stomach Flashcards
describe the abdomen
- very large
- extends under the rib cage
- body cavity between diaphragm and pelvic inlet
- separated from thorax but not from pelvis
- supported partly by the pelvis
what tissue is the abdomen made of?
adipose tissue
multi-layered musculoaponeurotic wall
what are the 9 divided regions of the abdomen?
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1- right hypochondrium
2- epigastric
3- left hypochondrium
4- right lumbar
5- umbilical
6- left lumbar
7- right iliac fossa
8- suprapubic (hypogastrium)
9- left iliac fossa
what are the vertical lines of the abdomen divisions called?
mid-clavicular lines
what is the upper horizontal line in the abdomen division called?
the subcostal line
what is the lower horizontal line in the abdomen division called?
intertubecular line
what region of the abdomen is the liver found?
1
what region of the abdomen is the duodenum, liver, gallbladder, pancreas and stomach found?
2
what region of the abdomen is the spleen and stomach found?
3
what region of the abdomen is the ascending colon and kidney found?
4
what region of the abdomen is the stomach, head of pancreas, duodenum, transverse colon and kidneys found?
5
what region of the abdomen are the descending colon and left kidney found?
6
what region of the abdomen are the caecum , appendix and ascending colon found?
7
what region of the abdomen are the bladder, uterus, ilium found?
8
what region of the abdomen are the sigmoid colon, descending colon found?
9
where is the stomach found?
the left hypochondrium/ epigastric region (1/2)
what is found anterior/superior to the stomach?
lower ribs, diaphragm and liver
what is found posterior/inferior to the stomach?
diaphragm, spleen, left kidney, adrenal gland and pancreas
what attaches to the greater curvature of the stomach?
the greater omentum (fatty tissue)
what can affect the pyloric sphincter?
the pyloric stenosis
what can affect the pyloric sphincter?
the pyloric stenosis
what are the regions of the stomach?
cardiac sphincter
fundus
body
pylorus
pyloric sphincter
what is the stomach responsible for?
the breakdown of ingested material by enzymes and hydrochloric acid
what are rugae?
folds of the organ which can be seen with the naked eye- help increase surface area and allow for the folding of the organ
how many layers of muscle are there in the stomach wall and what are they for?
3- help with the churning, or mixing, of the stomach contents called the chyme: usual inner circular and outer longitudinal, but also an extra layer called the innermost oblique.
what are the functions of the stomach?
- Stores swallowed food
- “Retention” of food
- Mixing of gastric “juice”
- Chemical and mechanical functions
- Limited absorption – except alcohol and aspirin
where does most absorption of the GIT take place?
the small intestine
what are the secretory cells in the stomach?
Mucus secreting cells (mucous neck cells and surface mucous cells- both produce mucous yet the neck are slightly less alkaline)
– luminal surface and gastric pits
- alkaline
Parietal (oxyntic) cells
– HCl and intrinsic factor
- intrinsic factor required for vitamin B12 absorption in ilium
- vitamin B12 is needed for normal nervous sytem function and maturation of rbcs in bone marrow
Chief (zymogenic) cells
– produce pepsinogen which is activated to become pepsin under the production of acid. That pepsin then breaks down proteins into smaller amino acids
Endocrine cells
- secrete gastrin into bloodstream which then stimulates the production of hydrochloric acid by the parietal cells, which breaks down pepsinogen to pepsin
what protects the mucosa?
mucous and surface mucous cells
describe parietal cells
large round or pyramid shaped cells, stain pink i.e. highly acidophilic, central round nucleus
describe chief cells
found in lower regions of the gastric glands, basophilic (very blue)
what does carbonic anhydrase do?
catalyses the reaction between water and carbon dioxide to produce carbonic acid (H2CO3), and dissociated products hydrogen and bicarbonate
where are the arteries of the stomach derived from?
branches of the coeliac trunk
what is the coeliac trunk?
a short, wide vessel arising from the anterior aspect of the aorta just below the diaphragm. It divides into three branches
which is the smallest branched artery of the coeliac trunk?
the left gastric artery- branches include to the lower oesophagus, cardia and lesser curvature of the stomach
which artery gives rise to the right gastric and gastroduodenal arteries?
the heptic artery
what are the three branches of the coeliac trunk?
the left gastric, the common hepatic and the splenic arteries
what is the largest branch of the coeliac trunk?
splenic artery -it runs a tortuous course to the left along the superior border of the pancreas, initially behind the omental bursa and then within the splenorenal ligament, and terminates near the hilum of the spleen. It provides collateral branches to the pancreas and terminal branches to the spleen and stomach.
where do the veins of the stomach drain?
into the portal venous system
what veins does the portal vein receive?
superior and inferior mesenteric veins, the splenic vein, gastric vein, and cystic vein
what veins does the splenic vein receive?
the short gastric and left gastro-omental (gastroepiploic) veins
what veins does the superior mesenteric vein receive?
right gastro-omental
what are oesophageal varices?
- Oesophageal veins ->azygos vein ->superior vena cava
- Portal pressure > inferior vena cava pressure
- Increased portal pressure (portal hypertension)
- Collateral circulation around stomach, oesophagus and rectum
- rupturing- fatal
where is the upper 2/3rds of oesophagus drained?
via oesophageal veins carrying deoxygenated blood to the azygos vein, and then onto the superior vena cava. These veins are not involved in oesophageal varices.
where does the lower 1/3rd of the oesophagus drain?
drains towards the left gastric vein, which in turn goes to the portal vein
describe gastric band surgery
This falls into the category for weight loss surgery, and there are several types of weight loss surgery:
Gastric band
Gastric bypass (where the top part of your stomach is joined to the small intestine- duodenum reconnected as the bile from the liver and pancreatic enzymes are still needed for digestion)
Sleeve gastrectomy where some of the stomach is removed.
These operations are only considered if their Body Mass Index over 40 or 35-40 if the patient has an obesity related condition eg type 2 diabetes, or hypertension,
