The Lungs mechanism of inhalation and exhalation

biology
class 10
the lungs
mechanism of inhalation and exhalation

1. THE LUNGS MECHANISM OF INHALATION AND EXHALATION

2. THE LUNGS: Respiratory organ Two lungs (left lung and right lung) small because it large because it has two lobes has three lobes

3. LOCATION Lungs are located in thoracic cavity. What is thoracic cavity? The  thoracic cavity , also called the  chest cavity , is a  cavity  of vertebrates bounded by the rib cage on the sides and top, and the diaphragm on the bottom.

4. THORACIC CAVITY: There are 12 pairs of ribs Muscles between rib bones are called intercostal muscles Thick muscular structure below the lungs is known as diaphragm.

5. CHARACTERTISTICS OF LUNGS Lungs are spongy and elastic. Lungs have blood vessels. Blood vessels of lungs have a specific name that is pulmonary arteries and pulmonary veins.

6. FUNCTION OF PLEURAL MEMBRANE: Each lung is enclosed by two membranes which are 1.Outer pleural membrane 2.Inner pleural membrane Membrane encloses a fluid which provides lubrication for expansions and contraction of lungs.

7. INHALATION EXHALATION The intake of air from environment into lungs is known as inhalation The impure air is expelled out from lungs during exhalation.

8. INHALATION EXHALATION Rib muscles contract and ribs are raised. Pressure on lungs reduces. As a result the lungs expand. Rib muscles relax and ribs came in original position. Pressure on lungs increases. As a result lungs contract.

9. INHALATION EXHALATION The air rushes into lungs to equalize the pressure on both sides. The dome-shaped diaphragm contract and is lowered. The air expelled out of lungs to equalize the pressure on both sides. The diaphragm muscles relax and it gets raised dome shape.

10. Humans breathe 16-20 times per minute in normal circumstances i.e. at rest. During exercise or other hard physical works the breathing rate increases up to 30-40 times per minute. The rate of breathing is controlled by respiratory center in brain.