Difference between revisions of "Peritoneal Cavity - Anatomy & Physiology"
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==Structure & Histology== | ==Structure & Histology== | ||
*The peritoneum is smooth and clear in the healthy animal. | *The peritoneum is smooth and clear in the healthy animal. | ||
| − | *It consists of a thin layer of loose connective tissue covered by a single layer of [[Mesothelial cells|mesothelial cells]]. | + | *It consists of a thin layer of loose connective tissue covered by a single layer of [[Mesothelial cells|mesothelial cells]]. Collectively, the connective tissue and peritoneum are referred to as the '''serosa'''. |
**Mesothelial cells are simple squamous and of mesodermal origin. | **Mesothelial cells are simple squamous and of mesodermal origin. | ||
| + | *There are two layers of peritoneum lining the abdomen. | ||
| + | **The layer in contact with the abdominal wall | ||
*Many species have lymphoid tissue aggregates and fixed phagocytes in the omentum that are not covered by mesothelial cells | *Many species have lymphoid tissue aggregates and fixed phagocytes in the omentum that are not covered by mesothelial cells | ||
*''NB Post mortem change and autolysis result in increased volumes of red-brown fluid in the abdomen, not associated with other pathology, no roughening of surfaces of organs or peritoneum.'' | *''NB Post mortem change and autolysis result in increased volumes of red-brown fluid in the abdomen, not associated with other pathology, no roughening of surfaces of organs or peritoneum.'' | ||
Revision as of 16:03, 22 July 2008
Introduction
The peritoneum is the serous membrane which lines the abdominal cavity. It is a type of loose connective tissue covered by mesothelium. Extensions of the peritoneum form the mesenteries that support the abdominal contents. It functions to lubricate abdominal viscera , enhance the immune response and wall off infection in the abdomen to prevent peritonitis.
Structure & Histology
- The peritoneum is smooth and clear in the healthy animal.
- It consists of a thin layer of loose connective tissue covered by a single layer of mesothelial cells. Collectively, the connective tissue and peritoneum are referred to as the serosa.
- Mesothelial cells are simple squamous and of mesodermal origin.
- There are two layers of peritoneum lining the abdomen.
- The layer in contact with the abdominal wall
- Many species have lymphoid tissue aggregates and fixed phagocytes in the omentum that are not covered by mesothelial cells
- NB Post mortem change and autolysis result in increased volumes of red-brown fluid in the abdomen, not associated with other pathology, no roughening of surfaces of organs or peritoneum.
Function
- Small volume of clear fluid for lubrication - in equilibrium with plasma but doesn't contain high molecular weight molecules like fibrinogen
Vasculature
Innervation
Lymphatics
Histology
- Have microvili on their surface
- Very fragile but regenerate very quickly
- High fibrinolytic activity - protects against the formation of adhesions
- Show reactive change with inflammation or effusions
- May be confused with neoplastic cells
Species Differences
- Peritoneum is normally smooth and clear,
- Small volume of clear fluid for lubrication - in equilibrium with plasma but doesn't contain high molecular weight molecules like fibrinogen
- Small animals
- Low volume of clear straw coloured fluid
- Specific gravity <1.015 to 1.018
- Total protein 25-39g/L
- Nucleated cell count <3x10e9/L
- Mesothelial cells/macrophages