Download BC Science 8 CH02

BC Science 8 CH02
11/5/06
11:39 AM
Page 26
Name
Section
Date
2.2
The Digestive and Excretory Systems
Summary
Textbook pages 64–81
Before You Read
Many structures and organs work together to digest food. What parts of your body do
you think play a role? Write your thoughts on the lines below.
_______________________________________________________________________________________
_______________________________________________________________________________________
◆
✏ Mark the Text
Create an Outline
Make an outline of this
section. Use the headings in
the reading as a starting
point. Include the terms that
you think are important.
✔
●
Reading Check
1. What are the five
nutrients?
What makes up the food you eat?
The food and liquids that you take into your body have
nutrients. Nutrients are substances that supply the energy and
materials your body needs. Your body uses nutrients to grow,
develop, and repair itself. Water is not a nutrient but your
body needs water to transport the nutrients and wastes.
There are five types of nutrients:
◆
Carbohydrates are the body’s quickest source of energy.
Examples: pasta and brown rice
◆
Proteins help to build muscles, skin, hair, and nails.
Examples: fish and nuts
◆
Fats build cell membranes and are stored for energy.
Examples: butter and oil
◆
Vitamins help keep your body healthy and strong.
Examples: vitamin D from sunlight and vitamin C
from oranges
◆
Minerals help keep your body healthy and strong.
Examples: iron from leafy vegetables and calcium
✔
from milk ●
___________________
___________________
___________________
___________________
___________________
How are nutrients from food digested?
The process of digestion breaks down nutrients, absorbs
them, and stores some of them for later use. The digestive
system also removes solid wastes that the body is not able to
use. There are four stages of digestion. Read about them in
the table on the next page.
26
MHR • Section 2.2
The Digestive and Excretory Systems
© 2006 McGraw-Hill Ryerson Limited
BC Science 8 CH02
11/5/06
11:39 AM
Page 27
Section
Name
2.2
Date
Summary
continued
The four
stages of
digestion
What parts
of the
digestive
system are
involved?
What happens?
1. ingesting
mouth
• Food is taken into the mouth.
2. digesting
mouth
esophagus
stomach
small intestine
• Teeth grind food into smaller pieces.
• Saliva mixes with the food pieces.
• Muscles in the esophagus push the food
down into the stomach.
• The food is covered with gastric juice,
which is a mixture of strong hydrochloric
acid, mucus, and enzymes that break down
the food into a liquid form. Enzymes are
proteins that speed up digestion. The thick,
slippery mucus protects the stomach lining
from the strong acid.
• The liquid food leaves the stomach and
enters the first part of the small intestine,
where it is broken down into small nutrient
particles. Tubes connect to other organs,
such as the pancreas, liver, and gall bladder,
that produce substances to help digest the
food.
3. absorbing
small intestine
large intestine
• Nutrients are absorbed in the rest of the
small intestine.
• The small intestine is lined with many villi.
Villi are fold-like structures that increase
the surface available to absorb nutrients.
• Undigested food leaves the small intestine
and enters the large intestine, where water
and some minerals are absorbed.
4. eliminating
rectum
anus
✔
●
Reading Check
2. What are the four stages
of digestion?
• Any undigested material (feces) is stored in
the rectum.
• The feces leave the body through the anus.
___________________
●
✔
How is liquid waste removed from the body?
___________________
___________________
___________________
Excretion is the job of the excretory system. Excretion removes
liquid wastes and gas wastes from the body. Your kidneys filter
liquid wastes from your blood and store the wastes (urine) in
your bladder until they are flushed from the body.
© 2006 McGraw-Hill Ryerson Limited
Section 2.2
The Digestive and Excretory Systems • MHR
27
BC Science 8 CH02
11/5/06
11:39 AM
Page 28
Name
Date
Cloze
Activity
Section 2.2
Use with textbook pages 64–69.
Know your nutrients
Vocabulary
brown rice
butter
calcium
circulatory
digestive
energy
excretory
fish
gastric juice
iron
nuts
oil
pasta
protein
respiratory
villi
vitamin C
vitamin D
Use the terms in the vocabulary box to fill in the blanks. Each term may be used
more than once. You will not need to use every term.
1. Carbohydrates are the body’s fastest source of _________________________________.
2. Examples of foods containing carbohydrates are ________________________________
and ________________________________________________________________________.
3. ________________________________________ help build muscles, skin, hair, and nails.
Examples of foods containing this nutrient are __________________________________
and _______________________________________________________________________.
4. Fats are used to build _______________________________________ and can be stored
by the body for _____________________________________________________________.
5. Examples of foods containing fats are __________________________________________
and _______________________________________________________________________.
6. Two common minerals are ____________________________________________________
and ________________________________________________________________________.
7. Two common vitamins are ____________________________________________________
and ________________________________________________________________________.
8. The ____________________________________________ system breaks down nutrients,
absorbs them, and stores some of them for later use.
9. The ________________________________________ system removes liquid wastes and
gas wastes from the body.
28
MHR • Section 2.2
The Digestive and Excretory Systems
© 2006 McGraw-Hill Ryerson Limited
BC Science 8 CH02
11/5/06
11:39 AM
Page 29
Name
Date
Illustrating
Concepts
Section 2.2
Use with textbook page 70.
Stages of digestion
Use a different colour for each stage of digestion. Colour in the areas of the
digestive system where each of the stages occurs. Be sure to label each section.
© 2006 McGraw-Hill Ryerson Limited
Section 2.2
The Digestive and Excretory Systems • MHR
29
BC Science 8 CH02
11/5/06
11:39 AM
Page 30
Name
Vocabulary
Section 2.2
Date
Use with textbook pages 71–76.
Looking inside digestion and excretion
Match each Term on the left with the best Descriptor on the right.
Each Descriptor may be used only once. You will not need to use all the Descriptors.
Term
Descriptor
1. ______ feces
A. a liquid in the stomach
2. ______ urine
B. fold-like structures that absorb nutrients in the
small intestine
3. ______ villi
C. mixes with food pieces in the mouth
4. ______ gastric juice
D. undigested material leaves the body through this
5. ______ enzymes
E. undigested material stored in the rectum
6. ______ mucus
F. proteins that speed up digestion
7. ______ anus
G. liquid wastes stored in your bladder
8. ______ blood
H. kidneys filter liquid wastes from this
9. ______ saliva
10. ______ nutrients
I. a thick, slippery substance that protects the lining
of the stomach
J. the liquid food that is broken down into nutrients
K. substances that supply energy
30
MHR • Section 2.2
The Digestive and Excretory Systems
© 2006 McGraw-Hill Ryerson Limited
BC Science 8 CH02
11/5/06
11:39 AM
Page 31
Name
Assessment
Section 2.2
Date
Use with textbook pages 64–80.
6. The part of the digestive system in which
nutrients are absorbed includes the
The digestive and
excretory systems
A. stomach and esophagus
B. small intestine and large intestine
C. stomach and small intestine
Circle the letter of the best answer.
1. A nutrient used for quick energy is a
D. all of the above
7. The part of the digestive system that ingests
food is the
A. protein
B. carbohydrate
A. mouth
C. fat
B. stomach
D. mineral
C. esophagus
2. A nutrient used to build cell membranes is a
A. protein
D. all of the above
8. The part of the digestive system that digests
food is the
B. carbohydrate
C. fat
A. mouth and esophagus
D. vitamin
B. stomach
3. A nutrient used to build muscle, skin, hair,
and nails is a
C. small intestine
D. all of the above
A. protein
Match each Term on the left with the best
Descriptor on the right. Each Descriptor may be
used only once.
B. carbohydrate
C. mineral
D. vitamin
4. Iron and calcium are examples of
A. minerals
B. carbohydrates
C. fats
D. vitamins
5. The part of the digestive system in which
undigested material is eliminated includes the
A. rectum and anus
B. pancreas, liver, and gall bladder
C. large intestine
Term
Descriptor
9. ______ digestion
10. ______ excretion
11. ______ gastric
juice
12. ______ mucus
13. ______ nutrients
14. ______ villi
A. thick slippery substance
that protects the stomach
lining
B. breaks down, absorbs, and
stores nutrients
C. liquid in stomach
D. fold-like structures that
absorb nutrients
E. mixes with food pieces in
mouth
F. substances that supply
energy
G. removes wastes
D. none of the above
© 2006 McGraw-Hill Ryerson Limited
Section 2.2
The Digestive and Excretory Systems • MHR
31