Monogastric Stomach Motility

Question 1

What contributes to the mechanical breakdown of food particles?

Answer 1

Muscle contractions

Question 2

Gastric contents are released at a controlled rate with the help of what kind of cells?

Answer 2

Specialized smooth muscle pacemaker cells

Question 3

What initiates the contraction of intestinal and gastric muscles?

Answer 3

Ca++

Question 4

When an animal eats a meal, the _____________ expands to accommodate large volumes of food

Answer 4

Fundus

Question 5

This part of the stomach acts like a large mixing chamber

Answer 5

Body (corpus)

Question 6

This part of the stomach acts like a pump

Answer 6

Pyloric antrum

Question 7

Peristaltic contractions get progressively stronger as food moves towards where?

Answer 7

The pylorus

Question 8

What 2 things do peristaltic movements do?

Answer 8

Fragment food into small particles
Influence rate of gastric emptying

Question 9

When the peristaltic contraction reaches the pyloric sphincter it narrows preventing large particles from leaving the stomach and forces them back into the corpus (body). This is called what?

Answer 9

Retropulsion

Question 10

The motility of the stomach is under _______________ control

Answer 10

Neurohumoral control

Question 11

What is neurohumoral control?

Answer 11

Neurotransmitters and hormones affect motility of the stomach and rate of gastric emptying

Question 12

The motility of the stomach _____________ when food enters it

Answer 12

Decreases

Question 13

The motility of the stomach _____________ as food approaches the pyloric region

Answer 13

Increases

Question 14

________________ is released in the pyloric region that increases peristaltic contractions

Answer 14

Acetylcholine

Question 15

The hormonal control of gastric emptying is done by hormone?

Answer 15

Gastrin

Question 16

The rate of gastric emptying is controlled by what 2 things?

Answer 16

Strength of pyloric antral muscle contractions
Degree of contraction of pyloric sphincter

Question 17

What hormones released by the small intestine play a role in the delay of gastric emptying?

Answer 17

Secretin
Cholecystokinin (CCK)
Gastric inhibitory peptide (GIP)

Question 18

Mechanical digestion is essential to what?

Answer 18

Increasing the amount of food surface area

Question 19

What is responsible for chemical digestion?

Answer 19

Digestive enzymes

Question 20

What are the two phases of chemical digestion?

Answer 20

Luminal digestion
Membranous chemical digestion

Question 21

What happens during luminal chemical digestion?

Answer 21

Hydrolysis - large macromolecules are broken down into short chain polymers

Question 22

What happens during membranous chemical digestion?

Answer 22

Hydrolysis is repeated - short chain polymers are completely broken down into their most basic component parts

Question 23

What are the 5 components of a meal?

Answer 23

Carbohydrates
Proteins
Lipids
Vitamins
Minerals

Question 24

What are carbohydrates made up of?

Answer 24

Repeating units of monosaccharides - starches, sugars, cellulose

Question 25

What are proteins made up of?

Answer 25

Repeating units of amino acids

Question 26

A chain of >50 amino acids is a _____________

Answer 26

Protein

Question 27

A chain of <50 amino acids is a ______________

Answer 27

Peptide

Question 28

What are lipids made up of?

Answer 28

Glycerol backbone and 3 fatty acids

Question 29

How are carbohydrates digested?

Answer 29

Begins with amylase in the saliva and continues in the stomach and small intestine

Question 30

How are proteins digested?

Answer 30

Pepsinogen released by chief cells is activated to pepsin by the acidic environment produced by HCl