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
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
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
The Path of Air
As air travels from the
outside environment
to the lungs, it passes
through the following
structures: nose,
pharynx, trachea, and
bronchi.
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 - Smoking and Your Health
Health Problems and Smoking
Over time, smokers can develop chronic bronchitis,
emphysema, lung cancer, and atherosclerosis.
Respiration and Excretion - The Excretory System
Filtration of Wastes
Each kidney contains about a million
tiny filtering units called nephrons.
Respiration and Excretion - The Excretory System
Previewing Visuals
Before you read, preview Figure 11. Then write three
questions you have about the diagram in a graphic organizer
like the one below. As you read, answer your questions.
How the Kidneys Filter Wastes
Q. Where are nephrons located?
A. In the kidneys
Q. What three main materials are filtered out of the blood?
A. Urea, water, glucose
Q. What happens to these filtered materials?
A. Most of the water and glucose are reabsorbed. Most of the
urea remains as urine.
Respiration and Excretion
Graphic Organizer
Blood flows into the nephron’s capillary cluster.
Water, urea, glucose, and other materials are
removed from the blood and flow into the capsule.
From the capsule, the substances flow into
a long tube.
In the tube, glucose, water, and some other
materials are reabsorbed.
Urine flows from the kidneys through the ureters to
the urinary bladder.