Chapter 17: Digestive System

Question 1

components of bile

Answer 1

• water
• bile salts
• bile pigments
• cholesterol
• electrolytes

Question 2

bile salts

Answer 2

produced from cholesterol, emulsify fats, only bile component with digestive function

Question 3

gall bladder

Answer 3

• pear shaped
• stores & concentrates bile
• cystic duct from gb joins with common hepatic duct from liver to form common bile duct
• bile duct empties into duodenum
• hematopancreatic sphincter

Question 4

gall stones

Answer 4

• occurs if bile is too concentrated
• crystals

Question 5

cck

Answer 5

causes gall bladder to contract, in response to fats entering the duodenum; the bile is then released into the duodenum

Question 6

what do bile salts do

Answer 6

aid digestive enzymes through emulsification; enhance absorption of fatty acids & cholesterol by forming micelles

Question 7

duodenum

Answer 7

shortest & most fixed end of SI

Question 8

jejunum

Answer 8

middle, thicker & more active than ileum

Question 9

ileum

Answer 9

distal end of SI, Peyer’s patches

Question 10

mesentary

Answer 10

helps to hold ileum & jejunum in place

Question 11

greater omentum

Answer 11

attached to inferior aspect of stomach; hangs down covering intestines

Question 12

intestinal villi

Answer 12

tiny projections of muscles; greatly increase surface area for absorption of digestive end product

Question 13

what does each intestinal villi contain?

Answer 13

simple columnar epithelium w/ a core of connective tissue, w/ BV, lacteal, and nerve fibers

Question 14

microvilli

Answer 14

free surfaces of epithelial cells; increase surface area for absorption

Question 15

Brunner’s glands

Answer 15

specialized mucus secreting cells that secrete a thick, alkaline mucus in response to certain stimuli

Question 16

what do intestinal glands secrete

Answer 16

a watery fluid, that picks up digestion product & transports them to villi; does not have digestive enzymes

Question 17

enzymes in microvilli membranes (4)

Answer 17

• peptidase
• lipase
• sucrase
• maltase

Question 18

carb absorption

Answer 18

• salivary & pancreatic amylase break down starch & glycogen into disaccharides
• intestinal enzymes break down disaccharides to monosaccharides
• monosaccharides absorbed by facilitated diffusion & active transport into BV in villi

Question 19

protein absorption

Answer 19

• pepsin breaks down proteins into polypeptides
• pancreatic proteases break down proteins & polypeptides into smaller proteins
• intestinal peptidases break peptides into AA
• AA absorbed by active transport into BV of villi

Question 20

fat absorption

Answer 20

• emulsified by bile salts
• digested mainly by enzymes from pancreas & SI
• ingested into glycerol and fatty acids
• fatty acids & glycerol absorbed by blood or lacteals

Question 21

peristaltic rush

Answer 21

occurs when small intestine becomes over distended or irritated; sweeps contents into LI, resulting in diarrhea

Question 22

ileocecal sphincter

Answer 22

joins ileum of SI to cecum of LI & helps regulate flow of chyme

Question 23

parts of large intestine (4)

Answer 23

• cecum
• colon
• rectum
• anal canal

Question 24

cecum

Answer 24

• pouch, forms beginning of LI
• appendix is attached here

Question 25

colon

Answer 25

ascending, transverse, descending, & sigmoid

Question 26

rectum

Answer 26

extends from sigmoid to anal canal

Question 27

anal canal

Answer 27

- last 2.5-4 cm of LI; opens to outside as anus - internal & external sphincter guard anus

Question 28

internal sphincter

Answer 28

involuntary

Question 29

external sphincter

Answer 29

voluntary

Question 30

haustra

Answer 30

"bubbles" on LI; bands that create pouches, help form feces

Question 31

taeniae coli

Answer 31

longitudinal muscle that runs down entire length of colon

Question 32

how many layers does the LI wall have?

Answer 32

4

Question 33

what does the LI wall NOT have?

Answer 33

villi & place circulares

Question 34

functions of large intestine (5)

Answer 34

- little to no digestive - contains goblet cells, which secrete mucus - absorbs water & electrolytes - houses intestinal flora, which break down contents such as cellulose, vitamin K & B12, thiamine - forms feces

Question 35

vitamin K

Answer 35

important in blood clotting

Question 36

movements of large intestine

Answer 36

- slower & less frequent than SI - mixing & peristalsis - peristaltic waves produce mass movements, which usually follow a meal - defecation reflex relaxes internal anal sphincter & then external

Question 37

feces composition (4)

Answer 37

- water - mucus - bacteria - bile pigments

Question 38

odor components of feces (5)

Answer 38

- phenol - ammonia - hydrogen sulfide - indole - skatole