Lungs - respiration, Biology

Assignment Help:

Lungs - Respiration

Lungs can be simple, characterised by air exchange with surrounding environment by diffusion only. These are called the diffusion lungs and are present in small animals such as pulmonate snails, small scorpions, sane spiders and some isopods. The other type - ventilation lungs are typical of vertebrates.

2440_Lungs - Respiration.png

Figure: Breathing Cycle in Frogs

The air passes through a tube into inflatable lungs where gas exchange takes place and oxygen poor, carbon dioxide rich air is then forced out usually through the same tube. This is known as tidal flow of air. Ventilation of the lungs can take place in two different ways:

1) By using a pressure pump as in amphibians. Figure shows the process of ventilation in frog. The inflation of lungs depends on positive pressure bucco pharengeal pump. The nares remain open while glottis is closed (the air does not enters the lungs). The floor of the buccal cavity is raised and lowered periodically. At irregular intervals the glottis is open and nares are closed. The floor of the buccal cavity is raised forcing air into the lungs. As a result the frog can take in air several times without exhaling and blow itself up to considerable size. The glottis can close and while the air remains inside the lungs the cycle is replated in the buccal cavity.

2) By using a suction pump. Exhalation can be passive and inhalation is aided by muscle contraction or as in mammals, by contraction of muscular dome shaped diaphragm and external intercostal muscles lifting the ribcage. This decreases the pressure in the pleural space so causing the lungs to expand and air flows in.

 


Related Discussions:- Lungs - respiration

Parasite and host during incubation period, Parasite and host during incuba...

Parasite and host during incubation period Incubation period is the second stage in the process of a disease. It is the time between the day of infection to the appearanc

What is the kind of life cycle present in pteridophytes, Q. What is the kin...

Q. What is the kind of life cycle present in pteridophytes? Like all plants pteridophytes present diplobiontic (alternation of metagenesis or generations,) life cycle.

What gases was the earths primitive atmosphere, Before the emergence of lif...

Before the emergence of life of what gases was the earth's primitive atmosphere constituted? The earth's primitive atmosphere was basically produced of methane, hydrogen, ammon

Addition of glycine to the physiological saline, Addition of glycine to the...

Addition of glycine to the physiological saline A complete motor neuron is removed from a frog and placed in a large volume of normal physiological saline.  The neuron is heal

Of what subunits are ribosomes are made, Q. Of what subunits are ribosomes ...

Q. Of what subunits are ribosomes are made? Ribosomes are made of two subunits the small subunit and the large subunit. These subunits are made of proteins and ribosomic RNA (r

What is intracardiac repair of tetralogy of fallot, What is Intracardiac Re...

What is Intracardiac Repair of Tetralogy of Fallot ? Technique : The essential steps are: (I) relief of right ventricular outflow obstruction, and (2) closure of ventricular

Classification, What is omnispective classification

What is omnispective classification

What factors are altered when cells are moved, Which factors are altered wh...

Which factors are altered when cells are moved from an in vivo to an in vitro environment, and how do cells respond to these changes?

Nutrition, The oxidation of sugar in the cell of higher organisms takes pla...

The oxidation of sugar in the cell of higher organisms takes place in the ?

What volume of water to make solution, You need to prepare 500 ml of a solu...

You need to prepare 500 ml of a solution containing 10 mM Tris, 0.15 M NaCl and 1 mg/ml SDS. At your work disposal are stock solutions containing 1 M Tris, 2.5M NaCl and 10% (w/v)

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd