Block 2 abdomen part lll Flashcards
peritonium
peritoneum is a serous membrane that lies the peritonium (abdominal) cavity and invests the abdominal viscera.
parietal peritoneum lines the internal surface of the abdominiopelvic walls.
The parietal peritoneum is served by the same blood supply and somaic innervation as the region of the wall it lines. it is sensitive to pressure, pain, and temperature and pain sensations are typically well localized.
visceral peritoneum invests certain abdominal organs (e.g. the stomach and spleen). The visceral peritoneum is searved by the same blood supply and visceral afferent innervation as the organs it covers. therefore it is insensitive to temperature, pain, and laceration. It is mainl sstimulated nby stretching and chemical irritants. The pain is poorly localized and its manifestation is related to the embryological development of the organ it covers (i.e. foregut derivatives to epigastric region, midgut to the umbilical region, and hindguy to the pubic region.
The peritoneal cavity is within the abdominal cavity and represents a potential space between the parietal and visceral layers of peritoneum.
Innervations of the peritoneum
Parietal peritoneum – same somatic nerve supply
as the region of the wall it lines (T7-L1), like the wall
of the abdomen it is sensitive to pressure, pain, heat,
cold & laceration. The pain is generally well
localized.
Visceral peritoneum – parasympathetic – Vagus n.,
sympathetic – Splanchnic nn. & sympathetic trunk.
It is insensitive to touch, heat, cold, and laceration. It is
stimulated by stretch and chemical irritation, the pain
produced is poorly localized, and is usually referred
pain to the dermatomes supplied by the spinal ganglia
providing the sensory fibers (afferents follow path of
efferent sympathetics back to spinal ganglia
Intraperitoneal Organs:
Intraperitoneal Organs: Are completely covered with visceral peritoneum (e.g. stomach and spleen). Intraperitoneal organs have a mesentery.
Retroperitoneal Organs:
Retroperitoneal Organs: Are external, posterior, inferior to the parietal peritoneum and thus are only partially covered with peritoneum (i.e. usually on one side only). Examples include the kidneys and the bladder.
A mesentery
A mesentery: is a double layer of peritoneum that occurs as the result of an invagination of the peritoneum by an organ and constitues a continuity between the visceral and parietal layers of peritoneum. It provides a conduit for neurovascular structures passing between the organ and the body wall.
The greater omentum
The greater omentum precents the visceral and parietal peritoneum from sticking together. It was very mobile and moves with the peristaltic movements of the GI tracts, it often forms adhesions adjacent to inflamed organs, sometimes walling them off. This is why in a patient or cadaver you may find the greater omentum displaced from the “normal” position illustrated in textbooks.
