Respiration in Ak grasshopper &general

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

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

RESPIRATION

External Respiration(Breathing)

Internal Respiration

(Cellular respiration)

Aerobic Respiratio

n

Anaerobic Respiratio

n

2 stages

2 types

External respiration (Breathing)

The exchange of respiratory gases (oxygen and carbon dioxide) between the body and the environment

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 :1. Aerobic respiration2. Anaerobic respiration

The respiratory structure and breathing mechanism of insects

• Air enters into body through tiny holes spiracles

• Use to avoid water loss

• A cavity atrium or entrance is present

• Air passage is controlled by Valves

• Surrounded by peritreme.

Spiracles

Elastic in nature

Cuticular pipe like apparatus

Thick, helical and thread like layer taenidia

give flexibility

Filled with air shows silvery appearance

Trach

eae

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

Air-Sacs

tracheae are expanded in many parts to make thin

walled, collapsible structure

act as air reservoir

shiny white vesicle, filled with air

Assist flight by reducing gravity of insects

Sound resonator of tympanic membrane

Heat insulations

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.

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.

Conditions in Resting and Active Insect Tissues

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.