Abdomen III - Peritoneum, Omentum & Ligaments Flashcards
The peritoneum is a …
continuous, glistening, slippery & transparent serous membrane
The peritoneum lines….
the abdominalpelvic cavity & invests the viscera
What layers make up the peritoneum?
- parietal peritoneum - lines internal surface of abdominalpelvic wall
- visceral peritoneum - invests viscera (i.e. stomach, intestines)
The peritoneal layers are made of which tissue?
mesothelium
(a layer of simple squamous epithelial cells)
Which blood & lymphatic vasculature supply the peritoneum?
same somatic nerve supply as is the region of the wall it lines
The peritoneum lining the interior of the body wall is sensitive to…
pressure
pain
heat and cold
laceration
Pain from the parietal peritoneum is …
generally well localized
- except for that on the inferior surface of the central part of the diaphragm (innervation is provided by the phrenic nerve)
irritation on the inferior surface of the cenral diaphragm is often referred to what area of the body?
to the C3 - C5 dermatomes over the shoulder
The visceral peritoneum and the organs it covers are served by what blood & lymphatic vasculature, & nerves?
the same blood and lymphatic vasculature and visceral nerve supply
The visceral peritoneum is insensitive to __________
& stimulated by ____________?
insensitive to:
touch
heat and cold
laceration
stimulated primarily by:
** **stretching
chemical irritation
pain from the foregut derivatives is usually experienced in the __________ region?
epigastric
Pain from midgut derivatives is usually experienced in the
___________ region ?
umbilical
Pain from hindgut derivatives is usually experienced in the
___________ region ?
pubic
pain produced in the peritoneum is … ?
- poorly localized
- referred to the dermatomes of the spinal ganglia providing the sensory fibers
The relationship of the viscera to the peritoneum is as follows:
Intraperitoneal organs are almost completely covered with visceral peritoneum (e.g., the stomach and spleen)
Extraperitoneal, retroperitoneal, and subperitoneal organs are outside the peritoneal cavity “external, posterior, or inferior to the parietal peritoneum” and are only partially covered with peritoneum (usually on just one surface).
Organs such as the kidneys are _________________________ and have parietal peritoneum only __________________?
- between the parietal peritoneum and the posterior abdominal wall
- on their anterior surfaces
Organs such as the urinary bladder are _________________________ and have parietal peritoneum only __________________?
- between the parietal peritoneum and the posterior abdominal wall
- only on its superior surface
How is the peritoneal cavity positioned, relative to the abdominal and pelvic cavities?
is within the abdominal cavity and continues inferiorly into the pelvic cavity
What is between the parietal and visceral layers of peritoneum in the peritoneal cavity?
a potential space of capillary thinness
The peritoneal cavity contains no organs. What is contained in the thin film of peritoneal fluid?
it’s is composed of water
electrolytes
other substances derived from interstitial fluid in adjacent tissues
What is the function of peritoneal fluid?
- lubricates the peritoneal surfaces
- enables the viscera to move over each other without friction
- allows the movements of digestion
What infection resistant structures are contained in the peritoneal fluid?
leukocytes and antibodies
How is the peritoneal fluid absorbed ?
absorbed by ymphatic vessels
(particularly on the inferior surface of the diaphragm)
The periotoneal cavity is completely closed in males/females ?
males
Where is the communication pathway in females to the exterior of the body?
through the uterine tubes, uterine cavity, and vagina
The communication pathway from the peritoneal cavity in females is a potential pathway for what?
external infection
What helps prevent peritonitis from the communication pathway in females?
protective mechanisms of the female reproductive tract
- mucous plug
(blocks most things, excep sperm)
- normally present bacteria in vagina
(other bacteria cannot co-exist)
How can the patency of the uterine tubes can be tested clinically?
hysterosalpingography
- a technique in which air or radiopaque dye is injected into the uterine cavity
(normally flows through the uterine tubes and into the peritoneal cavity)
Why do patients undergoing abdominal surgery with large, invasive, open incisions of the peritoneum (laparotomy) experience more pain?
peritoneum is well innervated
(small, laparoscopic incisions or vaginal operations = less painful)
watertight end-to-end anastomoses of intraperitoneal organs (i.e. small intestine) is achievble due to …..?
the covering of peritoneum (serosa)
It is more difficult to achieve watertight anastomoses of _____________________ (i.e. thoracic esophagus)
extraperitoneal structures that have an outer adventitial layer
During surgery, efforts are made to remain outside the peritoneal cavity whenever possible. WHY?
- high incidence of complications such as peritonitis and adhesions
When opening the peritoneal cavity is necessary what is avoided?
contamination of the cavity
Peritonitis
bacterial contamination = infection and inflammation of the peritoneum
- from a laparotomy, penetrated or rupturing of the gut
- allows gas, fecal matter, and bacteria to enter the peritoneal cavity
OR
ulcer perforates the wall of the stomach or duodenum
- spilling acid content into the peritoneal cavity.
What occurs during peritonitis?
- exudation (slow leaking) of serum, fibrin, cells, and pus into the peritoneal cavity
- pain in the overlying skin + increase in the tone of the anterolateral abdominal muscles
What makes generalized (widespread) peritonitis dangerous and perhaps lethal?
- the extent of the peritoneal surfaces
- rapid absorption of material (including bacterial toxins) from the peritoneal cavity
Common symptons of peritonitis include:
severe abdominal pain
tenderness
nausea and/or vomiting
fever
constipation
ridigity of abdominal walls
*formation of any detergent-like substances (i.e. fatty acid + Na = soap) in cavity is lethal*
Identify the numbered structres:
- superior border of diaphragm
- liver
- collected gases due to peritonitis
Major cause of portal hypertension?
consumption of alcohol
Ascites
clinical condition in which one has excess fluid in peritoneal cavity
(ascitic fluid)
Ascites can occur as a result of:
- mechanical injury (may also produce internal bleeding)
- pathological conditions (i.e. portal hypertension=venous congestion)
- widespread metastasis of cancer cells to the abdominal viscera
- starvation (plasma proteins fail to be produced, alter concentration gradients = paradoxically protuberant abdomen)
What abdominal movements usually accompany respiration?
rhythmic movements of the anterolateral abdominal wall
the presence of** peritonitis** or pneumonitis (inflammation of the lungs) can be considered when which movements are present?
- If the abdomen is drawn in as the chest expands (paradoxical abdominothoracic rhythm)
- muscle rigidity is present
What do people with peritonitis do to decrease pain?
- lie with knees flexed = relax anterolateral abdominal muscles
- breath shallowly (+ more rapidly) = reducing the intra-abdominal pressure and pain
Peritoneal Adhesions
- peritoneum is damaged = surfaces become inflamed + sticky with fibrin
- as it heals, fibrin may be replaced with fibrous tissue
- forms abnormal attachments between visceral peritoneum of adjacent viscera
OR
between visceral peritoneum of viscera and parietal peritoneum of the adjacent abdominal wall
Adhesions (scar tissue)
- may form after an abdominal operation
- limit normal movements of the viscera
- may cause chronic pain or emergency complications (i.e. intestinal obstruction when gut is twisted around an adhesion (volvulus))
Adhesiotomy
surgical separation of adhesions
Abdominal Paracentesis
Treatment of generalized peritonitis
- removal of the ascitic fluid
- administration of large doses of antibiotics (if infection is present)
- occasionaly more localized accumulations of fluid removed for analysis
paracentesis = surgical puncture of the peritoneal cavity for the aspiration or drainage of fluid
What is the procedure for abdominal paracentesis?
- injection of a local anesthetic agent
- needle or trocar and a cannula are inserted through anterolateral abdominal wall into peritoneal cavity through the linea alba (for example)
- needle is inserted superior to the empty urinary bladder and in a location that avoids the inferior epigastric artery
Intraperitoneal Injection (I.P. Injection)
- can be absorbed rapidly
- anesthetic agents injected into peritonal cavity
What factors allow the peritoneal membrane to be so absorbant?
- semipermeable membrane
- extensive surface area
- overlies blood & lymphatic capillary beds
Peritoneal Dialysis
- soluble substances + excess water removed from system by transfer across the peritoneum
- use a dilute sterile solution introduced into peritoneal cavity on one side and drained from the other side
- solutes + water are transferred between blood and peritoneal cavity due to concentration gradients between the two fluid compartments
- usually only temporary; changes in mesothelial cells of peritoneum + underlying connective tissue = progressively ineffective
What is a mesentery?
- double layer of peritoneum (invagination of the peritoneum by an organ) = continuity of the visceral and parietal peritoneum
- provides a means for neurovascular communication between the organ and the body wall
What 2 structures are connected by a mesentery?
intraperitonel organ + body wall (usually posterior abdominal wall)
Which mesentery is usually referred to simply as “the mesentery”?
small intestine mesentery
mesenteries related to other specific parts of the alimentary tract are named accordingly
What is the structural make-up of a mesentery?
a core of connective tissue containing:
blood and lymphatic vessels
nerves
lymph nodes
fat
What is an omentum?
a double-layered extension (fold) of peritoneum that passes from:
stomach + proximal part of the duodenum
—>
adjacent organs in the abdominal cavity
Where is the greater ometum?
prominent peritoneal fold that hangs down (like an apron) from the greater curvature of the stomach and the proximal part of the duodenum
- after descending: folds back +at taches to anterior surface of the transverse colon and its mesentery
Where is the lesser omentum?
- connects lesser curvature of the stomach and proximal part of the duodenum to the liver
- also connects the stomach to a triad of structures that run between the duodenum and liver in the free edge of the lesser omentum
peritoneal ligament
a double layer of peritoneum that connects an organ with another organ or to the abdominal wall
What structures are the liver connected to, and by what?
- Anterior abdominal wall by the falciform ligament
- Stomach by the hepatogastric ligament
- (membranous portion of lesser omentum)*
- Duodenum by the hepatoduodenal ligament
- (thickened free edge of lesser omentum; conducts the portal triad)*
What is the portal triad?
portal vein
hepatic artery
bile duct
The hepatogastric and hepatoduodenal ligaments are continuous parts of_____________________?
the lesser omentum
Which structures are the stomach connected to, and by what?
- Inferior surface of diaphragm by the gastrophrenic ligament
- Spleen by the gastrosplenic ligament
(gastrolienal ligament; reflects to the hilum of the spleen)
- Transverse colon by the gastrocolic ligament
what are bare areas?
- the area on intraperitoneal organs NOT covered by visceral peritoneum
- allow entry/exit of mesenteries, omenta, and ligaments that convey the neurovascular structures
What is a peritoneal fold?
- reflection of peritoneum raised from the body wall by underlying blood vessels, ducts, and obliterated fetal vessels
- Some peritoneal folds contain blood vessels and bleed if cut
- (ex. lateral umbilical folds –> inferior epigastric arteries)*
Peritoneal folds
(image)
What is a peritoneal recess (or fossa)?
a pouch of peritoneum formed by a peritoneal fold
What are the Functions of the Greater Omentum?
- prevents the visceral peritoneum from adhering to the parietal peritoneum
- considerable mobility; moves around peritoneal cavity with peristaltic movements of the viscera
- often forms adhesions adjacent to an inflamed organ, sometimes walling it off = protecting other viscera
- also cushions the abdominal organs against injury + insulation against loss of body heat
Abscess Formation
circumscribed collection of purulent exudate in the subphrenic recess
can be caused by:
- perforation of a duodenal ulcer
- rupture of the gallbladder
- perforation of the appendix
abscess may be walled inferiorly by adhesions
Why are peritoneal recesses clinically significant in the spread of pathological fluids?
(ex. pus)
recesses determine the extent and direction of the spread of fluids that may enter the peritoneal cavity when an organ is diseased or injured
