Gastric Secretion

Question 1

What is ingestion?

Answer 1

Taking in food

Question 2

What does mechanical digestion involve?

Answer 2

Chewing (mouth)
Churning (stomach)
Segmentation (small intestine)

Question 3

What is propulsion?

Answer 3

Swallowing (oropharynx)

Peristalsis (oesophagus, stomach, small and large intestine)

Question 4

What are the absorption mechanisms?

Answer 4

Lymph vessels

Blood vessels

Question 5

What is defecation

Answer 5

Getting rid of waste out of anus

Question 6

What two sphincters are involved in the stomach?

Answer 6

Cardiac (oesophagus)

Pyloric (duedenum)

Question 7

What are the three layers of muscularis externa?

Answer 7

Longitudinal layer
Circular layer
Oblique layer

Question 8

What curvatures are involved in the stomach?

Answer 8

Lesser curvature

Greater curvature

Question 9

What is the fundus?

Answer 9

Top section of the stomach wall

Question 10

What are the rugae of mucosa?

Answer 10

Ridges inside the stomach

Question 11

What are the layers of the stomach wall?

Answer 11

Mucosa
Submucosa
Muscularis externa
Serosa

Question 12

What do gastric pits do?

Answer 12

Lead to gastric glands

Question 13

What do gastric glands do?

Answer 13

Produce gastric juice

Question 14

What types of cells make up the mucosa of the stomach

Answer 14

Simple columnar epithelium

Question 15

What do mucous neck cells do?

Answer 15

They make up the neck of the gastric pits

Question 16

What are the gastric glands cells?

Answer 16

Parietal
Chief
Mucous neck

Question 17

What cells are at the bottom of the gastric pit?

Answer 17

Enteroendocrine cells

Question 18

Where is most of the gastric juice produced?

Answer 18

Glands in the fundus and body (oxyntic glands)

Question 19

What does gastric juice consist of?

Answer 19

Hydrochloric acid
Pepsinogen
Intrinsic factor
Mucus

Question 20

What do parietal cells do?

Answer 20

Secrets intrinsic factor and HCl

Question 21

What does intrinsic factor do?

Answer 21

Required for absorption of vitamin B12

Question 22

What does HCl do?

Answer 22

Kills microbes
Denatures proteins
Activates enzymes

Question 23

What ph is HCL?

Answer 23

1-3

Question 24

What do chief cells do?

Answer 24

Secretes pepsinogen and gastric lipase

Question 25

What does pepsinogen do?

Answer 25

Breaks down peptide bonds | Converted to pepsin by HCL

Question 26

What does gastric lipase do?

Answer 26

Splits short chain triglycerides into fatty acids and monoglycerides

Question 27

What do mucous cells do?

Answer 27

Secrete mucus

Question 28

What two mucous cells are there?

Answer 28

Superficial epithelia | Mucuous neck cells

Question 29

What does mucus do?

Answer 29

Forms a protective barrier | Has alkaline properties

Question 30

What is gastropathy?

Answer 30

When the stomach goes wrong...

Question 31

What can cause damage to the stomach?

Answer 31

``` Drugs Infection Stress Alcohol Radiotherapy ```

Question 32

What does helicobacter pylori do?

Answer 32

Often leads to ulcers

Question 33

What mechanisms regulate gastric secretion?

Answer 33

Neural and hormonal mechanisms

Question 34

What are the phases of gastric secretion?

Answer 34

Cephalic phase (reflex) Gastric phase Intestinal phase

Question 35

When does the cephalic phase occur?

Answer 35

A few minutes prior to food entry

Question 36

When does the gastric phase happen?

Answer 36

3-4 hours after food enters the stomach

Question 37

When does the intestinal phase happen?

Answer 37

When food enters duodenum | Followed by inhibitory effects

Question 38

What happens in the cephalic phase?

Answer 38

Smell, site, thought and taste of food activates CNS Nerves activated Glands activated Prepares mouth and stomach for food

Question 39

What nerves activate cephalic phase?

Answer 39

Facial Glossopharyngeal Vagus

Question 40

What glands activate during the cephalic phase?

Answer 40

Salivary and gastric

Question 41

What happens in the gastric phase?

Answer 41

Food distended the stomach and stimulates stretch receptors Chemoreceptors detect increase in pH... ...Perisatalisis and gastric juice secretion. Chyme emptied into duodenum pH and distension decreases

Question 42

What is gastric phase an example of?

Answer 42

Negative feedback loop

Question 43

What is gastric phase regulated by?

Answer 43

Gastric

Question 44

Where is gastrin produced?

Answer 44

Released by G cells of gastric glands

Question 45

When is gastrin released?

Answer 45

In response to food in stomach and stimulation of parasympathetic system

Question 46

Gastrin is released into the...

Answer 46

Bloodstream

Question 47

What does gastrin stimulate?

Answer 47

Gastric juice secretion

Question 48

What does gastrin prevent?

Answer 48

Acid reflux

Question 49

When does gastrin production stop?

Answer 49

When pH is less that 2 | Negative feedback

Question 50

When does the intestinal phase occur?

Answer 50

When food enters small intestine

Question 51

What does the intestinal phase inhibit?

Answer 51

Inhibits exit of chyme from stomach by inhibiting gastric motility and contraction of the pyloric sphincter Inhibits gastric secretion

Question 52

What does intestinal phase promote?

Answer 52

Digestion of food in small intestine