Respiration and Excretion - The Respiratory System
1. Complete unit planner by writing activities and
homework in the appropriate places.
2. Read the paragraph on page 564.
3. Write the answer to the following question as
Why do astronauts wear
space suits and carry oxygen with them when they
walk outside a spacecraft?
today’s bellringer:
Respiration and Excretion - The Respiratory System
Respiratory System Functions
Two important truths about the air you breathe…
1. The oxygen your body needs comes from
the atmosphere – the blanket of gases that
surrounds the earth.
2. When you exhale, most of the air goes back
into the atmosphere.
Respiration and Excretion - The Respiratory System
Respiratory System Functions
1. The respiratory moves oxygen from the
outside environment into the body.
2. The respiratory also removes carbon
dioxide and water from the body.
Respiration and Excretion - The Respiratory System
Respiratory System Functions
Oxygen from the air and glucose from
digested food are both carried to the cells by
the blood. During respiration, oxygen reacts
with glucose to release energy.
Respiration and Excretion - The Respiratory System
Respiratory System Functions
So what is needed for the
energy-releasing chemical
reactions that take place inside
your cells?
Respiration and Excretion - The Respiratory System
So what is respiration?
Respiration is the process in
which oxygen and glucose
undergo series of chemical
reactions inside cells to release
energy.
In addition to energy, carbon
dioxide and water are also
products of respiration.
Respiration and Excretion - The Respiratory System
A Little Review
Respiratory System
Digestive System
Circulatory System
Respiration and Excretion - The Respiratory System
The Path of Air
Respiration and Excretion - The Respiratory System
Your Nose
Respiration and Excretion - The Respiratory System
Your Nose
Air enters the body through openings in the
nose called nostrils and then moves into
spaces called the nasal cavities which are
lined with cilia and mucus.
Cilia are tiny hairlike extensions that sweep
mucus into the throat.
Mucus moistens the air and traps particles in
the air.
Respiration and Excretion - The Respiratory System
The Path of Air
Respiration and Excretion - The Respiratory System
Your Throat
Another name for the pharynx…
The pharynx is shared by both the respiratory
system and the digestive system.
Both the nose and the mouth connect to the
pharynx.
Respiration and Excretion - The Respiratory System
The Path of Air
Respiration and Excretion - The Respiratory System
Your Windpipe
Another name for the trachea…
The trachea feels like a tube with a series of
ridges. These ridges are made up of rings of
cartilage that strengthen the trachea and keep
it open.
Respiration and Excretion - The Respiratory System
The Path of Air
Respiration and Excretion - The Respiratory System
The Path of Air
Respiration and Excretion - The Respiratory System
Gas Exchange
After air enters an alveolus, oxygen passes
through the wall of the alveolus and then
through the capillary wall into the blood.
Carbon dioxide and water pass from the blood
into the alveoli.
Respiration and Excretion - The Respiratory System
How You Breathe
When you breathe, the actions
of your rib muscles and
diaphragm expand or contract
your chest. As a result, air
flows in or out.
Respiration and Excretion - The Respiratory System
Breathing and Speaking
Two vocal cords, folds of
connective tissue that produce
your voice, stretch across the
opening of the larynx. Air
moving over the vocal cords
causes them to vibrate and
produce sound.
Respiration and Excretion - The Respiratory System
Sequencing
As you read, make a flowchart that shows the path of air in
the respiratory system. Write each step of the process in a
separate box in the order in which it occurs.
Path of Air
Air enters the nose.
To the pharynx
To the trachea
To the bronchi
To the lungs
To the alveoli
Respiration and Excretion
End of today’s notes.
Respiration and Excretion - The Respiratory System
Surface Area
Surface area refers to the total area of all the surfaces of a
three-dimensional object. Consider a cube, which has six
equal sides. Each side measures 2 cm by 2 cm.
1. To find the surface area of the cube, first calculate the area
of one of the six sides:
Area = length X width = 2 cm X 2 cm = 4 cm2
Each side has an area of 4 cm2.
2. Then, add the areas of the six sides together:
4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 =
24 cm2
The surface area of the cube is 24 cm2.
Respiration and Excretion - The Respiratory System
Surface Area
Practice Problem
Calculate the surface area of a cube whose side
measures 3 cm.
54 cm2
Respiration and Excretion - The Respiratory System
Breathing Process Activity
Click the Active Art button to open a browser window and
access Active Art about the breathing process.
Respiration and Excretion - The Respiratory System
The Air You Breathe
The air you breathe in contains
several different gases, shown in
the circle graph on the left. The
air you breathe out contains the
same gases, but in the amounts
shown in the circle graph on the
right.
Respiration and Excretion - The Respiratory System
The Air You Breathe
Reading Graphs:
What does each wedge of the
graphs represent?
Percent of a gas breathed in
or out
Respiration and Excretion - The Respiratory System
The Air You Breathe
Interpreting Data:
Based on the data, which gas
is used by the body? Explain.
Oxygen; less oxygen is
breathed out than breathed
in—meaning that some must
have been used by the body.
Respiration and Excretion - The Respiratory System
The Air You Breathe
Drawing Conclusions:
Compare the percentage of
carbon dioxide in inhaled air
with the percentage in
exhaled air. How can you
account for the difference?
There is a higher percentage
of carbon dioxide in exhaled
air. Carbon dioxide is a waste
product of cellular activity.
Respiration and Excretion - The Respiratory System
The Air You Breathe
Inferring:
Explain why the percentage
of nitrogen is the same in
both inhaled air and exhaled
air.
Nitrogen is not used by the
body and is not a waste
product.
Respiration and Excretion
End of Section:
The Respiratory
System