Respiration in Frog
1. What is respiration? Explain different modes of respiration found in a frog.
The process of gaseous exchange (O2 and CO2), i.e. intake of oxygen and liberation of carbon-dioxide and utilization of oxygen to breakdown food to release energy is called respiration. The energy is released during the process of respiration.
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
There are three types of respiration in frog:
1. Pulmonary respiration: Frog respires by pulmonary respiration when the need for oxygen is great, i.e. during the time of swimming and jumping. The respiration through the lungs is called pulmonary respiration. Many organs function during the respiration:
i) External names: A pair of opening lies between the eyes and snout.
ii) Internal nares: A pair of the small opening is found in between the maxillary and vomer teeth on the buccal cavity.
iii) Nasal passage: space between external and internal nares.
iv) Buccopharynheal cavity: the space between the buccal cavity and pharynx.
v) Glottis: A slit-like opening.
vi) Bronchi: It is a pair of small tubes.
vii) Lungs: There is a pair of lungs that are thin-walled elastic sacs. They are present within the thoracic cavity on either side of the heart. Numerous small air sacs are present in the lungs called alveoli. The alveoli are very thin-walled and supplied by blood vessels. The air enters into the alveoli of the lungs through the external nares, internal nares, buccopharyngeal cavity, glottis, laryngotracheal camber, and bronchi. The alveoli increase the respiratory surface of the lungs.
Buccopharyngeal respiration: While the respiration is done through the buccopharyngeal cavity then it is called buccopharyngeal respiration. The buccal cavity consists of moist mucous membranes and richly supplied with blood capillaries. The lungs do not take part in this respiration. The air enters into the cavity through external nares and gaseous exchange takes place through the lining of the buccal cavity between blood and oxygen (air) present in the cavity by the diffusion process.
Cutaneous respiration: The skin consists of the chief respiratory organ. The respiration through the skin is called coetaneous respiration. During hibernation and destination, the frog totally depends on this type of respiration.The skin of the frog is thin and has fine blood vessels. Due to the presence of a mucous gland, the skin of the frog always remains moist.During the gaseous exchange, the oxygen first dissolves moisture of the body and then diffuses into the blood capillaries. And the carbon dioxide diffuses out from the blood into the environment.