Inguinal canal and hernia

Question 1

What is the inguinal canal?

Answer 1

An oblique intermuscular passage in the lower anterior abdominal wall.

Question 2

Where is the inguinal canal located?

Answer 2

Just above the medial half of the inguinal ligament.

Question 3

What is the length of the inguinal canal?

Answer 3

About 4 cm (1.5 inches).

Question 4

In what direction does the inguinal canal run?

Answer 4

Downwards, forwards, and medially.

Question 5

What are the two openings of the inguinal canal?

Answer 5

Deep inguinal ring and superficial inguinal ring.

Question 6

What is the deep inguinal ring?

Answer 6

An oval opening in the fascia transversalis.

Question 7

Where is the deep inguinal ring located?

Answer 7

1.2 cm above the midinguinal point, lateral to the inferior epigastric artery.

Question 8

What is the superficial inguinal ring?

Answer 8

A triangular gap in the external oblique aponeurosis.

Question 9

What forms the base of the superficial inguinal ring?

Answer 9

The pubic crest.

Question 10

What forms the margins of the superficial inguinal ring?

Answer 10

Lateral and medial crura.

Question 11

What unites the crura of the superficial inguinal ring?

Answer 11

Intercrural fibers.

Question 12

What structures form the anterior wall of the inguinal canal?

Answer 12

Skin, superficial fascia, and external oblique aponeurosis.

Question 13

What additionally strengthens the lateral one-third of the anterior wall?

Answer 13

Fleshy fibers of the internal oblique muscle.

Question 14

What structures form the posterior wall of the inguinal canal?

Answer 14

Fascia transversalis, extraperitoneal tissue, and parietal peritoneum.

Question 15

What reinforces the medial two-thirds of the posterior wall?

Answer 15

Conjoint tendon and reflected part of the inguinal ligament.

Question 16

What forms the roof of the inguinal canal?

Answer 16

Arched fibers of the internal oblique and transversus abdominis muscles.

Question 17

What forms the floor of the inguinal canal?

Answer 17

Inguinal ligament and lacunar ligament at the medial end.

Question 18

Which sex has a larger inguinal canal?

Answer 18

Males.

Question 19

What structure passes through the inguinal canal in males?

Answer 19

Spermatic cord.

Question 20

What structure passes through the inguinal canal in females?

Answer 20

Round ligament of the uterus.

Question 21

How does the ilioinguinal nerve enter the inguinal canal?

Answer 21

Through the interval between the external and internal oblique muscles.

Question 22

What are the components of the spermatic cord?

Answer 22

Ductus deferens, testicular and cremasteric arteries, pampiniform plexus, lymph vessels, nerves, and remains of processus vaginalis.

Question 23

What are the coverings of the spermatic cord?

Answer 23

Internal spermatic fascia, cremasteric fascia, and external spermatic fascia.

Question 24

What is the internal spermatic fascia derived from?

Answer 24

Fascia transversalis.

Question 25

What is the cremasteric fascia derived from?

Answer 25

Internal oblique and transversus abdominis muscles.

Question 26

What is the external spermatic fascia derived from?

Answer 26

External oblique aponeurosis.

Question 27

Why is the inguinal canal a site of weakness?

Answer 27

Due to its anatomical position and presence of openings.

Question 28

What prevents herniation through the inguinal canal?

Answer 28

Various protective mechanisms such as the flap valve and shutter mechanisms.

Question 29

What is the flap valve mechanism?

Answer 29

Approximation of the anterior and posterior walls of the canal when intra-abdominal pressure rises.

Question 30

How is the superficial inguinal ring reinforced?

Answer 30

By the conjoint tendon and reflected part of the inguinal ligament.

Question 31

What protects the deep inguinal ring?

Answer 31

Fleshy fibers of the internal oblique muscle.

Question 32

What is the shutter mechanism of the internal oblique?

Answer 32

The internal oblique muscle contracts and approximates the roof to the floor.

Question 33

What is the ball valve mechanism?

Answer 33

Contraction of the cremaster muscle plugging the superficial inguinal ring.

Question 34

What is the slit valve mechanism?

Answer 34

Contraction of the external oblique approximating the crura of the superficial inguinal ring.

Question 35

How does intra-abdominal pressure affect the inguinal canal?

Answer 35

It activates the protective mechanisms to prevent herniation.

Question 36

What is the role of hormones in the inguinal canal?

Answer 36

They may maintain the tone of the inguinal musculature.

Question 37

What does the inguinal canal develop from?

Answer 37

The passage of the gubernaculum through the abdominal wall.

Question 38

Where does the gubernaculum extend from and to?

Answer 38

From the caudal end of the developing gonad to the labioscrotal swelling.

Question 39

Why is man predisposed to inguinal hernia?

Answer 39

Evolutionary changes due to upright posture.

Question 40

How has the iliac crest changed in humans?

Answer 40

It has grown forwards into the external oblique muscle, limiting its role in reinforcing the inguinal canal.

Question 41

How has the internal oblique and transversus abdominis changed?

Answer 41

Their origin shifted, reducing their role as a sphincter.

Question 42

Why is the crural passage wider in humans?

Answer 42

Due to hip bone and pelvic growth, predisposing to femoral hernia.

Question 43

What is a hernia?

Answer 43

Protrusion of abdominal contents through its walls.

Question 44

What is an external hernia?

Answer 44

Hernia that protrudes through the abdominal wall.

Question 45

What is an internal hernia?

Answer 45

Herniation within the peritoneal cavity.

Question 46

What are the components of a hernia?

Answer 46

Sac, contents, and coverings.

Question 47

What is the sac of a hernia?

Answer 47

Protrusion of peritoneum containing herniated contents.

Question 48

What are the contents of a hernia?

Answer 48

Coils of intestine, omentum, or other viscera.

Question 49

What is irreducible hernia?

Answer 49

When the herniated loop does not return to the abdomen.

Question 50

What is obstructed hernia?

Answer 50

When the intestinal contents cannot move forward due to narrowing.

Question 51

What is strangulated hernia?

Answer 51

When arterial supply is cut off, leading to necrosis.

Question 52

What are the types of abdominal hernia?

Answer 52

Internal and external hernias.

Question 53

Where do internal hernias commonly occur?

Answer 53

Epiploic foramen, lesser sac, paraduodenal recesses.

Question 54

What are the types of external hernias?

Answer 54

Umbilical, paraumbilical, femoral, inguinal, epigastric, incisional, lumbar.

Question 55

What is congenital umbilical hernia?

Answer 55

Due to non-return of midgut loop to the abdominal cavity.

Question 56

What is acquired infantile umbilical hernia?

Answer 56

Due to weakness of the umbilical scar.

Question 57

What is paraumbilical hernia?

Answer 57

Herniation through the linea alba near the umbilicus.

Question 58

Which type of hernia is more common in females?

Answer 58

Femoral hernia.

Question 59

Where is the neck of a femoral hernia located?

Answer 59

Below and lateral to the pubic tubercle.

Question 60

What is inguinal hernia?

Answer 60

Protrusion of intestine through the inguinal wall or canal.

Question 61

What is indirect inguinal hernia?

Answer 61

Hernia passing through deep ring, inguinal canal, and superficial ring into the scrotum.

Question 62

Who is more prone to indirect inguinal hernia?

Answer 62

Male infants and children.

Question 63

What is direct inguinal hernia?

Answer 63

Hernia passing through the posterior wall of the inguinal canal.

Question 64

Where does direct inguinal hernia occur?

Answer 64

Hesselbach�s triangle or posterior wall of inguinal hernia.

Question 65

What is epigastric hernia?

Answer 65

Hernia through the linea alba above the umbilicus.

Question 66

What is incisional hernia?

Answer 66

Hernia through a previous surgical incision.

Question 67

What is lumbar hernia?

Answer 67

Hernia through the lumbar triangle in the posterior abdominal wall.