General Surgery - Overview Of Hernias

Front 1

What is the hiatus?

Back 1

A hiatus means a break or hole.

Generally speaking, the anatomic hiatus, which is a general term, usually refers to the esophageal hiatus, which is the break in the diaphragm through which the esophagus passes from the thorax into the abdomen.

Front 2

What is a hiatus hernia?

Back 2

A hiatus hernia or hiatal hernia is the protrusion (or herniation) of the upper part of the stomach into the thorax through a tear or weakness in the diaphragm.

Front 3

What is an aponeurosis?

Back 3

An aponeurosis is a layer of flat broad tendon.

Front 4

Describe the anatomy of the abdominal wall.

Back 4

Medially, the only muscle of the anterior abdominal wall is the rectus sheath. There are no muscles passing above or below it.

In place of muscles, however, are the aponeuroses of the external and internal obliques and transversus abdominus muscles. These aponeuroses enclose the rectus muscle, forming the rectus sheath.

Above the arcuate line:
-the aponeurosis of the external oblique passes anteriorly to the rectus muscle
-1/2 of the aponeurosis of the internal oblique also passes anteriorly
-together these two layers form the anterior rectus sheath
-the other half of the internal oblique aponeurosis, together with the transversus aponeurosis, form the posterior part of the rectus sheath

Below the arcuate line, the aponeuroses of all three muscles pass in front of the rectus (i.e. there is no longer a posterior rectus sheath and the rectus muscle simply sits on a thin layer of fascia)

Laterally, the abdominal wall is formed by three muscle layers. From superficial to deep these are the external obliques, the internal obliques, and the transversus abdominus.

Front 5

Which tissues form the posterior part of the rectus sheath ABOVE the arcuate line?

Back 5

1) 1/2 of the internal oblique aponeurosis (other 1/2 passes anteriorly)

2) Aponeurosis of transversus abdominus muscle.

Front 6

Which tissues form the posterior part of the rectus sheath BELOW the arcuate line?

Back 6

Trick question because by definition there is no posterior rectus sheath below the arcuate line. The muscle just sits on a thin layer of fascia (what's this called?).

Front 7

Name the three muscle layers of the lateral abdominal wall, from superficial to deep.

Back 7

1) External oblique
2) Internal oblique
3) Transversus abdominis

Front 8

In which direction do the external oblique muscles run? The internal obliques?

Back 8

External obliques: inferomedially

Internal obliques: inferolaterally

Front 9

What is the significance of the arcuate line?

Back 9

Above the arcuate line there's a posterior rectus sheath formed by the aponeuroses of the internal oblique and transversus abdominis muscles.

Front 10

What is the linea alba?

Back 10

The linea alba is a tendonous raphe (seam) that runs from the sternum to the pubic symphysis.

It is the point of fusion of the aponeuroses of the muscles of the lateral abdominal wall (internal oblique, external oblique, tranversus abdominis)

Front 11

True or false: the transversus abdominis lies between the external and internal obliques.

Back 11

False

The transversus abdominis muscle lies beneath both of these muscles.

Front 12

What is an incarcerated hernia?

Back 12

An incarcerated hernia is one that cannot be easily externally reduced.

In other words, if you can't push it back in with your fingers, it's incarcerated.

Front 13

What is a strangulated hernia?

Back 13

A strangulated hernia is a hernia in which the blood vessels are compressed.

Strangulation results in ischemia and necrosis.