It’s your last class before lunch, and you’re starving! Finally, the bell rings and you get to eat!

You feel hungry because your brain receives signals that your cells need energy. But eating is only the beginning of the story. Your body must change a meal into substances you can use. Your digestive system is a group of organs that work together to digest food so that it can be used by the body.

Pharynx

Esophagus

Stomach

Small Intestine

Large Intestine

Anus

Teeth

Salivary Glands

Liver

GallbladderPancreas

Rectum

How Does Food Passes Through Your Body?

Salivary glands pump saliva

while chewing.

The esophagus squeezes the

food smoothly.

The stomach uses chemical and

mechanical digestion

The small intestine absorbs nutrients.

The large intestine is the

last organ of digestion.

The Role of Enzymes in Protein Digestion.

1

2

3

Enzymes act as chemical scissors to cut the long chains of amino acids into small chains.

Enzymes

The small chains are split by other enzymes.

Individual amino acids are small enough to enter the blood streams.

Nutrients are substances that the body needs for normal growth, maintenance, and

repair.

Amino acids are proteins of smaller molecules.

NOTE: Three major types of nutrients-carbohydrates, proteins, and fats-make up most of the food you eat.

Enamel

The function of the liver, gallbladder, and pancreas.

*The liver helps with digestion in the following ways:

-it makes bile to break up fat.

-it stores excess nutrients.

-it breaks down toxins.

*The gallbladder stores the bile made by the liver.

*The pancreatic fluid flows from the pancreas into the small intestine, this fluid contains

bicarbonate, which neutralizes the acid in chyme.

Lengths, widths, and sizes!

The small intestine is a muscular tube that is about 2.5 cm in diameter and if you stretched it, it would be longer that you about 6 m long!If you flattened out the surface of the small intestine , it would be larger than a tennis court! Because the inside wall of the small intestine is covered with fingerlike projections called villi.The liver can as large as a football!The large intestine has a large diameter which is about 7.5 cm and is 1.5 cm long!The human digestive tract can be more than 9 m long!

At The Large Intestine

Undigested material enters the large intestine as a soupy mixture. The large intestine absorbs most of the water in the mixture and changes the liquid into semisolid waste materials called feces, or stool.Fiber keeps the stool soft and keeps material moving through the large intestine.

Which uses which??? :O :/

Chemical mechanical

TeethStomachSmall Intestine

TeethPharynxStomachSmall IntestineLarge Intestine

Mouth & esophagus

Stomach Small Intestine

Large Intestine

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Organs of the digestive tract

*Use the following words in the same sentence:-digestive system-large intestine-small intestine

*Which of the following is not a function of the liver?A. To secrete bile C. to detoxify chemicalsB. To store nutrients D. to compact wastes

*what is the difference between chemical digestion and mechanical digestion?

*put the following steps in order:a. Food is chewed by the teeth in the mouth.b. Water is absorbed by the large intestine.c. Food is reduced to chyme in the stomach.d. Food moves down the esophagus.e. Nutrients are absorbed by the small intestine.f. The pancreas releases enzymes.

*How would the inability to make saliva affect digestion?

Thinking Questions!!!

How do enzymes help in digestions?

What is chyme?

How does eating fiber help in digestion?