ch 11.8- digestive system

Question 1

● Both enzymatic
digestion and
absorption
occur
● Absorbs many
nutrients
(carbs,
proteins, fats,
minerals,
vitamins, water,
& salts

Answer 1

small intestine

Question 2

● Absorption
occurs,
enzymatic
digestion does
not
● Absorption of
vitamins, water,
& salts
● Bacteria
produce
vitamins

Answer 2

Large intestine

Question 3

salivary amylase

Answer 3

saliva breaks down starch into maltose (glucose +
glucose). Saliva also lubricates the food, creating a
bolus.

Question 4

common to digsetive and respiratory systems

Answer 4

pharynx

separates to form trachea and esophogus - epiglottis blocks trachea

Question 5

food enters stomach via

Answer 5

cardiac sphincter

Question 6

what happens in the stomach

Answer 6

mechanical and chemical breakdown of protein and fat occur

Question 7

stomach gastric glands

Answer 7

mucous cells - produce mucous
parietal cells
chief cells
G cells

Question 8

G cells

Answer 8

Food entry causes the stomach to distend, signaling G
cells to release gastrin, a hormone with two
functions:

Question 9

functions of gastin

Answer 9

1. Stimulates parietal cells to release very acidic
   gastric juice (high [HCl]).
2. Stimulates chief cells to secrete gastric lipase
   and pepsinogen. Gastric lipase breaks down
   fats into fatty acids and glycerol. Pepsinogen is a
   zymogen (inactive enzyme precursor) which
   activates into pepsin in acid. Pepsin cleaves
   peptide bonds (proteins → amino acids).

Question 10

chyme enters the small intestine via

Answer 10

the pyloric sphincter

Question 11

small intestine

Answer 11

Responsible for 90% of total digestive absorption.
Consists of three parts: duodenum (digestion),
jejunum, and ileum (absorption).

DJ Eye (i)

Question 12

goblet cells

Answer 12

secrete mucus to protect the epithelial
lining from acidic chyme. Chyme triggers the release of secretin (a hormone), which stimulates the pancreas to release basic bicarbonate ions (HCO3-) into the duodenum via the pancreatic duct.

Question 13

cholecystokinin

Answer 13

CKK

in response to detecting proteins and fats entering
the small intestine, which slows gastric emptying,
stimulates the pancreas to release digestive
enzymes, and tells the gallbladder to release bile
into the duodenum.

Question 14

pancreas

Answer 14

secretes HCO3 - (neutralization),
pancreatic amylase (starch → maltose) and proteases (proteins → amino acids). Trypsin and chymotrypsin are pancreatic proteases, which are initially released as zymogens (trypsinogen and chymotrypsinogen).

Question 15

enteropeptidase

Answer 15

Enteropeptidase in the
duodenum converts trypsinogen to trypsin, which
then converts chymotrypsinogen to chymotrypsin.

Question 16

bile

Answer 16

(emulsifies fats) is produced by the liver and
stored and concentrated by the gallbladder. Bile is
important for the absorption of lipids (fats) from our
diets.

Question 17

ileocecal sphincter

Answer 17

connects the small intestine (ileum) to the large
intestine (colon).

Question 18

vili

Answer 18

(finger-like projections which increase surface
area) are made of enterocytes that are lined with
microvilli. Villi and microvilli increase surface area
and absorption efficiency. Crypts (invaginations in
the intestinal wall) contain cells that secrete enzymes
and produce new epithelial cells for the lining.

Inside the villus, nutrients (glucose and amino acids)
are absorbed into blood capillaries and fats (fatty
acids and glycerol) into lacteals.

Question 19

liver functions

Answer 19

bile production

PUSH DoG

Protein synthesis, Urea synthesis, Storage, Hormone
synthesis, Detoxification, Glucose and fat metabolism
1. Blood maintenance
● Filters and detoxifies blood coming from the
digestive system.
● Detoxifies the body by metabolizing chemicals
and drugs, removing the by-products as waste
via bile → intestines, and kidneys → urine.
● Destroys erythrocytes and bacteria. Kupffer
cells (phagocytes) eat bacteria and get rid of
old RBCs, breaking down their hemoglobin to
bilirubin (yellow) for secretion in the bile.
2. Glucose metabolism
● Glycogenesis: Converts excess glucose into
glycogen for storage in the liver (after meals).
● Glycogenolysis: Breaks down glycogen to
glucose for bodily use (between meals).
● Gluconeogenesis: Converts glycerol and
amino acids into glucose when glycogen stores
are depleted.
3. Protein metabolism
● Synthesizes plasma proteins from amino
acids (albumin and blood clotting factors).
● Converts ammonia (dangerous byproduct of
protein metabolism) into urea (safer) for
excretion.

Question 20

cecum

Answer 20

Water and mineral absorption occur at the cecum
(small pouch). in the large intestine

Question 21

appendix

Answer 21

The appendix (projection in the
cecum) is a vestigial structure with negligible
immune function.

Question 22

colon

Answer 22

water absorption is
completed, hardening feces. The feces is stored in
the rectum and expelled through the anus.

Question 23

bact in large intestine

Answer 23

Many
species of bacteria coexist in the large intestine;
these bacteria serve a critical function in aiding
digestion. Over 99% of bacteria in the large intestine
are obligate anaerobes. These bacteria, as well as all
the other bacteria that are present in or on the body,
are collectively known as a microbiome.

Question 24

large intestine functions

Answer 24

1. Water absorption.
2. Mineral absorption (salts).
3. Vitamin production and absorption: In a
   mutualistic relationship, bacteria produce and
   absorb vitamins, metabolize bile acid, and ferment
   fiber.

Question 25

bile acid metabolism

Answer 25

Bile acid metabolism is a key indicator of the health of
the microbiome. A healthy microbiome will have
sufficient levels of all the bacteria needed for bile acid
metabolism, while an unhealthy microbiome will not,
impairing function.

Question 26

small intestine enzymes

Answer 26

Peptidase- Breakdown of peptides
into amino acids

Maltase, sucrase,
lactase- Breakdown of
disaccharides into
monosaccharides

Enteropeptidase- Activates trypsinogen to
trypsin

Question 27

pancreatic enzymes

Answer 27

Trypsin, chymotrypsin,, carboxypeptidase- Protein breakdown

Pancreatic amylase- Starch breakdown

Nucleases- DNA and RNA
breakdown