Lecture 21 Stomach and Pancreas

Question 1

what is the O/Esophagus and where is it located?

Answer 1

• Tube that connects the pharynx to the stomach

* Posterior to the trachea

Question 2

what epithelium makes up the Oesophagus Mucosa and what is its function?

Answer 2

• Stratified squamous epithelium

* Protection from abrasion

Question 3

what does the Oesophagus Muscularis do?

Answer 3

Modified to propel food down to stomach

Question 4

what kind of shape is the stomach?

Answer 4

J-Shaped organ

Question 5

wheres the Stomach Location?

Answer 5

Base of esophagus

Question 6

whats the Esophageal hiatus?

Answer 6

Esophagus passes through diaphragm

Question 7

what does the Lower esophageal sphincter (LES) do?

Answer 7

prevents reflux

Question 8

whats the 4 main parts of the stomach?

Answer 8

• Cardia
• Fundus
• Body
• Pylorus (pyloric antrum)

Question 9

whats the omentum?

Answer 9

a double layer of peritoneum

connects one organ to another

Question 10

whats the Lesser omentum?

Answer 10

Stomach to liver

Question 11

whats the Greater omentum:?

Answer 11

Stomach to transverse colon

Question 12

what is the Muscularis modified / specialised for?

Answer 12

Motility

Question 13

what are the 3 layers of the Muscularis of the gut tube?

Answer 13

• Oblique (inner)
• Circular (middle)
• Longitudinal (outer)

Question 14

whats Rugae?

Answer 14

Temporary folds that allow for the expansion of the stomach (1.5L)

• Important for storage function

Question 15

Internal Surface of the Stomach

Answer 15

Rugae:

Notice folded core of submucosa with overlying mucosa

Question 16

Modifications of the Gut Tube Gastric Glands

what epithelium makes up the mucosa?

Answer 16

Simple columnar epithelium

Question 17

whats the mucosa of gastric glands?

Answer 17

• In-folding increases surface area for secretion (1.5L/day)

* Glands are permanent!

Question 18

what do Gastric glands need?

Answer 18

• Acid and enzymes for digestion
• Mucous for protection
• Hormones for regulation

Question 19

what are Gastric glands cells?

Answer 19

Parietal cells - secrete acid and intrinsic factor

G cells - Secrete hormones (gastrin)

Chief cells - Secrete pepsinogen (an inactive precursor of pepsin)

Question 20

what do Mucous epithelial cells secrete?

Answer 20

Secrete mucous (protection)

Question 21

whats Chief Cells?

Answer 21

Produce enzymes

Abundant rough endoplasmic reticulum

Apical zymogen granules (contain enzymes)

Basal nucleus

Question 22

whats Parietal Cells?

Answer 22

Produce acid (HCL)

Pump ions (H+)

Abundant mitochondria

Folded structure to increase SA

Question 23

whats Endocrine Control?

Answer 23

• Endocrine cells in mucosa

* Gastrin and Ghrelin secreted into the bloodstream

Question 24

whats Neural control?

Answer 24

• (ENS) - local reflexes (primary control)

* CNS modulates ENS function – long neural reflexes

Question 25

what does the Stomach to Small Intestine need?

Answer 25

Pyloric Sphincter (PS) Controlled release of digested material (chyme) into the small intestine

Question 26

what do parietal cells secrete?

Answer 26

acid and intrinsic factor

Question 27

what do G cells secrete?

Answer 27

hormones (gastrin)

Question 28

what do chief cells secrete?

Answer 28

pepsinogen (inactive precursor of pepsin)

Question 29

Stomach to Small Intestine Acidic chyme enters the SI what does it require?

Answer 29

Further digestion (enzymes) Protection from acidic chyme Mucous Bicarbonate

Question 30

Stomach to Small Intestine what provides mucous thats needed for protection against acidic chyme?

Answer 30

glands in the submucosa of the duodenum.

Question 31

Stomach to Small Intestine what provides enzymes and bicarbonate thats needed for protection against acidic chyme?

Answer 31

Pancreas

Question 32

wheres the pancreas located?

Answer 32

* Head in C-shaped duodenum * Tail to spleen * Posterior to stomach * Duct into duodenal lumen • Retroperitoneal

Question 33

in the pancreas, where does the Bile duct meets pancreatic duct?

Answer 33

at the entrance to the duodenal ampulla

Question 34

in the pancreas, whats the duodenal papilla?

Answer 34

projects into the duodenal lumen

Question 35

in the pancreas, what controls release?

Answer 35

hepatopancreatic sphincter (Sphincter of Oddi)

Question 36

in endocrine what do the pancreatic islet alpha cells secrete? what do the pancreatic islet beta cells secrete?

Answer 36

``` alpha = glucagon beta = insulin ```

Question 37

in exocrine what do acinar cells secrete? what do duct cells secrete?

Answer 37

acinar = digestive enzymes duct = bicarbonate

Question 38

whats the structure of Pancreatic Acinar Cells?

Answer 38

* Apical zymogen granules * Basal nucleus * Abundant rough ER

Question 39

whats the function of Pancreatic Acinar Cells?

Answer 39

Secrete enzymes

Question 40

whats the Pancreatic Acinar Cells similar to?

Answer 40

* Chief cells of Stomach | * Salivary acinar cells

Question 41

What structures allow storage?

Answer 41

sphincters | rugae - distension (folded submucosa)

Question 42

For mechanical digestion you need?

Answer 42

smooth muscle, additional oblique layer in stomach | sphincters

Question 43

What is needed for chemical digestion?

Answer 43

secretion of strong chemicals (acids, enzymes) | protective epithelium