ascends, it becomes reduced in
size so that at about the level of deep inguinal
ring, a single testicular vein is formed
? Drains into left renal vein on left side and inferior
vena cava on right side
Covering of the Spermatic Cord
? The covering of the spermatic cord are
three concentric 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
Covering of the Spermatic Cord
? External Spermatic fascia: Is derived from the
external oblique aponeurosis and attached to the
margins of the superficial inguinal ring
? Cremasteric Fascia: Is derived from the internal
oblique muscle
? Internal Spermatic Fascia: Is derived from the
fascia transversalis and attached to the margins
of deep inguinal ring
Inguinal Hernia
? A hernia is the protrusion of part of the
abdominal contents beyond the normal
confines of the abdominal wall
? Hernial coverings are formed from the
layers of the abdominal wall through which
the hernial sac passes
Inguinal canal
Inguinal
? An Inguinal hernia is a
protrusion of contents of
hernia
abdominal-cavity through
the Inguinal canal.
? Bulges through a weak
area in the lower abdominal
muscles.
? An inguinal hernia appears
as a bulge on one or both
sides of the groin. An
inguinal hernia can occur
any time from infancy to
adulthood.
? Inguinal hernias tend to
become larger with time.
? More common in males
? In the case of the female, the opening of the superficial
inguinal ring is smaller than that of the male.
? As a result, the possibility for hernias through the
inguinal canal in males is much greater because they
have a larger opening and therefore a much weaker wall
for the intestines to protrude through.
Parts of hernia
? Consists of four parts: the sac, contents of
the sac, covering of the sac and neck.
? Hernial coverings are formed from the layers
of the abdominal wall through which the
hernial sac passes.
? In Amyand's hernia, the content of the hernial
sac is the vermiform appendix.
? In Littre's hernia, the content of the hernial
sac contains a Meckel's Diverticulum.
INGUINAL (HESSELBACH'S)
TRIANGLE
? INGUINAL (HESSELBACH'S) TRIANGLE is an area of
the anterior abdominal wall bounded by
? Inferior epigastric vessels,
? Inguinal ligament and
? Lateral border of the rectus abdominis.
? Direct inguinal hernias leave the abdomen through this
triangle.
? Boundaries
? Medial border: Lateral margin of the rectus
sheath, also called linea semilunaris
? Superolateral border: Inferior epigastric
vessels
? Inferior border: Inguinal ligament, sometimes
referred to as Poupart's ligament
? This can be remembered by the mnemonic
RIP (as direct inguinal hernias rip directly
through the abdominal wall).
2.2.6 Inguinal area
Hesselbach's triangle
Two types of inguinal hernia
l
DIRECT AND
l
INDIRECT,
? which are defined by their relationship to the inferior
epigastric vessels.
? Direct inguinal hernias occur medial to the inferior epigastric
vessels when abdominal contents herniate through a weak spot
in the fascia of the posterior wall of the inguinal canal, which is
formed by the transversalis fascia.
? Indirect inguinal hernias occur when abdominal contents protrude
through the deep inguinal ring, lateral to the inferior epigastric
vessels; this may be caused by failure of embryonic closure of
the processus vaginalis.
? Indirect inguinal hernia.
l Indirect inguinal hernias are congenital hernias.
? More common in males than females
? Indirect hernias are the most common type of
inguinal hernia.
? More common on right side.
? The neck of the hernial sac lies at the deep
inguinal ring
? Premature infants are especially at risk for indirect
inguinal hernias because there is less time
for processus vaginalis to obliterate.
? In a male fetus, the spermatic cord and both testicles--
starting from an intra-abdominal location--normally
descend through the inguinal canal into the scrotum,
the sac that holds the testicles
? Sometimes the entrance of the inguinal canal at the
inguinal ring does not close as it should just after birth,
leaving a weakness in the abdominal wall.
? Fat or part of the small intestine slides through the
weakness into the inguinal canal, causing a hernia.
? In females, an indirect inguinal hernia is caused by the
female organs or the small intestine sliding into the
groin through a weakness in the abdominal wall.
Direct inguinal hernias
?
Caused by connective tissue degeneration of the
abdominal muscles, which causes weakening of
the muscles.
?
Common in old men with weak abdominal
muscles and rare in women
?
The neck of the hernial sac is wide
? The hernia involves fat or the small intestine
sliding through the weak muscles into the groin.
? A direct hernia develops gradually because of
continuous stress on the muscles.
? One or more of the following factors can cause
pressure on the abdominal muscles and may
worsen the hernia:
l sudden twists, pulls, or muscle strains
l lifting heavy objects
l straining on the toilet because of constipation
l weight gain
l chronic coughing
Indirect Inguinal Hernia
? It is the most common form of hernia
? Is believed to be congenital in origin
? The hernial sac is remains of processus
vaginalis
? Enters the inguinal canal through the deep
inguinal ring lateral to the inferior epigastric
vessels
? It may extend part of the way along the canal or
as far as the superficial inguinal ring
Indirect Inguinal Hernia
? If the processus vaginalis has undergone no
obliteration, the hernia is complete and extends
through the superficial inguinal ring down into the
scrotum or labium majus
? Under these circumstances the neck of the
hernial sac lies at the deep inguinal ring
? It is 20 times more common in young males than
females
? Is more common on the right side
Direct Inguinal Hernia
? It composes about 15% of all inguinal hernias
? Common in old men with weak abdominal
muscles and rare in women
? Hernial sac bulges forward through the posterior
wall of the inguinal canal medial to the inferior
epigastric artery
? The neck of the hernial sac is wide
This post was last modified on 05 April 2022