Gastrointestinal system 2

Question 1

Describe the stomach

Answer 1

J-shaped organ at the base of the esophagus

Question 2

What are the parts of the stomach (top to bottom)

Answer 2

Cardia
Fundus
Body
Pylorus

Question 3

What connects the stomach to other organs

Answer 3

Lesser omentum - connects to liver

Greater omentum - connects to transverse colon

Question 4

What are the three modified layers of the muscularis

Answer 4

Oblique
Circular
Longitudinal

Question 5

Describe the internal surface of the stomach

Answer 5

Rugae - temporary folds allow for expansion (1.5L) - storage

Question 6

Describe rugae

Answer 6

Folded core of submucosa with overlying mucosa

Question 7

Describe the mucosa in the stomach

Answer 7

Simple columnar epithelium

In folding to increase surface area for secretion (3L) - permanent glands.

Question 8

What is needed in the stomach

Answer 8

Acid and enzymes (digestion)
Mucous (protection)
Hormones (regulation)

Question 9

What cells make up a gastric gland

Answer 9

Parietal cells
G cells
Chief cells
(mucous cells - surface)

Question 10

What do parietal cells secrete

Answer 10

Acid and intrinsic factor (Vit B12 absorption)

Question 11

What do G cells secrete

Answer 11

Hormones - gastrin (regulate secretion and motility)

Question 12

What do chief cells secrete

Answer 12

Enzymes - Pepsinogen - inactive precursor of pepsin (digests proteins)

Question 13

Describe the structure of chief cells

Answer 13

Abundant RER
Apical zymogen granules - containing enzymes
Basal nucleus (due to granules)

Question 14

Describe the structure of parietal cells

Answer 14

Central nucleus
Folded structure to increase surface area for ion pumps (H+)
Abundant mitochondria to pump H+ against conc. gradient

Question 15

Describe the endocrine control in the stomach

Answer 15

Endocrine cells in mucosa

Gastrin and Ghrelin secreted into bloodstream

Question 16

Describe neural control in the stomach

Answer 16

Enteric nervous system (ENS) - local reflexes

CNS modulates ENS function - long neural reflexes

Question 17

What is chyme

Answer 17

Partially digested food material - acidic

Question 18

What is the function of the pyloric sphincter (PS)

Answer 18

To control the release of chyme into the small intestine

Question 19

What needs to be done to chyme when entering the small intestine

Answer 19

Further digestion (enzynmes produced by pancreas) 
Protection from acidity - Mucous - neutralize acid (bicarbonate)

Question 20

Describe the pancreas

Answer 20

Head in C -shaped duodenum
Tail to spleen 
Posterior to stomach 
Duct in duodenal lumen 
Retroperitoneal (doesn't move)

Question 21

How does the pancreas secrete things

Answer 21

Bile duct meets pancreatic duct at entrance to hepatopancreatic ampulla
Duodenal papilla projects into duodenal lumin
Release controlled by hepatopanreatic sphincter

Question 22

What are the endocrine functions of the pancreas

Answer 22

Pancreatic islet alpha cells - glucose

Pancreatic islet beta cells - insulin

Question 23

What are the exocrine functions of the pancreas

Answer 23

Acinar cells - digestive enzymes

Duct cells - bicarbonate

Question 24

Describe acinar cells

Answer 24

Secrete enzymes 
Apical zymogen granules 
Basal nucleus
Abundant RER 
(like chief cells in stomach)