16 Respiration system and lungs
RESPIRATORY SYSTEM
The respiratory system is the system in the human body that enable us to breathe.
Parts of the Respiratory system
1. Upper respiratory tract: (i) nose,(ii) Mouth(iii) Beginning of trachea
2. Lower respiratory tract :
a. The trachea - The tube connecting the throat to the bronchi.
b. The Bronchi - tq bronchi (tubes) to the left and right lungs.
c. The Bronchiole - The bronchi branchia branches off in to smaller tubes called bronchiole which ends in the pulmonary alveolus.
d. Pulmonary alveoli - Tiny sacs delineated by a single layer membrane with blood capillaries at the other end.
e. The exchange of gases takes [place through membranes of the pulmonary alveolus which always contains air: oxygen(o620 is absorbed from the air
into the blood capaliiareis and the action of the heart circulates it through all the tissues in the body. At the same time, cO^2 is transmitted from the blood
capillaries in to the alveolus and then expelled through the bronchial and the upper respiratory tract.
The inner surface of the lungs where the exchange of gases takes place is very large, due, to the structure of the air sacs of the alveoli.
The Lungs.
a. There is a pair of lungs in the thoracic cavity.
b. its color is red and looks like sponge.
c. Lung is surrounded by amemberance called pleural membrane.
d. There is a network of blood capillaries.
e. Hero oxygen enters in to the blood and CO^2 comes out