Stomach

Question 1

Where is the stomach?

Answer 1

between the duodenum and oesophagus

Question 2

Where is the stomach found in the abdominal regions?

Answer 2

epigastric, left hypochondrium

Question 3

What is at the anterior/superior regions of the stomach?

Answer 3

lower ribs/ diaphragm
liver

Question 4

What is at the posterior/inferior regions of the stomach?

Answer 4

diaphragm, spleen, left kidney, adrenal gland, pancreas

Question 5

What does the pyloric sphincter do?

Answer 5

allows food to pass from the stomach to the small intestine -prevents partially digested food and digestive juices from reentering the stomach

Question 6

What condition can affect the pyloric sphincter?

Answer 6

pyloric stenosis which prevents the stomach from emptying into the small intestine

Question 7

What are the rugae?

Answer 7

folds of the organ which can be seen with the naked eye. They help increase surface area and allow for the folding and expansion of the organ.

Question 8

What are the 3 muscles of the stomach

Answer 8

inner circular
outer longitudinal
an extra layer called the innermost oblique.

Question 9

What substances does the stomach absorb and what is this due to?

Answer 9

aspirin and alcohol due to high vascularisation

Question 10

What are the secretory cells of the stomach and what do they secret?

Answer 10

mucous cells - mucus
parietal (oxyntic) cells - HCL and intrinsic factor
chief (zymogenic) cells - pepsinogen, lipase
neuroendocrine cells (G cells) - gastrin, serotonin

Question 11

What is the difference between the neck mucous cells and the surface mucous cells?

Answer 11

neck cells produce mucus that is a little more acidic

Question 12

What is the intrinsic factor required for?

Answer 12

Vitamin B12 absorption in the ileum

Question 13

What happens to pepsinogen?

Answer 13

becomes activated by HCL breaking it down to become pepsin which breaks proteins into smaller amino acids

Question 14

What stimulates the production of HCL by parietal cells?

Answer 14

hormone gastrin released in the bloodstream by endocrine cells stimulates parietal cells to produce HCL

Question 15

Describe parietal (oxyntic) cells in an H&E stain

Answer 15

large round or pyramid-shaped cells, highly acidophilic (very pink), central round nucleus

Question 16

Describe chief (zymogenic) cells in an H&E stain

Answer 16

found in lower regions of the gastric glands, basophilic (very blue)

Question 17

Where is carbonic anhydrase found?

Answer 17

red blood cells, parietal cells in gastric mucosa, pancreatic cells, liver and renal tubules

Question 18

What reaction does carbonic anhydrase catalyse?

Answer 18

catalyses the reaction between water and carbon dioxide to produce carbonic acid (H2CO3), and dissociated products hydrogen and bicarbonate

Question 19

Where are the stomach arteries derived from?

Answer 19

branches of the coeliac trunk

Question 20

How is the stomach held in place?

Answer 20

lesser omentum - extends from the liver to the lesser curvature of the stomach and is also attached to the duodenum
greater omentum - runs from the greater curvature to the transverse colon

Question 21

What is the coeliac trunk and what does it divide into?

Answer 21

The coeliac trunk is a short, wide vessel arising from the anterior aspect of the aorta.
It divides into three branches: the left gastric, the common hepatic and the splenic arteries.

Question 22

What gastric veins drain directly into the portal vein?

Answer 22

the right and left gastric veins.

Question 23

Describe how stomach acid HCL is produced

Answer 23

HCl is produced by the parietal cells of the stomach. To begin with, water (H2O) in the parietal and carbon dioxide (CO2) from blood combine within the parietal cell cytoplasm to produce carbonic acid (H2CO3), which is catalysed by carbonic anhydrase. Carbonic acid then spontaneously dissociates into a hydrogen ion (H+) and a bicarbonate ion (HCO3–).

The hydrogen ion that is formed is transported into the stomach lumen via the H+/K+ ATPase ion pump. This pump uses ATP as an energy source to exchange potassium ions in the parietal cells of the stomach with H+ ions.

The bicarbonate ion is transported out of the cell into the blood via a transporter protein called an anion exchanger which transports the bicarbonate ion out of the cell in exchange for a chloride ion (Cl–). This chloride ion is then transported into the stomach lumen via a chloride channel.

This results in both hydrogen and chloride ions being present within the stomach lumen. Their opposing charges lead to them associating with each other to form hydrochloric acid (HCl).

Question 24

What are the arteries that supply the stomach?

Answer 24

Right gastric artery
Left gastric artery
Short gastric artery
Gastroduodenal artery
Right gastroepiploic (gastroomental) artery
Left gastroepiploic (gastroomental) artery

Question 25

What is anastomosis?

Answer 25

a surgical connection between two structures

Question 26

What is oesophageal varices?

Answer 26

The lower 1/3rd of the oesophagus drains towards the left gastric vein, which in turn goes to the portal vein. In abnormal livers (alcholics, hepatitis), scar tissue builds up (cirrhosis) and blocks the portal vein therefore blood increases in the portal vein. When pressure increases in the liver, this results in collateral circulation developing around the lower oesophagus. These can end up rupturing and can be fatal. Oesophageal varices are abnormally enlarged veins in the oesophagus.

Question 27

What are the types of weight loss surgeries and what are they?

Answer 27

1.Gastric band where a band is tightened around the stomach to decrease its size 2.Gastric bypass (where the top part of your stomach is joined to the small intestine 3.Sleeve gastrectomy where some of the stomach is removed.

Question 28

Describe gastric bypass

Answer 28

the top part of the stomach is joined to the small intestine, decreasing the size of the stomach the duodenum is reconnected as the bile from the liver and the pancreatic enzymes are still needed for digestion.

Question 29

What are the main regions of the stomach?

Answer 29

cardia, fundus, body, pylorus

Question 30

What are the divisions of the pylorus?

Answer 30

pyloric antrum, pyloric canal, pyloric sphincter

Question 31

What are the borders of the stomach called?

Answer 31

greater, and lesser curvatures

Question 32

What is the greater omentum and what is it's function?

Answer 32

Attached to the greater curvature of the stomach and transverse colon. Made from 2 layers of peritoneum. Made from adipose tissue, lymphatics, blood vessels and nerves. The function is fat storage and infection encasing.

Question 33

What is the lesser omentum and what is its function?

Answer 33

Attached from the lesser curvature to the liver. Also made from 2 layers of peritoneum. adipose tissue, lymphatics, blood vessels and nerves. The function is to attach stomach and duodenum to liver

Question 34

Where does the arterial supply of the stomach come from?

Answer 34

coeliac trunk

Question 35

What parasympathetic nerve innervates the stomach?

Answer 35

vagus 10

Question 36

What is the semi-liquid substance composed of digested food and gastric juices called?

Answer 36

chyme

Question 37

What is the epithelial lining of the stomach?

Answer 37

simple columnar epithelium with mucus protective layer with gastric pits that delve into gastric glands

Question 38

What veins drain into the splenic vein then into the superior mesenteric vein?

Answer 38

short-gastric and left gastroepiploic (gastroomental) veins

Question 39

What vein drains directly into the superior mesenteric vein?

Answer 39

right gastroepiploic (gastroomental) vein

Question 40

Why is mucous important in the stomach?

Answer 40

provides alkaline to combat the strongly acidic environment that can cause ulcers if not neutralised

Question 41

How is gastrin produced?

Answer 41

innervation of the parasympathetic vagus nerve results in acetylcholine, acting on receptors on parietal cells. The hormone gastrin is produced by endocrine cells in the pyloric antrum in response to rising gastric pH

Question 42

What are the sympathetic nerves of the stomach?

Answer 42

T6-T9