GI system Flashcards
what is the GI system made up of
oral cavity
pharynx
oesophagus
stomach
small interstine
large interstine
rectum
anal canal
what are the GI systems accessory organs
teeth
tongue
salivary glands
pancreas
liver
biliary tree and gallbladder
what germ layers make up the GI tract
endodermal and mesodermal primary germ layers
derives from the primitive gut tube
what is the epithelial lining derived from
embryonic endoderm
what does the epithelial lining give rise to
specific secretory cells (the parenchyma) of the glands
what is derived from the splanchnic mesoderm
connective tissue for glands (stroma)
cognitive tissue, smooth muscle and peritoneal covering of the wall of the tube
what are the divisions of the embryological GI tract
foregut
midgut
hindgut
what does the foregut include
pharyngeal gut tube (pharynx)
where is the foregut
extends from the mouth to the point where the hepatopancreatic ampulla enters the duodenum
where is the midgut
extends from the point where the hepatopancreatic ampulla enters the duodenum to the junction between the proximal 2/3 and the distal 1/3 of the transverse colon
where is the hindgut
extends from the junction between the proximal 2/3 and the distal 1/3 of the transverse colon to the anus
what is the gut tube vascularised by
branches form the abdominal aorta
how is blood supplied to the foregut
by the coeliac trunk
how is blood supplied to the midgut
by the superior mesenteric artery
how is blood supplied to the hindgut
by the inferior mesenteric artery
what is ischaemic colitis
insufficient blood supply to splenic flexure of the colon
where is the he splenic flexure of the colon
the bend where the transverse colon and descending colon meet in the upper left part of your abdomen.
what is the role of the hepatic veins
Drain venous blood from the major parts of the GI tract through the hepatic portal venous system into the vena cava
what is the role of the hepatic portal vein
Receives venous drainage from the abdominal part of the GI tract, pancreas spleen and gallbladder via its tributaries (gastric, splenic and mesenteric veins to the liver
what are the derivative of the foregut
pharynx
larynx
oesophagus
stomach
duodenum (proximal half)
liver
biliary tree and gall bladder
pancreas
what are the derivates of the midgut
duodenum (distal half)
jejunum
ileum
cecum
ascending colon
transverse colon
what are the derivates of the hindgut
transverse colon
descending colon
sigmoid colon
rectum
anal canal
how is a normal physiological umbilical hernia formed
the intestinal loops protrude through the umbilical region of the developing fetus to form Physiological umbilical hernia
where do intestinal loops normally go
normally return back into the abdominal cavity through a number of rotation and fixations of the gut tube
what is omphalocele
failure of the intestinal loops to return back into the abdominal cavity after the physiological herniation
what is eckels (illegal) diverticulum
embryological remnant of the vitelline duct of the yolk sac attached close to the ileocecal junction
what is diverticula of the colon
small out pocketing pouches from the wall of the colon
what can diverticula of the colon lead to
diverticular disease or diverticulitis
what and where is the peritoneum
A smooth thin serous membrane which lines the walls of the abdominal cavity and covers some of the visceral
balloon empty in visceral cavity
what are the 2 layers of the peritoneum
parietal layer
visceral layer
parietal layer of the peritoneum
lines the inner surface of walls of the abdominal cavity
visceral layer
invests or covers most of the abdominal viscera
peritoneal cavity
the potential space between the parietal and visceral peritoneal layers
intraperitoneal
when organs are completely covered by the visceral peritoneum (small intestine)
retroperitoneal
when organs lie behind the peritoneum and are partially covered on their anterior surface only (kidney or pancreas)
what connects one abdominal viscera to another or abdominal wall
fold of peritoneum
mesenteries
mesenteries
double layers of peritoneum
enclose organs and connect them to either the anterior or posterior walls of the abdomen
how do you name mesenteries
named according to the organs / structures they connect
greater omentum
type of mesenteries
a draping double peritoneal fold that connects the stomach to the transverse colon
policeman of the abdominal cavity
lesser omentum
type of mesentery
connects stomach and bit of duodenum to the liver
falciform
type of mesentery
connects the liver to the anterior abdominal wall
what are they 2 ligaments of the lesser omentum
- hepatogastric ligament = connects liver to stomach
- hepatodudenal ligament = connects liver to duodenum
2 peritoneal cavities (sacs)
- omental bursa (lesser sac)
- greater sac
omental bursa / lesser sac
- Omental bursa (lesser sac)
- Perioneal cavity in fold of lesser omentum
- Behind the stomach
- Water bed of which the stomach is lying
- Stomach bed
- Lying anterior to the pancreas and stomach is lying on it
- Part of the bed of the stomach
greater sac
what is remaining of the periotoneal cavity - green and brown = supra colic compartment (green) and infraolic compartment (brown
3 parts of greater sac
supra colic compartment and infracolic compartment