3.1. The key to respiration
COAL + OXYGEN
ENERGY (HEAT) + CARBON DIOXIDE + WATER
GLUCOSE (FOOD) + OXYGEN
ENERGY + CARBON DIOXIDE + WATER
Food and oxygen react in our cells to give us energy.
Respiration is the release of energy from food.
Carbon dioxide is toxic and the cells have to expel it.
NOSE AND MOUTH
PHARYNX: Common to digestive and respiratory system.
It has the eppiglotis that prevents food from entering the trachea.
LARYNX (VOICEBOX): Allows us to make sounds
with the vocal cords, protected by cartilage.
TRACHEA: Passes air to lungs.
RINGS OF CARTILAGE: These surround the trachea,
bronchi and bronchioles, they keep the airways open.
BRONCHI: Two tubes that carry air into and out each lung.
LUNGS: Two lungs made up of alveoli.
BRONCHIOLES: Tiny tubes taking air to the alveoli.
ALVEOLI: Blind tiny air sacs, surrounded by tiny blood vessels;
oxygen passes from the alveoly into the blood,
carbon dioxide passes from the blood into the alveoli.
DIAPHRAGM: A sheet of muscle that moves down to draw air into the lungs,
and up to expel the air out of the lungs.
3.3. Respiratory movements
There are two movements: inhalation and exhalation
http://www.youtube.com/watch?v=GiFzg1Ek-_E Lungs in Motion
Intercostal muscles contract.
The diaphragm contracts and moves downward
Air enters the lungs.
Intercostal muscles relax.
The diaphragm relaxes and moves upward .
The air is pushed out from the lungs and leaves them
3.4. Exchanging gases
Gas exchange between the lungs and the blood takes
place in the alveoli.
Oxygen moves out the alveolus through its thin wall,
across the wall of the blood capillary and into the blood.
Carbon dioxide moves out of the cell and into the
blood. Bloodstream takes them to the lungs. From the
alveoli, they are breathed out by the lungs.
Activities 3 and 4 page 67
Diseases of the respiratory system
Asthma narrows the airways by causing an allergy-induced spasms
of surrounding muscles or by clogging the airways with mucus.
http://www.youtube.com/watch?v=o2OcGgJbiUk Respiratory system 3D
The smoke particles irritate the lungs causing them to produce more mucus
which cannot easily be cleared.
This could lead to bronchitis, emphysema or
Carbon monoxide in cigarette smoke replaces oxygen in the blood.
A smoker has to breathe faster.
This lead to heart strain which could cause a heart
Smoking during pregnancy reduces the oxygen available to the baby.
This can cause the stunted growth of the baby.