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

What is sustainable agriculture, What is sustainable agriculture? Desc...

What is sustainable agriculture? Describe the contribution of biopesticides and biofertilisers in sustainable agriculture.

Foliose lichen stage - xerarch, Foliose Lichen Stage - Xerarch As ment...

Foliose Lichen Stage - Xerarch As mentioned earlier, the weathering of the rocks and the decaying of the crustose lichens results in the formation of soil on the otherwise bar

Define evolution of food processing, Define Evolution of food processing? ...

Define Evolution of food processing? 8000 - 7000 BC. Mankind first began farming, growing crops and raising animals for food instead of hunting and gathering for food.

Population and sigmoid curve, Name two possible why the number of live bact...

Name two possible why the number of live bacteria cell have reached the stationary growth by 60hrs and start to die off after 12hrs?

Nutrition, how do carnivorous feed

how do carnivorous feed

How much of solution to add 10ng of dna in a reaction, I dissolve 4µg of DN...

I dissolve 4µg of DNA in 1mL of water. How much of this solution would I need in order to add 10ng of DNA in a reaction?

What is kingdom plantae or how organism included in plantae, What is Kingdo...

What is Kingdom Plantae and what organism included in Plantae? Kingdom Plantae :  includes organisms that are eukaryotic, multicellular, photosynthetic. Their cells also cont

What is the transcription of the gene downstream, A substitution mutation o...

A substitution mutation occurs in the GRE making it unrecongnizable to the glucocorticoid receptor. What impact would this have on the transcription of the gene downstream of this

Define prevention in the prevalence of overweight or obesity, Define Preven...

Define Prevention in the prevalence of overweight or obesity? It is believed that the increase in prevalence of obesity worldwide is more due to the environment that has become

Explain acyclovir, Explain Acyclovir Available in topical, oral, and in...

Explain Acyclovir Available in topical, oral, and intravenous (IV) formulations, acyclovir is used to treat herpes simplex virus (HSV) and varicella-zoster virus (VZV) infectio

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