GI A&P

Question 1

function of GI system

Answer 1

–provide nutrients for body with propulsive and mixing movements
–secretion of digestive juices
–absorption of nutrients

Question 2

upper esophageal sphincter

Answer 2

prevents food and fluids from being aspirated into lungs

Question 3

lower esophageal sphincter

Answer 3

–cardiac sphincter
–separates esophagus from stomach
–prevents acidic contents of stomach from entering back into esophagus

Question 4

stomach capacity

Answer 4

1000-1500 mL

Question 5

stomach cells

Answer 5

–lined with columnar epithelium containing millions of gastric glands
–glands contain special cells that secrete HCl, intrinsic factor, and gastrin

Question 6

layers of the stomach

Answer 6

(1) mucosa layer: G-cells, parietal, chief, and epithelial
(2) two muscle layers: propel food from stomach to SI
(3) serosa: outer layer; acts as covering for inner layers

Question 7

G-cells

Answer 7

produce gastrin

Question 8

gastrin

Answer 8

hormone that facilitates production of HCl

Question 9

parietal cells

Answer 9

–produce HCl to help break down food
–produce IF to protect mucosa

Question 10

chief cells

Answer 10

secrete pepsin

Question 11

epithelial cells

Answer 11

secrete bicarb-rich solution to coat and protect mucosa

Question 12

small intestine components

Answer 12

–duodenum
–jejunum
–ileum

Question 13

plicae circulares

Answer 13

circular fold mucous membrane that makes up entire inner wall of small intestines

Question 14

intestinal villi

Answer 14

fingerlike projections situated on plicae circulares

Question 15

microvilli

Answer 15

microscopic projections on each villus

Question 16

crypts of Lieberkuhn

Answer 16

–intestinal glands that secrete about 2L of fluid/day into lumen of intestine
–fluid quickly reabsorbed by villi

Question 17

Goblet cells and Brunner glands

Answer 17

secrete large amounts of mucus to protect small intestine from damage of acidic gastric juices

Question 18

ileocecal sphincter

Answer 18

area where food passes from small into large intestine

Question 19

sphincter of small intestine

Answer 19

–distention of terminal ileum causes relaxation to allow contents to enter large intestine
–distention of cecum prevents reflux back into ileum

Question 20

components of large intestine

Answer 20

–appendix
–ascending colon
–transverse colon
–descending colon
–sigmoid colon
–rectum

Question 21

cells of large intestine

Answer 21

–absorptive cells = absorb water and electrolytes
–goblet cells = produce mucous
–endocrine cells = present and produce hormones, but function is not really understood

Question 22

how does motility work in the GI tract?

Answer 22

due to contraction of 2 layers of smooth muscle (longitudinal and circular)

Question 23

2 types of GI motility

Answer 23

propulsive (peristalsis)
mixing (segmental)

Question 24

what is GI motility regulated by?

Answer 24

enteric nervous system, autonomic nervous system, and hormones

Question 24

function of esophagus

Answer 24

transports food

Question 25

functions of stomach

Answer 25

–stores and churns food
–pepsin digests protein
–HCl activates enzymes, breaks up food, kills germs
–mucus protects stomach wall
–limited absorption

Question 26

functions of small intestines

Answer 26

–completes digestion
–mucus protects gut wall
–absorbs nutrients, most water
–peptidase digests proteins
–sucrases digest sugars
–amylase digests polysaccharides

Question 27

functions of large intestine

Answer 27

–reabsorbs some water and ions
–forms and stores feces

Question 28

function of rectum

Answer 28

stores and expels feces