Page 48 - Science Course 2 (Book 1)

Mo2-L3a: How Do Nutrients Enter and Mo2-L3a: How Do Nutrients Enter and Leave the Body?
Leave the Body?

Digestion and Excretion Some foods, like insoluble fiber, that are not digested
leave the body through the rectum.
Organ systems provide movement, transport
substances, and perform many other functions. The rectum of the large intestine stores the solid
waste until the waste is expelled from the body.
Organ systems work together and maintain
homeostasis, or steady internal conditions
when external conditions change. Nutrients are the parts of
food used by the body
Hypo- Homeostasis Hyper- to grow and survive.

Proteins, fats,
carbohydrates,
vitamins, and
minerals are all
nutrients.
The human body breaks down food through the
process of digestion.

Substances that are not used by the body are
removed through the digestive system and by the Calories are a measure of the amount of energy in
excretory system. food.
Calories in Calories out
Food Body Functions
Digestion Beverages Physical Activity

Food enters the digestive system through the mouth.

Mouth

Esophagus

Liver Stomach
Large Small
intestine Intestine
(colon)
Rectum

The esophagus connects the mouth to the
stomach —a flexible baglike organ that contains
enzymes that break down food into smaller parts to
be used by the body. Excretion

The small intestine has two functions—digestion The excretory system removes liquid and gas wastes
and absorption. Nutrients are absorbed by the body from the body. This system includes—
through the small intestine.
• Lungs
The liver makes bile and the pancreas makes • Skin
enzymes, both of which break down food in the • Liver
small intestine. • Kidneys
• Ureter
The large intestine receives solid waste from the • Bladder
small intestine. The large intestine absorbs excess • Urethra
water from the waste material.

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