Peritoneal cavity Flashcards
what is the peritoneal cavity?
potential space between parietal & visceral peritoneum
what does the peritoneal cavity contain?
a thin film of peritoneal fluid, which consists of water, electrolytes, leucocytes, antibodies
what are the 2 main functions of the peritoneal cavity?
- lubricant, enabling free movement of abdominal viscera
2. antibodies fight infection
why is the peritoneal cavity referred to as a potential space?
only of capillary thinness
because excess fluid can accumulate in peritoneal cavity resulting in clinical condition of ascites
what can the peritoneal cavity be divided into?
greater and lesser peritoneal sacs
what constitutes the greater sac?
majority of the peritoneal cavity
what is the lesser sac also known as?
omental bursa
where is the lesser sac?
smaller & lies posterior to stomach & lesser omentum
what is the greater sac divided by and into what?
2 compartments by mesentery of transverse colon (transverse mesocolon) into supracolic and infracolic compartment
what is the supracolic compartment and where is it?
lies above the transverse mesocolon
contains stomach, liver, spleen
where is the infracolic compartment and what does it contain?
lies below the transverse mesocolon & contains the small intestine, ascending & descending colon
what is the infracolic compartment further divided into?
left & right infracolic spaces by the mesentery of the small intestine
what is the supra and infracolic compartments connected by?
paracolic gutters - lie between the posterolateral abdominal wall & lateral aspect of the ascending or descending colon
what are subphrenic spaces?
subphrenic spaces are rececsses in the greater sac of the peritoneal cavity between the anteriosuperior diaphragmatic surface of the liver and the diaphragm
what do subphrenic spaces separated into? what is it separated by?
right and left subphrenic spaces by the falciform ligament of the liver
when do subphrenic abscesses occur?
as a result of the accumulation of pus in the left or right subphrenic space as a consequence of peritonitis
where is subphrenic abscesses more common? why?
more common on the right side: increased frequency of appendicitis and ruptured duodenal ulcers
where is the omental bursa (lesser sac) located and what does it allow?
lies posterior to stomach & lesser omentum
allows stomach to move freely against the structures posterior & inferior to it
what is the omental bursa connected with the greater sac through?
the greater sac through an opening in the omental bursa, the epiploic foramen
where is the epiploic foramen?
situated posterior to the free edge of the lesser omentum (hepatoduodenal ligament)
why does the peritoneal cavity differ between sexes? what is the significance of this area?
due to the pelvic organs (most distal portion of cavity, so any infected fluid is likely to collect here)
describe the structure of the peritoneal cavity in males
rectovesical pouch is a double folding of peritoneum between rectum & bladder, peritoneal cavity is completely closed in males
describe the rectouterine pouch (pouch of Douglas) in females
a double folded extension of the peritoneum between the rectum & posterior wall of the uterus
what is the vesicouterine pouch is females?
a double fold of peritoneum between the anterior surface of the uterus & bladder
is the peritoneal cavity closed in females? why?
no, because the abdominal ostia of the uterine tubes opens into the peritoneal cavity, providing potential pathway between the female genital tract and the peritoneum
what does the lack of closure in the peritoneal cavity in females mean?
infections of the vagina, uterus & uterine tubes may result in infection & inflammation of the peritoneum (peritonitis).
how frequent is peritonitis? why?
rare, due to presence of a mucous plug in the external os (opening) of the uterus which prevents the passage of pathogens but allows sperm to enter the uterus
what is culdocentesis?
extraction of fluid from the rectouterine pouch (pouch of Douglas) through a needle inserted through the posterior fornix of the vagina
when can a culdocentesis be used?
used to extract fluid from the peritoneal cavity or to drain a pelvic abscess in the rectouterine pouch
what is a paracentesis?
a procedure used to drain fluid from the peritoneal cavity
a needle is inserted through the anterolateral abdominal wall into the peritoneal cavity
how must the needle be inserted in paracentesis?
superior to the urinary bladder and the clinician must take care to avoid the inferior epigastric artery
what is a paracentesis used for?
to drain ascitic fluid, diagnose the cause of ascites and to check for certain types of cancer which may metastasise via the peritoneum e.g. liver cancer
what is ascites?
accumulation of excess fluid in the peritoneal cavity
when can ascites occur?
in conjunction with infection & peritonitis, however, more commonly caused by portal hypertension secondary to cirrhosis of liver
what are other causes of ascites?
malignancies of the GI tract, malnutrition, heart failure, mechanical injuries resulting in internal bleeding
how do patients with ascites present?
with distended abdomen, discomfort, nausea, dyspnoea
what does the paracolic gutters provide?
a route for the flow ascitic fluid, and for the spread of intraperitoneal infections & cancer metastses
how are patients with peritonitis often positioned? why?
in a sitting position (at least 45 degree angle) to encourage the flow of ascitic fluid into the pelvis where toxins are absorbed more slowly
what is peritonitis?
infection and inflammation of the peritoneum
when can peritonitis occur?
as a result of bacterial contamination during a laparotomy (open surgical incision of the peritoneum) or it can occur secondary to an infection elsewhere in the GI tract, e.g. burst appendix, acute pancreatitis or gastric ulcer eroding through the wall of the stomach
what happens during peritonitis?
exudation of fluid into the peritoneal cavity
what does the patient experience with peritonitis? what does the body do?
pain and tenderness of the overlying skin
the anterolateral abdominal muscles contract to protect the viscera (guarding)
What are other symptoms of peritonitis?
fever, nausea, vomiting, constipation
how do patients with peritonitis appear? why?
lie with knees flexed in an effort to relax the anterolateral abdominal wall muscles
what is generalised peritonitis?
when peritonitis is widespread in the abdominal cavity
what can generalised peritonitis lead to?
sepsis and therefore must be treated as an emergency or it can be fetal
