Respiratpry system

1. Lesson Overview The Respiratory System
Objectives 33.3
The Respiratory
System
-Identify the structures of the
respiratory system and describe
their functions.
-Describe gas exchange.
-Describe how breathing is
controlled.
-Describe the effects of smoking on
the respiratory system.

2. Lesson Overview The Respiratory System
Structures of the Respiratory System
The respiratory
system consists of
the nose, pharynx,
larynx, trachea,
bronchi and lungs.

3. Lesson Overview The Respiratory System
Nose
To keep lung tissue healthy, air entering the
respiratory system must be filtered, moistened, and
warmed; this all happens in the nasal cavity or nose.
Hairs lining the entrance to the nasal cavity filter and
trap large particles.

4. Lesson Overview The Respiratory System
Pharynx and Trachea
Air moves through the nose to a cavity at the back of the
mouth called the pharynx.
Air moves from the pharynx into the trachea, or windpipe.
A flap of tissue called the epiglottis covers the entrance to
the trachea.

5. Lesson Overview The Respiratory System
Larynx
Between the pharynx and the trachea is
the larynx, which contains two highly
elastic folds of tissue known as the vocal
cords.

6. Lesson Overview The Respiratory System
Trachea
Mucus produced in the
trachea continues to
trap inhaled particles.
Cilia lining the trachea
sweep both mucus and
trapped particles away
from the lungs toward
the pharynx, where
they can be swallowed
or spit out.

7. Lesson Overview The Respiratory System
Lungs
From the trachea, air
moves into two large
tubes called bronchi.
Each bronchus leads
to one lung.
Within each lung, the
large bronchus divides
into smaller
passageways called
bronchioles.

8. Lesson Overview The Respiratory System
Lungs
The bronchioles
continue to divide
until they end at a
series of tiny air
sacs called alveoli.
A network of
capillaries
surrounds each
alveolus.

9. Lesson Overview The Respiratory System
Gas Exchange
Gas exchange
happens at the
alveoli in the lungs
by diffusing across
the thin capillary
walls into the blood.

10. Lesson Overview The Respiratory System
Smoking
Three of the most dangerous
substances in tobacco smoke are
nicotine, carbon monoxide and tar.
Nicotine is an addictive stimulant that
increases heart rate and blood
pressure.
Carbon monoxide is a poisonous gas
that blocks hemoglobin from binding
with oxygen.
Tar contains at least 60 compounds
known to cause cancer.

11. Lesson Overview The Respiratory System
Effects on the Respiratory System
Tobacco smoke
paralyzes cilia in the
trachea, allowing
inhaled particles to
stick to enter the
lungs.

12. Lesson Overview The Respiratory System
Diseases Caused by Smoking
Chronic Bronchitis ~ In chronic bronchitis, the bronchi
become inflamed and clogged with mucus.
Emphysema ~ Long-term smoking can lead to emphysema,
the loss of elasticity and eventual breakdown of lung tissue.
Lung Cancer ~ Lung cancer is particularly deadly because, by
the time it is detected, it usually has spread to other areas
of the body.

13. Lesson Overview The Respiratory System
True or False
The process by which oxygen and carbon monoxide are exchanged
between cells, the blood, and air in the lungs is known as
respiration. _________________________
In your lungs, diffusion of oxygen from alveoli into capillaries stops
when oxygen concentrations in the blood are equal to oxygen
concentrations in the alveoli. _________________________
When you exhale, the rib cage rises and the diaphragm contracts.
_________________________
The brain controls breathing in a center located in the medulla
oblongata. _________________________
Nicotine is an addictive stimulant that decreases heart rate and
blood pressure. _________________________

14. Lesson Overview The Respiratory System
Answers
The process by which oxygen and carbon monoxide are exchanged
between cells, the blood, and air in the lungs is known as
respiration.False, carbon dioxide
In your lungs, diffusion of oxygen from alveoli into capillaries stops
when oxygen concentrations in the blood are equal to oxygen
concentrations in the alveoli. True
When you exhale, the rib cage rises and the diaphragm contracts.
False, inhale
The brain controls breathing in a center located in the medulla
oblongata. True
Nicotine is an addictive stimulant that decreases heart rate and
blood pressure. False, increases