1primary functions of the digestive system
digest food, excrete waste
2processes involved in digestion
ingestion, motility, secretion, digestion, absorption, elimination
3swallowing is the _________ interaction we have with our food.
last
5what is the oral cavity?
the mouth
6what does the oral cavity consist of?
saliva, teeth, tongue
7what enzyme does saliva contain?
amylase
8what does amylase do?
initiates chemical digestion, begins breaking down carbs in food
9bolus
saliva mixed with food
10what structure functions in mastication?
teeth
11where is the pterygold located?
in the masseter
12what does the pterygold muscle do?
moves jaw side to side
13what muscles function in mastication?
pterygold, temporalis, tongue
14carbohydrates are just many __________ linked together
sugars
15what is deglutition?
swallowing
16route of food
oral cavity - oropharynx - laryngopharynx - esophagus - stomach
17what is glycogen?
stored energy from carbohydrates that were not used
18chyme
bolus + gastric juices
19which structure is primarily responsible for chemical digestion?
stomach
20the stomach acts as a ___________ ______ for food.
holding sac
213 cells of the gastric gland
surface mucosa, mucous neck, chief cells, parietal cells
22what cell produces pepsinogen?
chief cells
23pepsinogen is activated by -
an acidic environment (low pH)
24pepsinogen is converted to _________ in an acidic environment.
pepsin
25pepsin is a ___________.
protease
26function of pepsin
catabolizes peptide bonds (proteins)
27what do parietal cells produce?
HCl
28what does HCl in the stomach do?
creates acidity for pepsinogen to be converted to pepsin
29function of pyloric sphincter
traps food in stomach, only relaxes to let small amount through to the small intestine as we eat more or less
30function of liver
formation and release of bile for emulsification of lipids (fats)
31lipases digest ________
lipids (fats)
32protease digests __________
proteins
33fat and water DO NOT mix in the small intestine because it is an ___________ environment.
aqueous
34function of large intestine
absorb water; prepares cookie
35function of small intestine
absorbs nutrients
36what is peritoneum?
serous membranes lining the abdominal cavity and organs
37parietal peritoneum
lines abdominal cavity
38visceral peritoneum
lines organs
39function of peristalsis
to move remaining undigested material and bacteria toward the large intestine
40function of stomach
chemical digestion
41what are the cells of the stomach?
surface mucous cells, mucous neck cells, parietal cells, chief cells, G-cells
42what do G-cells do?
instruct the muscles of the stomach to churn
43function of muscle tissue in stomach
to churn ingested food
44what is the exocrine function of the pancreas?
produce digestive enzymes
45amylase digests _________________.
carbohydrates
46what is an ulcer?
a sore that occurs on the lining of the esophagus, stomach, or small intestine
47when does an ulcer occur?
when acid has damaged the lining of the digestive tract
48function of gallbladder
stimulates the release of bile
49pancreatitis
when pancreatic enzymes digest the pancreas
50function of circular folds in the small intestine
act as "speed bumps"; slows down the movement of chyme to ensure nutrient absorption
51function of brush border enzymes
makes nutrients absorbable by breaking them down
52function of colon
longest part of the large intestine; passes digested food to rectum
533 pairs of salivary glands
parotid, submandibular, sublingual
54the parotid gland secretes ___________% of saliva
25-30
55the sublingual gland secretes ___________% of saliva
3-5
56the submandibular gland secretes ___________% of saliva
60-70
57structure of teeth
crown, neck, root
58structures in swallowing
oral cavity, pharynx, salivary glands, esophagus
59function of lacteals
absorption of fats from the small intestine
60composition of feces
75% water and 25% solids
61Why must fats be emulsified?
to increase the surface area of them so they can be broken down