GASEOUS EXCHANGE Respiratory surface Respiratory System in Human

GASEOUS EXCHANGE Respiratory surface Respiratory System in Human Control of breathing Gaseous exchange in Insect Gaseous exchange in Fish Gaseous exchange in Plant

Respiratory surface Small organisms surface volume ratio is large Larger organism surface volume ratio is small

Characteristics of respiratory surface Large surface area 2. Moistened surface 3. Thin and freely permeable to gases 4. With transport system 1.

Types

Human Respiratory System

Lung tissue

Mechanism of Breathing Animation

Treatment to inhaled air 1. Warmed nostrils by capillary in 2. Moistened by mucus 3. Cleaned and filtered cilia and mucus by hair,

Lung capacities Volume of air

Control of Breathing Respiratory centre Chemoreceptor p. CO 2

chemoreceptor 1. Peripheral chemoreceptor Detect both Po 2 and PCO 2 Carotid bodies, aortic bodies 2. Central chemoreceptors Detect PCO 2 Medulla Effect of PCO 2 is larger than Po 2

Respiratory centre l. In medulla oblongata l. Receive impulse from chemoreceptor l. Send impulse to diaphragm and intercostal muscle l. Change rate and depth of breathing

Effect to lung lp. O 2 decrease and p. CO 2 increase rate and depth of breathing increase lp. O 2 increase and p. CO 2 decrease Rate and depth of breathing decrease

Other effect lp. CO 2 increase l. Heart : rate increase l. Blood vessel: vasodilation l. Increase rate and volume of CO 2 transport

Partial pressure of CO 2 p. CO 2 increase Detected by chemorecetor Impulse to respiratory centre Impulse to intercostal and diaphragm muscle by efferent nerve Rate and depth of breathing increase p. CO 2 back to normal Feedback

Gaseous Exchange in insects Mechanism Abdomen movement, fluid movement

Trachea

Spiracle

During rest exercise less more fluid During exercise

Breathing in fish

Gill

Gill photo

Where is gaseous exchange taking place? Buccal surface Skin Gill in tapole

Bird

Gaseous Exchange in Plant No special organ for breathing but some special features in various organs for increasing surface area Leave Stem Root

Leave

Root Hair

Lenticel