Frog Respiratory System Short Notes | Free Biology Notes

In this article we will discuss about the frog respiratory system

Frog Respiratory System

• The process of gaseous exchange is called respiration
• The frog respiratory system help for respiration
• The frog respiratory system different in adult and larva
• Branchial respiration occurs in case of tadpoles by means of external gills
• Respiration in adult frog occurs through 3 different ways
  1. Cutaneous respiration: through moist surface of outer skin.
  2. Buccal respiration: through lining of bucco pharyngeal cavity.
  3. Pulmonary respiration: through lungs.

Cutaneous Respiration in Frog

• The respiration through skin is called cutaneous respiration
• The frog is under water or hibernating, it is the only mode of respiration
• The skin of frog is thin and has fine blood vessels
• Due the presence of mucous gland the skin of frog always remains moist
• During gaseous exchange the oxygen first dissolve moisture of body and then diffuse into the blood capillaries
• The carbon dioxide diffuses out from the blood into the environment
• Movement is not required in cutaneous respiration as skin remains exposed to air or water

Buccal Respiration in Frog

• Respiration done through the buccopharyngeal cavity then it is called buccopharyngeal respiration
• The floor of the buccal cavity is alternately raised and lowered
• The buccal cavity consists of moist mucous membrane and richly supplied with blood capillaries
• The air enters into the cavity through external nares and gaseous exchange takes place through the lining of buccal cavity
• The glottis closed during buccal respiration

Pulmonary Respiration in Frog

• The respiration through the lungs is called pulmonary respiration
• Frog respires by lungs when the need for oxygen is great
• Passage through which the air enters and leaves the lungs is termed as respiratory tract
• Respiratory tract consists of nostrils, buccopharynheal cavity, glottis, bronchi and lungs
• Nostrils: A pair of external and internal nostrils present
• Buccopharynheal cavity: the space between buccal cavity and pharynx
• Glottis: A slit like opening
• Bronchi: it is a pair of small tubes
• Lungs: pair of sacs. Numerous small air sacs are present in the lungs called alveoli. Alveoli help for gaseous exchange.

How Respiratory System Works In Frog?

• The inspiration and expiration of the air is done by the action of the buccal cavity

Inspiration

• The process of intake of air is called inspiration
• Now, the sternohyal muscles contract.
• The floor of buccal cavity is lowered
• Buccal cavity is enlarged and the air is drawn into the buccal cavity through the nostrils
• Now, the glottis opens and the closes the nostrils
• The pterohyal muscles contracts which raises the floor of buccal cavity
• By this mechanism the air passed into lungs
• In lungs, alveoli are filled with air and gaseous exchange takes place between blood and alveoli by diffusion.

Expiration

• The process of exhaling of CO2 is called expiration.
• The glottis closes when lungs are filled with air
• Soon, the glottis opens.
• The air in the lungs are driven out into the buccal cavity by lowering its floor
• The glottis closes when the buccal floor is raised again.
• Now, the air is expelled through the opened nostrils to outside.