Transcript THE RESPIRATORY SYSTEM

THE RESPIRATORY
SYSTEM
Section 3.1
THE RESPIRATORY SYSTEM
What is the purpose of the respiratory system?
• Responsible for absorbing
oxygen from the air and
removing carbon dioxide
from the blood
• The main parts are trachea,
lungs and diaphragm
• Contained within the chest
cavity, which is surrounded
and protected by the rib
cage
BREATHING
How do we breathe?
Breathing – the regular movement
of air into and out of the lungs
•Breathing is automatic, meaning
that it is controlled by the body
- conscious breathing only
controls how deeply or how
fast we breathe
- diaphragm and muscles
between the ribs contract and
relax to allow you to breathe
•Diaphragm – large, thin sheet of
muscle that spreads across the
chest cavity below the lungs
BREATHING - Inhalation
• Inhalation: taking air into
your lungs
- Diaphragm contracts and
flattens, rib muscles
contract
Inhalation
Exhalation
- Chest cavity becomes
larger (volume increases);
therefore pressure
decreases.
- Air is forced into the
lungs
BREATHING - Exhalation
• Exhalation: releasing air from your lungs
- diaphragm relaxes and becomes dome-shaped, rib
muscles relax
- chest cavity becomes smaller (volume decreases);
therefore, pressure increases.
- air is forced out of the lungs
AIR TRAVEL
• nasal cavity and/or mouth: where
air enters body
• epiglottis: a flap of tissue at the
top of the trachea that covers of
opening of the trachea to prevent
food or water from accidentally
going into the lungs
• trachea: hard, ridged tube that
leads air into the lungs
- ridges are rings of cartilage that
keep the trachea open
• bronchi: smaller tubes that deliver
air to small air sacs in the lungs
(called alveoli)
RESPIRATION
• Respiration is the process of gas exchange between the
lungs and the blood (exchange of O2 and CO2)
• ‘Breathing’ is the mechanical movement of air into and
out of lungs
RESPIRATION
• Oxygen from the air diffuses through cell membranes into the
bloodstream, where it is then distributed to all the cells in the body
• Carbon dioxide (a waste product of cells) diffuses through cell
membranes to the bloodstream, where it is then returned to the
lungs to be exhaled
• The alveoli is where the exchange of oxygen and carbon dioxide
takes place