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

Effects on health - consequences of air pollution, Effects on Health - Cons...

Effects on Health - Consequences of Air Pollution Since the air pollutants are inhaled they attack various parts of the respiratory system on their route to air sacs. Once the

A protein is normally found inside of a lipid bilayer, A protein is normall...

A protein is normally found completely within the inside of a lipid bilayer. The protein likely has: a) Mostly hydrophobic side chains, pointed outwards, with the peptide backbo

Aquatic and terrestrial plant, what is common between aquatic and terrestri...

what is common between aquatic and terrestrial plants

Why are the tropical forests also known as stratified forest, Why are the t...

Why are the tropical forests also known as stratified forests? In tropical forests tall trees of various species have their crowns forming a superior layer under which diverse

Ionosinin ic pathway , how ionosinic pathway ric acid from ammonia forms ...

how ionosinic pathway ric acid from ammonia forms u

Harshey-chase experiement, What is the Harshey-chase experiement .explain i...

What is the Harshey-chase experiement .explain in detail

Deficiency diseases-thiamine deficiency (hypothiaminosis), Thiamine deficie...

Thiamine deficiency (hypothiaminosis) Thiamine deficiency is characterized by signs of nervous system. The primary  thiamine deficiency is not common in animals. However, seco

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