Respiration in Ak grasshopper &general

Presentation on Respiration in insects General and specific as Taking the Ak grasshopper as a model insects

1. Introduction to Respiration Respiration in Insects (General) Respiration in Insects ( AkGrassopper as model) Reference Research Paper 2013

2. What is respiration?? Refer to the process of obtaining oxygen and delivering it to the cells for cellular respiration and removing carbon dioxide produced by cells

3. Respiration External Respiration (Breathing) Internal Respiration (Cellular respiration) Aerobic Respiration Anaerobic Respiration 2 stages 2 types

4. External respiration (Breathing) The exchange of respiratory gases (oxygen and carbon dioxide) between the body and the environment

5. Internal respiration ( cellular respiration) A metabolic process which occurs in cells, involves oxidation of organic molecules to produce energy (in the form of ATP) Controlled by enzymes Two types : Aerobic respiration Anaerobic respiration

6. The respiratory structure and breathing mechanism of insects

7. Air enters into body through tiny holes spiracles U se to avoid water loss A cavity atrium or entrance is present Air passage is controlled by Valves S urrounded by peritreme . Spiracles

8. E lastic in nature Cuticular pipe like apparatus Thick , helical and thread like layer taenidia give flexibility F illed with air shows silvery appearance Tracheae

9. Tracheoles The network of tracheae Diameter less than 1µm (0.2-0.3µm ) Gaseous exchange Lie within each cell Its lining not shed down on molting

10. Air-Sacs tracheae are expanded in many parts to make thin walled, collapsible structure act as air reservoir shiny white vesicle, filled with air A ssist flight by reducing gravity of insects Sound resonator of tympanic membrane H eat insulations

11. Respiratory System In grasshopper, the tracheal system consists of 10 pairs of spiracles, located laterally on the body surface. Of these, 2 pairs are thoracic and 8 pairs are abdominal. The spiracles are guarded by fine hairs to keep the foreign particles out and by valves that function to open or close the spiracles as required. The spiracles open into small spaces called the atria that continue as air tubes called the tracheae. The tracheae are fine tubes that have a wall of single layered epithelial cells. The cells secrete spiral cuticular thickenings around the tube that gives support to the tubes .

12. Mechanism:- The first four pairs of spiracles are involved in inspiration or drawing in of air that is oxygen-rich. This air passes through the trachea and the air sacs to reach the tracheoles .

13. Conditions in Resting and Active Insect Tissues

14. The ends of the tracheoles are filled with fluid. This end enters into the tissue. The ends of the tracheoles are also devoid of cuticle and therefore the respiratory surface is very thin making the diffusion of oxygen into the cells easy. As respiration occurs in the cell, the products of respiration accumulate in the cell and this forces the fluid in the tracheoles to enter the tissue. The exit of fluid creates low pressure in the tubes and draws in more oxygen to the tissues where it is needed.The carbon dioxide produced is detected by the chemo receptors which make the muscles near the spiracles contract. This pushes the air out. The last six pairs of spiracles are involved in expiration of air.Thus , in grasshopper there is ventilation or circulation of air as the oxygen-rich air is inhaled through the first four spiracles and the carbon dioxide-rich air is exhaled through the remaining six pairs of spiracles. In insects, therefore, the respiratory system is independent of the circulatory system.