Peritoneum Flashcards
What is the peritoneum?
It is a single layer of squamous epithelium (mesothelium) that is derived from the mesoderm layer of the developing embryo.
The peritoneum forms a ______ membrane.
Serous membrane which invests most of the digestive, reproductive organs, and the walls of the abdominal and pelvic cavities
What is the peritoneal cavity?
The complete coverage of all organs by the peritoneum in the abdominal and pelvic cavities creates a mesothelial-lined cavity (or sac) called the peritoneal cavity, which is void of exposed organs
What are the exceptions to the peritoneal cavity covering?
Fimbriae and the opening of the uterine tube.
The peritoneal cavity exists as a potential space that contains only ________ and occasional macrophages in the healthy person.
Serous fluid
As the developing embryo elongates and the primitive gut begins to the close, the future abdominal and pelvic cavities are divided rostral-caudally by:
A double-lined mesothelium (dorsal-mesoduodenum and dorsal mesocolon) that has its origin at the base of the aorta and its insertion at the midline above the umbilicus on the ventral surface (ventral-mesogartrium)
Clusters of cells in the dorsal mesogastrium give rise to:
The pancreas and the spleen
Clusters of cell in the ventral mesogastrium gives rise to:
The liver
The peritoneum consists of what two layers?
- Parietal layer - lines the abdominal and pelvic walls
2. Visceral layer - invests the viscera of the abdominal and pelvic organs
Is the peritoneal cavity open or closed in males?
It is closed - there is no natural communication between the peritoneal cavity and the outside environment in the male.
Is the peritoneal cavity open or closed in females?
It is open - the opening of the uterine tube is not covered by peritoneum. This accommodates the transport of the ovulated egg from the peritoneal cavity into the uterine tubes. There is direct communication from the peritoneal cavity to the outside environment via uterine tube-uterus-cervix-vagina.
What is the significance of the peritoneal cavity being open in females?
It is a pathway for potential spread of infections that may arise anywhere along the urogenital tract
What is the parietal peritoneum separated from the body wall by?
The extra peritoneal connective tissue
What specialized structures does the peritoneum form?
Mesentery, omentum, ligament, and peritoneal folds
What is the mesentery?
Double layer of peritoneum attached to the body wall that encloses part or all of an organ and its supply of vessels (arteries, veins, and lymphatics) and nerves. An organ suspended by mesentery is mobile.
What are some examples of mesentery?
Transverse mesocolon, the mesentery, mesoappendix, and sigmoid mesocolon
What is omentum?
A double-layered fold of peritoneum (mesentery) passing from the stomach and first part of the duodenum to another abdominal organ
What is the Greater omentum?
It attaches to the greater curvature of the stomach (and the first part of the duodenum) and inserts onto the transverse colon
What is the Lesser omentum?
It attaches along the lesser curvature of the stomach and first part of the duodenum and inserts onto the visceral surface (inferior surface) of the liver.
What is important about the greater and lesser omenta?
They are very elastic and can accommodate the movement and stretching of the stomach and transverse colon
What is the peritoneal ligament?
It is defined as a mesentery or omental structure that is strengthened by underlying connective tissue. Ligaments are less susceptible to stretching than omentums and mesenteries and serve as anchoring points for suspended organs
What are some examples of peritoneal ligaments?
Hepatoduodenal, gastrosplenic, splenorenal, and gastrophrenic, and falciform, and the coronary ligament of the liver
What is a peritoneal fold?
A reflection of peritoneum that overlies a structure associated with the body wall. This results in the formation of a defined border over the covered structure.
What are some examples of peritoneal folds?
Median-, medial-, and lateral-umbilical folds
What is the median-umbilical fold remnant of?
The urachus
What is the medial-umbilical fold remnant of?
The umbilical arteries - right and left
What is in the lateral-umbilical fold?
Inferior epigastric vessels - right and left
Structure - organs, vessels, ducts etc - in the abdominal and pelvic cavities are defined as being:
Intraperitoneal or retroperitoneal
What does intraperitoneal mean?
Defines any organ or structure that is suspended by a mesentery, omentum, or ligament into the abdominal or pelvic cavity