Parietal Peritoneum: Anatomy And Function

Abdominal Cavity And Peritoneum

Question 1. Give the boundaries of the abdominal cavity.
Answer:

The abdominal cavity is the largest cavity of the body, located within the abdomen and pelvis.

Abdominal cavity Boundaries:

• Roof: Diaphragm
• Inferior: Pelvic diaphragm
• Posterior: Posterior abdominal wall
• Anterior: Anterior abdominal wall

Read And Learn More: Anatomy Question And Answers

Lateral (on each side): Flank (i.e., an abdominal wall between the rib cage and iliac crest).

Abdominal Cavity Regions

Question 2. Write a short note on Addison’s plane (i.e. transpyloric plane). 
Answer:

Addison’s Plane

• Addison’s plane  is an imaginary horizontal plane that passes through the tips of the 9th costal cartilage anteriorly and the lower border of the L1 vertebra posteriorly.
• Addison’s plane  is situated halfway between the suprasternal notch and the upper border of the pubic symphysis
• Addison’s plane  is the key plane of the abdomen.

Addison’s Plane Clinical importance

Clinically it is important because it passes through several important abdominal structures.

Abdominal Cavity Regions

For examples:

• Pylorus
• Neck of pancreas
• Hila of kidneys
• Formation of portal vein
• Origin of superior mesenteric artery

Question 3. Give a brief account of 9 regions of the abdomen. 
Answer:

Regions Of The Abdomen

For descriptive purposes, the Clinicians divide the abdominal cavity into 9 regions by 2 vertical and 2 horizontal planes drawn on the anterior abdominal wall.

1. The two vertical planes are: Right and left midclavicular planes.
2. The two horizontal planes are the Transpyloric and trans tubercular planes.
3. The 9 regions marked out in this way are arranged in 3 zones: Upper, middle, and lower.

Abdominal Cavity Regions

These regions are given in the box below:

Question 4. Give a brief account of 4 quadrants of the abdomen. 
Answer:

Quadrants Of The Abdomen

Some clinicians divide the abdominal cavity into 4 quadrants by two plans:

• The transumbilical plane, passing horizontally through the umbilicus, and
• The median vertical plane intersects the transumbilical horizontal plane at the umbilicus.

The 4 quadrants marked in this way are:

• Right upper quadrant
• Left upper quadrant
• Right lower quadrant
• Left upper quadrant

Quadrants Of Abdomen And Organs

Parietal Peritoneum

Question 5. Describe the Peritoneum under the following headings
Answer:

1. Peritoneum Definition
2. Peritoneum Layers and
3. Peritoneum Functions.

Peritoneum Definition

• The peritoneum is a large sac of serous membrane lined with mesothelium within the abdomen.
• It is a closed sac in males, while in females it communicates to the exterior through the vagina.

Peritoneum Layers

The serous sac of the peritoneum is invaginated by the number of abdominal viscera.

 Quadrants Of Abdomen And Organs

Consequently, the peritoneum is divided into two layers:

1. Outer parietal layer
2. Inner visceral layer.

The parietal peritoneum is pain-sensitive to cut and temperature because it is innervated by the somatic nerves, whereas the visceral peritoneum is pain-insensitive to cut and temperature because it is innervated by the autonomic nerves.

Peritoneum Functions

• Facilitation of movements of viscera
• Protection of viscera
• Absorption and dialysis of peritoneal fluid
• Facilitates healing and formation of adhesion
• Storage of fat

Note:

Properties of peritoneum which make peritoneal dialysis possible:

• Peritoneum acts as a semipermeable membrane.
• Peritoneum has a large surface area.
• Peritoneum absorbs the waste products from blood capillaries.

Lesser Omentum And Greater Omentum

Question 7. Write a short note on greater omentum. 
Answer:

Greater Omentum:

The greater omentum is a large fold of peritoneum studded with fat that hangs down from greater curvature of the stomach like an apron.

Greater omentum Features

• Greater omentum covers the loops of intestines to a variable extent:
• Greater omentum is made up of 4 layers of peritoneum, which are fused together.
• Greater omentum extends from the greater curvature of the stomach to the transverse colon.

Greater omentum Content

The contents of greater omentum are

• Adipose tissue
• Aggregation of macrophages, forming dense patches called milky spots
• Right and left gastroepiploic arteries and accompanying veins.

Lesser Omentum And Greater Omentum

Greater omentum Functions

• Storehouse of fat.
• Limits the spread of infection by moving to the site of infection and sealing it off from the surrounding area; hence, it is also called the policeman of the abdomen.
• Used as graft by surgeons.

Question 8. Draw a labeled diagram to show the vertical Tracing of the Peritoneum.
Answer:

Vertical tracing of the peritoneum: