Transcript HUMAN RESPIRATION

THE HUMAN
RESPIRATORY
SYSTEM
• Aim: How do the structures of the
respiratory system exchange gases with
the environment?
• Do Now: What is the purpose of
having a respiratory system?
• Homework: Read 574-576; do Self
Check Questions # 1-4.
What is Respiration?
Respiration:
the process of
exchanging
gases between
the body and the
environment.
What is a Respiratory Surface?
• In all organisms, the exchange of gases
must occur across a respiratory surface.
– Must be moist
– Must be very thin so that gases are
able to pass through
– Must be a supply of oxygen
– Must be closely connected to the
transport system to deliver gases to
and from cells
The Human Respiratory System
Organs of the Respiratory System
The Nose
• The nose serves
to filter,
moisten, and
warm inhaled air
before it reaches
the lungs.
What is the Pharynx?
•Pharynx – “throat”
•Air moves from the nasal
passage  the pharynx
• Epiglottis – flap of tissue covering the
trachea during swallowing preventing food
from entering the lungs.
The Larynx
• “voice box”
• Larynx contains vocal cords used to speak.
• Air passes from the pharynx  larynx
• Food passes from the pharynx  esophagus
The Trachea
• “the windpipe”
• Kept open by
rings of cartilage
• Lined with cilia
and mucous
membranes
• Aim: How do the structures of
the respiratory system allow you
to breathe?
• Do Now: What does the nose do
to the air that you breathe? What
is the role of the cilia that line the
trachea?
• Homework:
The Bronchi
• Trachea divides
into tubes called
the bronchi
• Bronchi enter
lungs and branch
off into tiny tubes
called bronchial
tubes
The Bronchioles
• AKA: Bronchial Tubes
• Thin network of microscopic tubes
found inside the lungs.
Alveoli: The Air Sacs
Alveoli: The Air Sacs
• Found in the LUNGS
• Each bronchiole ends in a tiny alveoli
• “cluster of grapes”
• The alveoli are the respiratory surface
• Exchange of O2 and CO2 occurs HERE!
• Alveoli are surrounded by capillaries (so
O2 enters blood).
Gas Exchange
• Aim: How do the structures of the
respiratory system work together
to allow you to breathe?
• Do Now: Explain how gas
exchange occurs in the lungs
• Homework:
How do we Breathe?
What is Going on Inside
When You Breathe?
• Composed of two phases:
–Inhalation – draws air into
lungs
–Exhalation – expels air from
lungs
What is the Diaphragm?
• Muscle that
contracts and
relaxes to
move gas into
and out of the
lungs.
Inhalation
• Ribs are pulled up and out
• Diaphragm is pulled downward
• Chest cavity is enlarged
• Lungs expand
• Air pressure in chest decreases
Exhalation
• Diaphragm relaxes and pushes
upward
• Rib muscles relax – ribs drop
• Size of chest cavity decreases
• Air is squeezed out of lungs
• Air pressure in chest increases
Breathing
Rate of Breathing
• If CO2 levels in the blood
increase, your breathing rate
INCREASES.
• If CO2 levels decrease,
breathing rate DECREASES.
• Aim: What are the malfunctions of the
human respiratory system?
• Do Now: Is it INHALATION or
EXHALATION?
– The ribs are pulled up and out, the diaphragm
is pulled down. ___________
– The lungs decrease in size, the diaphragm is
pushed upward. __________________
– The chest cavity decreases in size, the
pressure inside the chest increases.
________________
• Homework:
DISEASES OF THE
RESPIRATORY SYSTEM
Asthma
• Severe allergic reaction where muscles
surrounding bronchial tubes contract
and make breathing extremely difficult.
Asthma
Bronchitis
• Inflammation of the bronchial
tubes
• Passageways become swollen and
clogged with mucus
• Results in severe coughing and
difficulty in breathing
Bronchitis
Emphysema
• Walls of alveoli breakdown decreasing the
respiratory surface
• Causes shortness of breath, difficulty
exhaling and decreased lung capacity
*Smokers run a greater risk of developing
emphysema*
Emphysema
Pneumonia
• Alveoli become
filled with fluid
• Caused by a
bacterial or viral
infection
Lung Cancer
• Disease in which
tumors form in
the lungs from
irregular and
uncontrolled cell
growth
Let’s Summarize…
1. What happens during respiration in all
animals?
2. What are the requirements of a
respiratory surface?
3. How are dirt and other small particles
removed from the air humans breathe?
4. List in order the structures that air
passes through as it travels from the
external environment to the lungs.
Let’s Summarize…
5. Why are cilia important to the function of
the lungs?
6. At what point does the oxygen that you
inhale actually enter into your blood?
7. What happens to the rib cage during
inhalation and exhalation?
8. What happens to the diaphragm during
inhalation and exhalation?
Let’s Summarize
9. What system of the body carries the
oxygen taken in by the respiratory system
to all cells in the body?
10. What is the scientific term for the “back
of the throat”?
11. What is the role of mucous in the
respiratory system?
What Should We Study?
• Be able to :
– Define all vocabulary in the respiratory system –
including structures
– Trace a drop of air from environment to the
alveoli in the lungs.
– Label diagrams of the respiratory system.
– Explain a malfunction of the respiratory system
and what causes it.
– Explain the function of each of the structures in
the respiratory system.
– Discuss what makes a good respiratory surface
– and where our respiratory surface is found.