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

Overall senescence - senescence, Overall senescence - Senescence Only ...

Overall senescence - Senescence Only the parts above the ground level i.e.  The aerial parts die whereas the underground parts survive For example, potato.

Define contains permitted synthetic food colour, Normal 0 fa...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Muscle, In a word, what process provides the energy for muscle contraction

In a word, what process provides the energy for muscle contraction

Offspring, #q1. If offspring exhibit a 3:1 phenotypic ratio, what are the g...

#q1. If offspring exhibit a 3:1 phenotypic ratio, what are the genotypes of a parent?uestion..

Cells, what are golgi apparatus

what are golgi apparatus

Morphallaxis - regeneration, Morphallaxis - Regeneration This kind of ...

Morphallaxis - Regeneration This kind of regeneration takes place in plants, sponges and coelenterates such as jelly fishes and hydra. The missing parts are replaced via reorg

What fraction of the total number of possible, Assuming that all human prot...

Assuming that all human proteins are 300 amino acids long, what fraction of the total number of possible different proteins is found in the human body?

Define some precautions for estimation of amount of bacteria, Define some P...

Define some Precautions for Estimation of the Amount of Bacteria? 1. Dilution should be made carefully. 2. Use fresh sterile pipette for making each dilution. 3. Aseptic

What is the genotypical proportion of the gametes, Which is the type of gam...

Which is the type of gamete (for a given trait) produced by a dominant homozygous individual? What is the genotypical proportion of these gametes? What about a recessive homozygous

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