LESSON 3: A3- Human Digestion

Question 1

TRUE OR FALSE: Humans have a complete digestive system

Answer 1

True

Question 2

The tube our food is digested through is called

Answer 2

the gastrointestinal tract, or GI tract for short

Question 3

What is the GI tracts purpose:

Answer 3

ingest, digest, absorb, and egest our food

Question 4

What digestion occurs in your mouth?

Answer 4

Chemical and physical digestion

Question 5

Physical digestion in mouth

Answer 5

broken down physically by your teeth by tearing and cutting with your incisors and canines and by grinding and crushing with your molars

Question 6

Chemical digestion in mouth

Answer 6

broken down chemically with your saliva which contains enzymes

Question 7

Molars and premolars

Answer 7

Molars: teeth at back

Premolars: infront of molers

-grinding and crushing foods

Question 8

Canines and incisors

Answer 8

Canines: sharp teeth (think dogs)

Incisors: front teeth

-Job is to grab food

Question 9

What is the moist ball of food called?

Answer 9

bolus

Question 10

Function of salivia

Answer 10

Helps digest foods

Question 11

Amylase

Answer 11

• Found in saliva
  Amylase is an enzyme which breaks down complex carbohydrates into smaller disaccharides

Question 12

What function does mucus serve in saliva?

Answer 12

s a protective lubricant which helps you swallow

Question 13

Where is food pushed into after swallowing?

Answer 13

• pushed into the pharynx and your soft palate is raised to prevent food entering your nasal passage

Question 14

What happens at the same time during swalloing

Answer 14

At the same time the epiglottis covers the entrance to your trachea, called the glottis

Question 15

This process of taking food into the body by swallowing is called

Answer 15

ingestion

Question 16

Enzyme

Answer 16

any chemical produced
by cells that facilitates biochemical
reactions in the body, such as
those involved in digestion and
metabolism; all enzymes are
proteins

Question 17

Once food is swallowed, it moves into the stomach through the…

Answer 17

esophagus

Question 18

How does food move through the esophagus

Answer 18

stretched by the food, wave-like muscle contractions called peristalsis push the food downwards

Question 19

The food enters the stomach through a circular piece of muscle called the…

Answer 19

gastroesophageal sphincter

Question 20

peristalsis

Answer 20

the rhythmic, involuntary
wave-like contractions of the smooth

Question 21

When does food enter the stomach?

Answer 21

When the gastrointenal sphincter relaxes, food can enter the J-shaped muscular organ called the stomach

Question 22

What is food mixed with gastric jucies called?

Answer 22

chyme

Question 23

Where does chyme exit from the stomach?

Answer 23

pyloric sphincter

Question 24

TRUE OR FALSE: Lipids and carbohydrates are not digestable in the stomach

Answer 24

TRUE

Question 25

What digestion does your stomach go through?

Answer 25

Chemical and physcial

Question 26

Physcial digestion in stomach:

Answer 26

The muscle in the stomach churns and physically breaks down your food

Question 27

Chemical digestion in stomach

Answer 27

Digestive enzymes, like pepsin which breaks down proteins, chemically digests your food

Question 28

What is the hormone that breaks down food?

Answer 28

Gastrin -makes the stomach release hydrochlorich acid and pepsins to break down food

Question 29

pepsin

Answer 29

a protein-digesting enzyme produced in the stomach

Question 30

4 layers of the stomach

Answer 30

Intermost layer Submucosa Muscular Serosa

Question 31

Intermost layer

Answer 31

- Folded layer called mucosa -Aecretes gastric juices -Epithelial cells divide rapidly

Question 32

Submucosa

Answer 32

-connective tissue -Contains network of nerves

Question 33

Muscularis

Answer 33

-smooth muscle -mscles are constantly churning and mixing food with gastric jucies to produce a semi liquids called chyme

Question 34

Serosa

Answer 34

-smooth -outermost layer -holds stomach in place and secretes lubricating fluid yjay eliminates friction between organs

Question 35

Where does most digestion occur?

Answer 35

Small intestine

Question 36

What does the small intestine digest?

Answer 36

lipids, carbohydrates, and proteins

Question 37

The three sections of the small intestine

Answer 37

-duodenum -jejunum -ileum

Question 38

ileum

Answer 38

where most of the nutrients are absorbed

Question 39

jejunum

Answer 39

where digestion continues and some nutrients are absorbed

Question 40

duodenum

Answer 40

where most enzymes are added

Question 41

The inner surface of the small intestine is folded into many

Answer 41

finger-like projections

Question 42

What are the finger-like projections called?

Answer 42

Villi. -Each villus has capalaeries on it -Each villus is covered with microvili -These increase surface area in small intestine

Question 43

The nutrients enter the bloodstream (i.e. are absorbed) through ...

Answer 43

capillary beds in the villi

Question 44

Types of passive transport

Answer 44

-Osmosis (High to low concentration) -Dialysis (High to low concentration) -Faciliated diffusion (High to low concentration graident but it happens with a carraer protein, which is like a door, allowing easy access to the cell memebrane)

Question 45

Passive transport

Answer 45

Movment of materials across cell memebrane without using ATP

Question 46

Active transport

Answer 46

- Material moved from low concentration to high conentration through a memebrane -protien carrier is used -ATP is used

Question 47

What joins the large intestine and small intestine together?

Answer 47

cecum

Question 48

The colon is the...

Answer 48

longest part of the large intestine

Question 49

What are the 4 parts of the colon?

Answer 49

the ascending, transverse, descending and sigmoid colon

Question 50

What is the last 20cm of the thelarge intestine called?

Answer 50

the rectum

Question 51

the rectum

Answer 51

holds the feces until it can be eliminated, or egested, through the anus

Question 52

Why do humans pass gas?

Answer 52

-it is produced in our intestines and occurs when our intestines cannot digest certain foods

Question 53

Large intestine plays a role in absorption of...

Answer 53

-Water -Ions -Vitamins

Question 54

Our large intestine houses...

Answer 54

Many bacteria -some are helpful bacteria such as e.coli -Bacteria produce vitamins K and B

Question 55

Egestion

Answer 55

the removal of waste food materials from the body -These would include materials like cellulose and fiber (i.e. indigestible materials), which are important as they give us a full feeling for a longer time and reduce overeating

Question 56

How does Egestion work?

Answer 56

-Nerves in the large intestine detect the movement of food in the rectum and tells us to eject the food by a bowel movement

Question 57

Microbes

Answer 57

-Microbes live in our intestins and carry out many different functions

Question 58

End of cecum is

Answer 58

Apendix

Question 59

What does bile do?

Answer 59

Bile turns hydrophobic fats and turns it into fatty acids

Question 60

The beggning of the small intestine is...

Answer 60

duodenum