Gastrointestinal System (Functions)

Question 1

Digestion

Answer 1

breaking down of larger food particles into molecules small enough to enter the body cells

Question 2

ingestion

Answer 2

taking foods and liquids into the mouth

Question 3

secretion

Answer 3

water, acid, buffers and enzymes secreted into the lumen

Question 4

lumen

Answer 4

interior space

Question 5

mixing and propulsion

Answer 5

alternating contractions and relaxations of smooth muscle mixes food

Question 6

mechanical digestion

Answer 6

chewing/grinding food (mastication)
churning of food in the stomach and small intestine
consists of various movements that aid in chemical digestion; food must be pulverized by teeth

Question 7

chemical digestion

Answer 7

enzymes break down food into smaller molecules
series of catbolic reactions that break down the large carbohydrate, lipd, and protein molecules that we eat, into smaller molecules usable by body cells

Question 8

absorption

Answer 8

entrance of ingesed materials into epithelial cells that line the lumen of the GI tract

Question 9

defecation

Answer 9

waste leaves the body; feces

Question 10

teeth

Answer 10

cut, tear, and pulverize food

reduce to smaller particles for swallowing

Question 11

extrinsic muscle (tongue)

Answer 11

move tongue from side to side and in and out

food (bolus) maneuvered for mastication and swallowing

Question 12

intrinsic muscle (tongue)

Answer 12

alter shape of the tongue

swallowing and speech

Question 13

taste buds

Answer 13

receptors for food stimulus

Question 14

glands

Answer 14

secrete lingual lipase

breaks down triglycerides into fatty acids

Question 15

major salivary glands (parotid, submandiable, sublingual

Answer 15

secrete saliva in the lining of the mouth and pharynx
softens moistens and dissolves food
cleanses mouth and teeth
saliva amylase splits polysaccharides into smaller particles

Question 16

pharynx

Answer 16

pharngeal stage of swallowing (deglutition)
moves bolus from oropharynx to laryngopharynx and into the esophagus
closes air passage ways

Question 17

esophagus

Answer 17

esophageal stage of swallowing: forces bolus down the esophagus
relaxation of upper and lower esophageal sphincter: permits entry of bolus from laryngopharynx into esophagus and eventually into the stomach
secretion of mucus lubricates esophagus for smooth passage of bolus

Question 18

stomach

Answer 18

the primary digestive organ

Question 19

mucosa

Answer 19

chief cells: secretes pepsinongen (breaks peptide bonds in protein
secretes gastric lipase (splits short chain triglycerides into fatty acids and monoglycerides

Question 20

parietal cells

Answer 20

secretes hydrochloric acid (kills microbes in food, modifies the molecular structure of protein, inhibits secretion of gastrin)
secretes intrinsic factor (needed for absorption of vitamin B12

Question 21

muscosa surface cells

Answer 21

secretes mucous (forms a protective barrier that prevents digestion of the stomach wall)

Question 22

enteroendocrine cells

Answer 22

secretes gastrine (stimulates paretal cells to secrete HCL and chief cells to secrete pepsinogen, contracts lower esphageal sphincter, increase motility of the stomach, relaxes pyloric sphincter)

Question 23

muscularis

Answer 23

mixing waves (masecerate food and mix with gastric juices to form chyme) 
peristalisis (froces chyme through pyloric sphincter)

Question 24

pyloric sphincter

Answer 24

opens to permit passage of chyme to duodenum

Question 25

pancreas

Answer 25

secondary organ aiding chemical digestion in the small intestine

Question 26

pancreatic juice

Answer 26

buffers acidic gastric juices into chyme stops the action of pepsin from the stomach creates the proper pH balance for action of digestive enzymes in the small intestine

Question 27

liver

Answer 27

heaviest gland in the body | second organ aiding in chemical digestion

Question 28

liver (functions)

Answer 28

``` carbohydrate metabolism - maintains normal blood glucose level lipid metabolism protein metabolism removal of drugs and hormones exretion of bilirubin strorage of some vitamins and minerals avtivation of vitamin D ```

Question 29

gallbladder

Answer 29

secondary organ aiding chemical digestion | store and concentrate bile

Question 30

small intestine

Answer 30

major site of digestion and absorption

Question 31

intestinal glands

Answer 31

secrete intestinal juices

Question 32

duodeneal gland

Answer 32

secrete alkaline fluid to buffer stomach acids and mucous for protection and lubrication

Question 33

microvilli

Answer 33

microscopic membrane covered projections of epithelial cells increase surface are for absorption and digestion

Question 34

villi

Answer 34

finger-like projections sites for digestion of food increase the surface area for digestion and absorption

Question 35

circular folds

Answer 35

folds of the mucosa and submucosa that increase surface area for absorption and digestion

Question 36

muscularis segmentation

Answer 36

alternationg contractions of circular fibers that produce segmentation/resegmentation of the small intestine mixes chyme with digestive juices

Question 37

chyme

Answer 37

semifluid mixture of parly digestive food and digestive secretions found in the stomach and small instestine during digestion of a meal

Question 38

peristalsis

Answer 38

mild waves of contractions and relaxation of circular and longitudinal muscles moves chyme foward through the samll intestine and towards the ileocecal sphincter

Question 39

mucosa (large intestine)

Answer 39

secretes muscus to lubricate colon and protec mucosa absorbs water and other soluble compounds to maintain water balance solidifies feces absorbs vitamins and some ions

Question 40

lumen (large intestine)

Answer 40

bacterial activiy helps break down undigestied carbohydrates, proteins and amino acids into products that can be expelled in feces or absorbed synthesizes certain B vitamins and vitamin K

Question 41

muscularis (large intestine)

Answer 41

moves contents from the haustra to hasutra (pouch) by musular contraction moves contents along length of the colon by contractions of cucular and longitudinal muscles mass peristalsis forces contents into the sigmoid colon and rectum defecation reflex eliminates feces by contractions in sigmoid colon and rectum