The body - The respiratory system Flashcards
Excretory organs
Lungs
Skin
Kidneys
What do the lungs excrete
Remove carbon dioxide and waste vapour from body
What does skin excrete
Remove water and salts (sweat)
What do the kidneys excrete
Remove waste in form of urine
The breathing system
Breathe in (inhale), take in oxygen from air.
Combines with food to give energy (oxidation).
Waste products (carbon dioxide + water) formed.
Get rid when breathe out (exhale).
Structure of the breathing system
Air passes through series of pipes as it goes from nose and mouth to lungs.
Passes through nose + mouth, warmed + hairs in nose filter.
Passes through space at back of mouth (pharynx)
Flap of skin (epiglottis) covers opening of trachea to prevent food in.
Passes through larynx (voice box), contains vocal cords.
Travels into trachea (windpipe).
Trachea divides into two tubes (bronchi). Bronchus divides again to form narrow tubes (bronchioli). At end are air sacs (alveoli). Here oxygen reaches blood + carbon dioxide removed.
Position of the lungs
In chest.
Like large pink sponges which expand as they are filled with air and shrink as air removed. Surrounded by rib cage, breast bone, back bone.
Heart is between lungs.
Excretion
Removal of waste from body
Function of the lungs
Take oxygen in
Remove carbon dioxide
Remove water
Exchange of gases
Alveoli (air sacs) have very thin walls, covered with capillaries (tiny blood vessels).
Oxygen passes from sacs through walls and into blood in capillaries. Carbon dioxide passes from blood into sacs (exchange of gases).