Ch14: GI tract

Question 1

digestive tract/GI system

Answer 1

oropharynx, alimentary tract and pancreatic tract

Question 2

oropharynx

Answer 2

mouth
salivary glands
pharynx

Question 3

alimentary tract

Answer 3

esophagus 
stomach
small & large intestine
vermiform appendix
anus

Question 4

pancreatic tract

Answer 4

liver
gallbladder
bile ducts
pancreas

Question 5

digestion

Answer 5

mechanical, chemical and enzymatic processes by which ingested food is converted into simple soluble suitable for assimilation into cells of the body for production of energy and synthesis of tissues

Question 6

esophagus

Answer 6

straight muscular tube that conveys food from the pharynx to stomach

Question 7

stomach

Answer 7

distensible organ whose epithelial components vary in different locations

fundus
antrum
pyloris

Question 8

fundus

Answer 8

body of stomach

mucosal cells secrete HYDROCHLORIC ACID and PROTEOLYTIC ENZYMES which aid in digestion

Question 9

antrum

Answer 9

lower part of stomach
lined by mucous cells that produce thick, basic mucus that protects the epithelial cells from the high acidic content of the gastric juice

Question 10

pylorus

Answer 10

extreme distal end of stomach

muscular sphicter that controls the rate of emptying of the stomach into the small intestine

Question 11

small intestine

Answer 11

major function= absorption
divided into: duodenum, jejunum, ileum
different nutrients are absorbed into different parts
(iron-duodenum, vit B-jej)

Question 12

large intestine

Answer 12

“colon”
storage reservoir for the wastes left over from digestion and also is the main site of water absorption

cecum
ascending colon
transverse colon
descending colon
sigmoid colon
rectum

Question 13

appendix

Answer 13

nonfunctional vestigial structure attached to the cecum

Question 14

anus

Answer 14

muscle sphincter

allows for controlled evacuation of rectal contents at social appropriate times and locations

Question 15

layers of the GI tract

Answer 15

all segments of GI tract are made of the same 4 layers which are continuous with each other:

1: mucosal layer
2: submucosa
3: muscularis propria
4: serosa

Question 16

mucosal layer (mucosa)

Answer 16

3 components:
EPITHELIUM line surface and form glands that are supported by LAMINA PROPRIA (loose CT) and a unique thin muscular layer called MUSCULARIS MUCOSA.
cells varied in accordance with their specialized function at each level of the tract

(esophagus-stratified squamous epithelium for masticated food, stomach-thick glandular mucosa-acid enzymes to break up food, small intestine-villous structures-active absorption, large intestine-mucus secreting cells for storage/evacuation of feces)

Question 17

submucosa

Answer 17

deep to mucosa and provides structural support

contacts lymphatic and vascular channels- pick up absorbed nutrients and carry them to the liver for further processing

Question 18

muscularis propria

Answer 18

contracts rhythmically to move materials through the alimentary tract

Question 19

serosa

Answer 19

thin, smooth membrane present on the outer surface of the alimentary tract that lie within the abdominal cavity
smooth and slippery and keeps the highly tortuous loops of bowel from being tangled up
continuous with the mesentery (CT attachment of the bowel that contains blood vessels, lymphatics and nerves)

Question 20

peristalsis

Answer 20

waves of ms contractions carry a bolus of swallowed food down the esophagus, and a sphincter at the lower end of the esophagus prevents regurgitation

Question 21

amylases

Answer 21

carb-splitting enzymes

from the salivary glads mic with food during mastication

Question 22

trypsins

Answer 22

proteolytic enzymes that digest carbs, fat, and proteins

Question 23

lipases

Answer 23

fat splitting enzymes released by pancreas

Question 24

bile salts

Answer 24

main constitute of bile produced by the liver, emulsify lipids into small water-soluble packets so they can be transported and digested

Question 25

gut microfloral environment

Answer 25

intestinal bacteria serve many important functions:

1: facilitate digestion of certain carbs
2: produce nutrients (folate, vit K)
3: influence development & function of intestinal epithelial cells
4: influence development & responsiveness of GI immune system
5: metabolize certain drugs to active metabolites