Digestive System Lessons 1-2

Question 1

components to digestion

Answer 1

mechanical and chemical

Question 2

what is the mouth bound by

Answer 2

cheeks and lips

Question 3

when does mechanical digestion begin

Answer 3

when the food is chewed(masticated) and shaped into a ball(bolus)

Question 4

what is the tongue responsible for

Answer 4

moving and tasting food inside the mouth

Question 5

what is the tongue composed of

Answer 5

skeletal muscles

Question 6

what is taste? how is it performed?

Answer 6

taste is a type of chemoreception and it is performed by using the taste buds on a tongue

Question 7

how do taste buds work?

Answer 7

taste buds absorb molecules and send signals to the brain to identify the molecule that was sensed

Question 8

what are teeth responsible for

Answer 8

the mechanical breakdown of food

Question 9

what are teeth? how are they used?

Answer 9

teeth are the hardest substances in the human body and are used with jaw muscles to break down food into smaller bits

Question 10

how many baby teeth do children have

Answer 10

20

Question 11

how many teeth would we have after losing our baby teeth

Answer 11

32

Question 12

describe how teeth are stuck to our gums and the components

Answer 12

anchored in the gums by long root extensions, our teeth are layered with enamel, dentin and pulp which house blood vessels in the center

Question 13

the 3 types of teeth

Answer 13

incisors, canines, molars

Question 14

what are incisors usually used for

Answer 14

cutting and plucking(usually plant matter)

Question 15

what are canines usually used for

Answer 15

tearing(usually flesh)

Question 16

what are molars usually used for

Answer 16

crushing and grinding(usually plant matter)

Question 17

what is the roof of the mouth called

Answer 17

the palate

Question 18

what is the function of the palate

Answer 18

it is used to separate two cavities from one another; the nasal cavity and the mouth cavity

Question 19

what is the palate composed of

Answer 19

hard palate and soft palate

Question 20

if a child was born without the full formation of the palate, what would they have?

Answer 20

a cleft palate

Question 21

what are salivary glands

Answer 21

3 paired regions of epithelial tissue that produce saliva

Question 22

what is saliva used for

Answer 22

to assist chemical digestion

Question 23

what is the hard palate composed of

Answer 23

bone

Question 24

what is the soft palate composed of

Answer 24

muscles

Question 25

what is saliva composed of

Answer 25

98% water, along with epithelial cells, white blood cells, antimicrobial agents, electrolytes, mucus and enzymes

Question 26

what is the most important enzyme in saliva

Answer 26

salivary amylase

Question 27

what is the function of salivary amylase

Answer 27

to break down starch into maltose

Question 28

how does salivary amylase break it down

Answer 28

it uses hydrolysis

Question 29

what is the pharynx

Answer 29

the region between the mouth and the esophagus where the digestive and respiratory systems intersect

Question 30

what is the pharynx used for

Answer 30

to act as a gate that allows the appropriate material to pass into the proper tube

Question 31

how does the pharynx function

Answer 31

uses flaps of tissue to close off one system when the other is in use

Question 32

what prevents food from entering the nasal cavity

Answer 32

the uvula and soft palate

Question 33

how do the uvula and soft palate prevent food from entering the nasal cavity

Answer 33

it blocks the nasopharynx

Question 34

what is the entry to the trachea called

Answer 34

the glottis

Question 35

what blocks the glottis to prevent food from going into our trachea(and then into our lungs)

Answer 35

the epiglottis

Question 36

how is food blocked from the glottis?

Answer 36

the trachea rises up to use the epiglottis to block it

Question 37

what is the esophagus

Answer 37

a long and muscular tube

Question 38

what is the function of the esophagus

Answer 38

acts as a pathway for food to travel from the pharynx to the stomach

Question 39

appearance of the esophagus when there is no food

Answer 39

collapsed

Question 40

what is the function of valves in our body

Answer 40

to prevent the risk of backflow when the tubes in our body are empty

Question 41

where does the esophagus terminate/stop

Answer 41

at the lower esophageal sphincter

Question 42

what is a sphincter

Answer 42

a ring-shaped muscle

Question 43

what is the function of a sphincter

Answer 43

capable of contracting in on itself, it seals the space in the center, allowing the regulation of the passage of materials through it

Question 44

when would the lower esophageal sphincter be closed and why

Answer 44

it is closed when food is being digested to prevent the acidic components of the stomach from going back up

Question 45

what is rugae

Answer 45

thick folds in the stomach

Question 46

what is the function of rugae

Answer 46

increases the surface area in the stomach to allow for expansion

Question 47

what are the walls in the stomach composed of and what is their function

Answer 47

smooth muscle, used to assist in mechanical digestion

Question 48

what is in the stomach's lumen

Answer 48

mucous cells

Question 49

what are mucous cells in the stomach used for

Answer 49

to secrete mucous that lines the inner walls to protect the lining from stomach acid

Question 50

how is mechanical digestion performed in the stomach

Answer 50

contraction of the stomach's muscular portion, churning the food and breaking it into smaller portions

Question 51

how is chemical digestion performed in the stomach

Answer 51

by using several important molecules that exist in solution

Question 52

what do the important molecules in the stomach do during chemical digestion

Answer 52

they begin protein digestion

Question 53

what is the acidic fluid responsible for chemical digestion

Answer 53

gastric juice

Question 54

what is gastric juice composed of

Answer 54

HCL, electrolytes, and organic molecules

Question 55

what are the electrolytes present in gastric juice

Answer 55

sodium, potassium, calcium, phosphate, sulfate and bicarbonate

Question 56

what are the organic molecules present in gastric juice

Answer 56

gastrins, pepsins and others

Question 57

what is HCL and what is its function

Answer 57

a strong acid(has a low pH nearing 2), it breaks down the connective tissue in food, kills bacteria and enables the absorption of vitamin B

Question 58

what is pepsinogen and what is its function

Answer 58

a molecule that is converted into pepsin when exposed to HCL and is responsible for converting proteins into smaller polypeptide chains

Question 59

what is gastrin and what is its function

Answer 59

a hormone that begins digestion in the stomach.

Question 60

How is the production and secretion of gastric juice enabled

Answer 60

gastrin is absorbed by the stomach, the transported through the bloodstream to cells lining the stomach. it is secreted by the stomach cells upon sensing the stretching of stomach walls

Question 61

after 2-6 hours in the stomach, describe the food.

Answer 61

it is partially digested with a soupy consistency, and it is called chyme

Question 62

how will chyme leave the stomach

Answer 62

through the bottom of the stomach called the pyloric sphincter

Question 63

what is the pyloric sphincter

Answer 63

a ring-shaped muscle that can contract itself to prevent the passage of materials

Question 64

how does the pyloric sphincter work and why

Answer 64

it opens and closes repeatedly to only allow small amounts of chyme to pass through at a time