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

Limitations of five-kingdom classification, Limitations of Five-Kingdom Cla...

Limitations of Five-Kingdom Classification As already pointed out, each system of classification has its own limitations. The two-kingdom system has outlived its usefulness as

What are the types of neurons, According to the function of the transmitted...

According to the function of the transmitted neural impulse which are the types of neurons? How different are the concepts of afference and efference of the neural impulse transmis

Undescended testes (cryptorchidism), Undescended Testes (Cryptorchidism) ...

Undescended Testes (Cryptorchidism) Undescended testes is a ccmmon disorder. It may be unilateral and may be classified as ectopic cryptorchidism, when the testes are normal

Determine the wechsler intelligence scales, Determine the Wechsler Intellig...

Determine the Wechsler Intelligence Scales This test is given according to manual instructions and is not modified in any way. Most clinicians use the most current revision of

Precipitation-water cycle, Precipitation Precipitation literally means ...

Precipitation Precipitation literally means falling from a height. In case of water, precipitation includes all forms in which atmospheric moisture descends to earth; rain, sno

Which type of cell came first in evolution, Which type of cell came first i...

Which type of cell came first in evolution - the eukaryotic cell or the prokaryotic cell? This is an interesting problem of biological evolution. The most accepted hypothesis a

How do biodiversity vary during the ecological succession, Q. How do biodiv...

Q. How do biodiversity, the total number of living beings and the biomass respectively vary during the ecological succession? The Biodiversity, the biomass of an ecosystem and

Plant cell wall react when it is placed in hypotonic medium, How does the p...

How does the plant cell wall react when it is placed under hypotonic medium? Ans) The plant cell wall (the covering of the cell outside to the cell membrane) is made of cellulos

Test cross, TEST CROSS Crossing of F hybrid with its homozygous recessi...

TEST CROSS Crossing of F hybrid with its homozygous recessive parent is called test cross and the progeny of test cross is called test cross progeny. A .      Monohybrid Te

Classification, list the major species of echinodermata

list the major species of echinodermata

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