The abdominal cavity Flashcards
How does the GI tract form (embryology)?
Blastopore forms GI tract – one end is anus and one end is mouth.
The GI tract is outside the body
What are the regions of the stomach?
- Cardia
- Fundus
- Body
- Antrum
- Pylorus
Has greater and lesser curvature
What is the function of the stomach?
Mechanical digestion via churning. Has oblique muscle in addition to inner circular and outer longitudinal muscles.
Enzymatic digestion using gastric juice (HCl and enzymes).
Forms chyme.
What are the small intestines?
Function: Primary site of absorption of nutrients from food
Consists of three parts: duodenum, jejunum (which has more circular folds – can see on imaging), ileum
What are some differences between the jejunum and ileum?
Jejunum - has longer vasa recta, has less complex vasa recta, has more plicae circulares and folds. No fat in mesentery
Ileum - has shorter vasa recta, more complex arterial arcasdes, less pilcae circulares and folds. Fat in mesentery
What is the large intestines?
Composed of the cecum, colon, rectum, and anal canal
Function: Absorb water, generating faces
Four parts of colon- ascending, transverse, descending, and sigmoid
Cecum- receives the distal ileum
There is the ileocecal junction
What are some features of the large intestines?
Haustra: segmented pouches of the colon. Helps move food slowly
Taeniae coli: longitudinal bands of muscle - helps efficient contraction of circular muscles, helps peristalsis + propelling faces. Helps form haustra
What is the appendix?
Vermiform appendix: blind-ended tube
No longer thought to be vestigial
Function: store gut bacteria, T cells
What is the peritoneum?
The peritoneum is the double-layered sheet of serous tissue lining the abdominal cavity.
The peritoneum attaches some organs to the body wall with special folds called mesenteries.
Mesentery = The mesentery is a fold of membrane that attaches the intestine to the abdominal wall and holds it in place.
What are the different types of organs?
Intraperitoneal: contained within the peritoneum
Retroperitoneal: between the peritoneum and the posterior body wall
Secondarily retroperitoneal: develop in peritoneum and become affixed to the posterior body wall
Which organs are retroperitoneal?
SADPUCKER
S- suprarenal glands A- arota/IVC D- duodenum P- pancreas U- ureters C- colon (ascending and descending) K- kidneys E- e(oesophagus) R- rectum
The ascending and descending colon, duodenum and pancreas are secondary retroperitoneal organs.
What are some intraperitoneal organs?
Stomach, liver, spleen
What are the secondary retroperitoneal organs?
Ascending and descending colon, duodenum and pancreas
What are peritoneal ligaments?
Folds of the peritoneum that are used to connect viscera to viscera or the abdominal wall.
Examples:
- gastrosplenic ligament
- splenorenal ligament
- falciform ligament
- gastrocolic lig
- gastrosplenic lig
- hepatogastric lig
- hepatoduodenal lig
- splenorenal lig
- coronary lig (connects liver and diaphgram)
What is the greater omentum?
Double folded “apron” of peritoneum extending inferiorly from stomach and proximal duodenum to the transverse colon and transverse mesocolon (so from stomach to transverse colon).
Greater omentum can trap infections in the abdominal cavity.
Greater Omentum: a visceral adipose tissue with unique immune functions. Although it is primarily an adipose tissue, the omentum also contains lymphoid aggregates, called milky spots (MSs), that contribute to peritoneal immunity by collecting antigens, particulates, and pathogens from the peritoneal cavity and, depending on the stimuli, promoting a variety of immune responses, including inflammation, tolerance, or even fibrosis.
Omenta are the fused peritoneal folds,
What is the lesser omentum?
The lesser omentum connects the liver and stomach.
The right side is formed by hepatoduodenal ligaments (to do with the portal triad).
Behind this is the epiploic foreman which is a hole that allows communication between greater and lesser sacs.
Free margin of lesser momentum: hepatoduodenal ligament, contains the hepatic artery proper, the common bile duct, the portal vein, lymphatics, and the hepatic plexus of nerves
What are hepatorenal recess/pouch and Subphrenic recess?
Hepatorenal recess or pouch = Potential space where fluid can enter
Subphrenic recess = between liver and diaphragm
What is the Root of the Mesentery?
The origin of the mesentery of the jejunum and ileum from the posterior abdominal wall
What are paracolic gutters?
- Space between lateral abdominal wall and colon
- Pathway for travel of fluids, for example, fluid from a burst appendix can travel upright parabolic gutter into the lesser sac (via epiploic foreman)
What is the rectouterine pouch?
The lowest point in the abdominal cavity while supine.
A common site for collection of pathologies including ascites
What are ascites?
Fluid in peritoneal cavity.
Causes:
- cirrhosis of the liver
- cancer within the abdomen
- congestive heart failure
- tuberculosis
- Starvation
What is the gallbladder?
Function: concentrates and stores bile
Location: under liver in the cystic fossa
What is the spleen?
Function: mechanical filtration of blood cells, generate white blood cells, generate red blood cells (prenatally only)
Location: left upper quadrant, lateral to the stomach
What does the pancreas do?
Exocrine secretion: alkaline pancreatic juice from the acinar cells.
Endocrine secretions: glucagon and insulin from the pancreatic islets
There are two pancreatic ducts-
main and accessory. Pancreatic ducts transmit pancreatic juice, which is created by the exocrine part of the pancreas.
Location: behind the stomach, between duodenum and spleen
