Chapter 3 - Digestion

Question 1

What organs are involved in digestion?

Answer 1

mouth
esophagus
stomach
small intestine
large intestine
pancreas
gall bladder

Question 2

mouth

Answer 2

digestive secretions: amylase
breaks down food
salivary glands add saliva to create bolus

Question 3

esophagus

Answer 3

food goes from mouth to stomach thru here

has a sphincter muscle at each end

Question 4

stomach

Answer 4

receives bolus, adds liquid (gastric juices) & churns the food
turns it into chyme
small amounts pass thru pyloric sphincter to small intestine

Question 5

small intestine

Answer 5

3 parts: duodenum, jéjunum, & ileum

Question 6

digestion secretions

Answer 6

salivary glands - amylase
stomach  - gastric juices
pancreas - bicarbonate; pancreatic enzymes
liver (via the gallbladder) - bile
small intestine - intestinal juice

Question 7

crypts

Answer 7

tubular glands that lie between the intestinal villi & secrete intestinal juices into the small intestine

Question 8

digestion secretions of:

salivary glands

Answer 8

saliva

• contains AMYLASE to begin the carbohydrate digestion
• protective role
• moistens food for easy passage

Question 9

digestion secretions of:

stomach

Answer 9

gastric juices

• protein digestion: HCl unfolds proteins so enzymes can get to them
• mucus protects stomach cells

Question 10

digestion secretions of:

pancreas

Answer 10

• bicarbonate neutralizes acidic gastric juices

- pancreatic enzymes break down carbohydrates, fats & proteins

Question 11

digestion secretions of:

liver

Answer 11

• produces BILE which is stored in the gall bladder

Question 12

digestion secretions of:

gall bladder

Answer 12

bile

Question 13

How are nutrients absorbed in the small intestine?

Answer 13

simple diffusion: no energy required
facilitated diffusion: carrier cells transport nutrients from intestine into cell / no energy required
active transport: glucose & amino acids move against their concentration gradient, so require energy

Question 14

anatomy of absorptive system

Answer 14

villi -
microvilli
crypts
goblet cells

Question 15

villi

Answer 15

• regulate nutrient absorption based on needs
• nutrients entering the cells of the villi either go to blood stream (if water soluble or tiny fat fragments) or the lymph (if they are fat soluble)

Question 16

microvilli

Answer 16

• are on villi

- enzymes & “pumps”

Question 17

crypts

Answer 17

• lie between the villi

- tubular glands that secrete intestinal juices into small intestine

Question 18

goblet cells

Answer 18

secrete mucus

Question 19

How are nutrients circulated throughout the body?

Answer 19

1. bloodstream: if water soluble

2. lymphatic system: if fat soluble

Question 20

What is the path each circulation system takes after leaving the digestive tract?

Answer 20

Blood - directly to liver before going to body’s cells

Lymph - enters the blood stream thru subclavian vein, bypassing the liver

Question 21

probiotics

Answer 21

living microorganisms found in foods & dietary supplements that are beneficial to health

Question 22

prebiotics

Answer 22

food components (such as fibers) that are not digested, but are used as food by the GI bacteria to promote their growth & activity

Question 23

Digestive hormones

Answer 23

Gastrin - stomach (stimulates HCl production)
Secretin - small intestine - in response to acid (tells pancreas to secrete bicarbonate-rich juices to increase pH
Cholecystokinin- small intestine - in response to fat (tells gall bladder to secrete bile)

Question 24

Digestive hormones

Answer 24

Gastrin - stomach (stimulates HCl production)
Secretin - small intestine - in response to acid (tells pancreas to secrete bicarbonate-rich juices to increase pH
Cholecystokinin- small intestine - in response to fat (tells gall bladder to secrete bile)