RESPIRATORY SYSTEM

OF A FROGDal Vladimir CaringalDenise Christine Cruz

Erika Laine CruzMichelle Cuacoyes

These are the organs concerned with the exchange of gases forms respiratory system. In frog,

respiration takes place through moist skin, lining of bucco-pharyngeal cavity and lungs. However in

tadpole larva, respiration takes through gills.

Types of Respiration

1. Cutaneous Respiration

Through moist skin

Skin is richly supplied with alone vessels and is permeable to gases. Oxygen get dissolved in moist surface of skin them exchange of gases takes place by diffusion.

It is only mode of respiration during hibernation or aestivation or when frog is under water.

Oxygen diffuses through skin to capillaries and is carried by blood and CO2 diffuses back to blood from cells and is discharged out.

2. Buccal Respiration

It takes place on land during mouth and glottis remains closed while nostrils remain open. 

The floor of buccal cavity is alternately raised and lowered so that air is drawn into and expelled out of buccal cavity through Nostrils

The epithelial lining of buccal cavity is moist and highly supplied with alone capillaries and exchange of gases takes place through it.

3. Pulmonary Respiration

LUNGS

Positive pressure

main release of CO2

In this process, frog keeps its mouth closed. Air reaches buccal cavity through nostrils. Nostrils are closed floor of buccal cavity is raised; glottis opens, and air is pushed into the lungs. 

INSPIRATION The process in which lungs are filled up with air.

1. During it, glottis and mouth remains closed while nostrils remain open.

2. The sternohyal muscles contract due to which the floor of buccal cavity is lowered.

3. Thus, the buccal cavity get enlarged and air comes into buccal cavity through nostrils. 

4. Now the glottis opens and nostrils are closed.

5. Now petrohyal muscles contract which raises the floor of buccal cavity.

6. This decreases size of buccal cavity and air passes into lungs through glottis.

Process which lungs are emptied. When lungs are filled with air glottis closes

and air remains in lungs for some time.  At this time, the floor of buccal cavity is

raised and lowered to carry buccal respiration.

Now glottis opens and floor of buccal cavity is towered by the contraction of sternohyal muscles.

EXPIRATION

Organs Associated with Respiration

Lungs

LUNGS Alveoli – small thin walled

chambers which greatly increase the are of the lungs

 When lungs are filled with air, then exchange of gases occurs between blood and air in lungs at the site of alveoli.

During this, the exchange of gases occurs between blood and air present in buccal cavity. 

After this air is removed from the lungs. Frog uses its nostrils and floor of buccal cavity for inspiration and expiration.

Oxygen present in the air is dissolved in moisture present on lining of lungs.

Then oxygen is diffused into the blood where it combines with hemoglobin to form oxyhaemoglobin. 

This oxygenated blood goes to all parts of the body by means of capillaries. Where oxygen separates from oxyhaemoglobin molecules and is absorbed by the cells. Carbon dioxide from cells comes out into the blood, which carries it to the lungs, and from here carbon dioxide is expelled.

Organs Associated with Respiration

Respiratory Tract

the passage through which air enters and leaves lungs

 Consists of: External nares Nasal membranes Internal nares Buccal cavity Glottis

RESPIRATORY TRACT