Digestive System Part 1

Question 1

2 parts of digestion

Answer 1

Physical breakdown (Chewing) and chemical breakdown (Salivary Glands/Hydrolysis)

Question 2

What are the resulting molecules and what do they do?

Answer 2

Monosaccharides, fatty acids, AA etc. diffuse into the bloodstream and then diffuse into the cells

Question 3

Another name for the digestive tract

Answer 3

Gastrointestinal tract (Gut)

Question 4

True or false, food passes through the tract

Answer 4

True

Question 5

How long is the digestive tract?

Answer 5

6.5-9m

Question 6

Another name for chewing

Answer 6

Mastication

Question 7

Chemical breakdown steps

Answer 7

1. Saliva (secreted by salivary glands)
2. Lubricates mouth
3. Dissolves food

Question 8

What is the salivary amylase?

Answer 8

Starch (polysaccharide) digestion into disaccharides
Ex. Maltose

Question 9

What does the food turn into as you swallow?

Answer 9

Bolus

Question 10

What is the trachea covered by?

Answer 10

The epiglottis (flap of tissue)

Question 11

What is the esophagus?

Answer 11

A muscular portion of tract between the mouth and stomach

Question 12

What is the movement in the esophagus?

Answer 12

Muscles contract and relax (peristalsis) moves food down

Question 13

What is the lower esophageal sphincter?

Answer 13

Muscle at the bottom of esophagus relaxes to let food into the stomach.

Question 14

Another name for the lower esophagus sphincter

Answer 14

Cardiac sphincter

Question 15

What happens if the LES is weak?

Answer 15

Acid reflux/heartburn

Question 16

What does the stomach do?

Answer 16

Uses physical digestion (peristalsis) to push food around the stomach

Question 17

What is chyme?

Answer 17

When food is mixed with gastric juice

Question 18

What does mucus in the stomach do?

Answer 18

Prevents damage from stomach acid

Question 19

What is the chemical digestion in the stomach?

Answer 19

1. Gastric juice (contains H2O, mucus, and salts, and pH of 1-3) + (kills bacteria and releases when food is present only)
2. Pepsin (enzyme in stomach that digests proteins, it hydrolyzes proteins to make polypeptides)

Question 20

What is HCl and what does it do?

Answer 20

Hydrochloride acid, it kills most bacteria in the stomach

Question 21

What is the HCl responsible for?

Answer 21

Activating 2 enzymes in the stomach (pepsin and rennin (slows movement of milk through small intestine))

Question 22

What else is HCl responsible for?

Answer 22

Ulcers (mucus lining is destroyed and heliobacter infects exposed area)

Question 23

Is there absorption in the stomach?

Answer 23

Yes, not a lot absorption of nutrients yet, but absorbs water, alcohol, and anti-inflammatory drugs

Question 24

What is at the bottom of the stomach?

Answer 24

Pyloric sphincter

Question 25

What does the pyloric sphincter do?

Answer 25

Relaxes to let food (called chyme) out of the stomach to the small intestine