Peritoneum Anatomy Flashcards
3 serous membranes in the body
peritoneum
pericardium
pleura
Where is the peritoneum (and whats a fun fact about it)
serous membrane lining the abdominal, cranial pelvic, and scrotal cavities (and organs within)
its the largest and longest membrane in the body
four Functions of the peritoneum
friction reduction
Free movement as in mesentery
Fixation as by the ligaments
Fat storage as in omentum
What is included in the retroperitoneal
kidneys, adrenal glands, ureters, aorta, lumbar lymph nodes
What do the ectoderm, mesoderm, coelom, and endoderm become in the gut?
Ecto: body wall
Meso: peritoneum (parietal and visceral)
Coelom: peritoneal cavity
Endoderm: gut tube
Clinical significance of retroperitoneal
trauma to kidneys would cause blood/urine to accumulate in retroperitoneal space
these fluids can’t be diagnosed by palpation or abdominocentesis - this can result in delay in diagnosing and cause significant kidney damage
Abdominal cavity vs peritoneal cavity
Abdominal: entire space within abdomen- includes organs, nerves, peritoneum, mesenteries
Peritoneal: between visceral and parietal peritoneum - contains only a lil serous fluid
When is peritonitis more common?
in females due to openings (2) near oviducts
Clinical significance of fluid in peritoneal cavity
If no serous fluid or peritonitis or rough handling → adhesions →
impair movement of abdominal organs →
impair function
potential spaces under normal vs pathological conditions
normal= barely none just to separate
pathological= separate and create a space filled with fluid
What connects the peritoneum
dorsal and ventral mesentery
What are the mesenteries
A type of Connecting Peritoneum … wide, double layered
• Connects: Intestinal & Reproductive tracts with the abdominal wall (think mesoduodenum, mesorectum, mesovarian, meso… etc.)
• Contain blood vessels, lymphatics & nerves
Umbilical herniation and the length of the mesenteries?
herniation-> rotation-> retraction of gut tube
Gut tube growth exceeds that of the body cavity→
• Herniation through the incomplete wall → Two rotations of gut loops.
• body cavity enlarges → return of gut.
Crowding of the viscera
(parts retracted early are crowded by those coming in later.)
fixed > mobile viscera
Fixed viscera
Early viscera are packed tightly against body wall by the portions of the gut that enter later, so their mesenteries are partially fuse with dorsal body wall.
• So these mesenteries are short and called fixed viscera (Stomach & duodenum cranially, Ileum, cecum and all three parts of the colon (caudally))
Mobile Viscera
The regions of the gut that are retracted late, mainly the jejunum, are not crowded and retain their longer mesenteries
length of mesentery determines…
ease of access in surgery
jejunum = easy access, stomach = large incision
what develops in the ventral vs dorsal mesentery
dorsal = spleen
ventral = liver
What mesentery surrounds the liver (in the ventral mesentery)
lesser omentum (dorsal)
peritoneal ligaments of the liver (falciform, coronary, and triangular ligg.)
Describe the root of mesentary
L2- dorsal body wall - attaches mesojejunum and mesoileum
Thick: contains cranial mesenteric artery, intestinal lymphatics, autonomic n. plexus
is the mesentery long or short in the ruminant?
short
Where is the omentum?
passes from stomach to other organs or to the abdominal wall
lesser and greater omentum
connections of the lesser omentum
liver to lesser curvature of the stomach
covers papillary process on caudate liver lobe
greater omentum attachments
none on caudal border- lift that shit out
remnant of dorsal mesogastrium - enlarges and folds in on itself
2 sheets - superficial and deep (each sheet has 2 layers)
What is the omental bursa
subdivision of the peritoneal cavity enclosed by the greater and lesser omentum
- It is a potential space and is collapsed in life
what are the MANY clinical significances of epiploic (omental) foramen? (4)
site of intestinal herniation or entrapment of colon and subsequent colic in HORSES
easiest way to locate the portal vein in surgery
bleeding from liver/cystic artery can be controlled by placing finger over epiploic foramen to occlude hepatic a. and portal vein.
if loop of intestines passed through foramen and strangulated- cannot be cut, bowl must be decompressed by a needle to pull out
What is the epiploic foramen? and what are its boundaries?
aka omental foramen
short passage between the omental bursa and the main peritoneal cavity
• Found at the BASE of the CAUDATE LOBE of the liver in all domestic animals.
dorsal- caudal vena cava
ventral: portal vein
caudal: hepatic artery in mesoduodenum
How do find epiploic foramen
right side of liver- lift caudate lobe
locate caudal vena cava and portal vein
put a figer between 2 veins to reach into omental bursa
Greater omentum species difference
carnivores and ruminants: very developed
equine: poorly developed
in carnivores a ventral surgical incision into the greater omentum reveals…
liver, spleen, bladder
peritoneum should not be sutured separated when closing abdominal incision and should be includes in other sutured layers = less trauma= better closure
clinical importance of the greater omentum
- very mobile and vascular
- policeman of the abdomen - limits infection
- can be removed without impairing health
-will not regenerate if removed
the ______ carried the umbilical arteries and vein in the fetus
ventral peritoneal folds
The falciform ligament
umbilicus & passes to the liver.
• attached to the LINEA ALBA
• In fetus, carried the umbilical vein
- can complicate closure of abdominal incision in cranial part
Note: The falciform ligament is thus the mesentery of the left umbilical vein.
adipose tissue from the falciform ligament contains…
a high concentration of adult stem cells
In cats the ligament is less fatty
What are the remnants of the ventral mesentery
falciform ligament, median and lateral ligaments of urinary bladder
Median ligament of the urinary bladder
contains urachus in the fetus
attaches bladder to ventral abdomen
lateral ligament of the urinary bladder
attaches lateral bladder to lateral abdominal walls
in fetus, carries umbilical arteries (turns into round ligaments of bladder in adult)
the umbilical arteries turn into…
round ligaments of bladder R/L
3 mesenteries and ligaments of the urinary bladder
median ligament
lateral ligaments (r/L)
What is a ligament
Ligament is a band of fibrous tissue connecting bones or cartilages (e.g., collateral lig. of the stifle)
• Ligament is a cordlike remnants of fetal tubular structures that are non-functional after birth (e.g.,
ligamentum arteriosum, round lig. of liver, round ligaments of urinary bladder)
- fixes organs via channels or vessels
connecting peritoneum - ligaments
a type of connecting peritoneum - narrow, double layered
passes from a wall to organ, (or organ to organ)
fix organs as a channel or vessels and nerves
connecting peritoneum - what is a fold
little to no blood vessels
between 2 visceral organs
innervation of parietal peritoneum
somatic nerve
(sensory innervation = segmental spinal nerves)
very sensitive to irritation and will cause local pain
innervation of diaphragm
phrenic nerve
innervation of visceral peritoneum
autonomic nerves
sensitive to stretching
4 peritoneal pelvic reflections (pouches)
- pararectal fossa
- genitorectal pouch
- vesicogenital pouch
- pubovesical pouch
What is the vaginal process (or vaginal tunic in males)?
A blind ended portion of peritoneum protrudes through the inguinal canal and sits subcutaneously.
• The vag. canal & cavity are continuous with the peritoneal cavity
• The vag. cavity contains nothing except small amount of serous fluid for testicular mobility.
What species is the vaginal process in?
bitches only
not in cat
what does the vaginal process surround in female vs male?
bitch: round ligament of uterus
male: spermatic cord
