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 are the typical fauna of the temperate forests, What are the typical v...

What are the typical vegetation and the typical fauna of the temperate forests? In the temperate forest deciduous trees predominate. Mammals are originated in great number, as

What is the role of plant cells, What is the role of Plant Cells? Plant...

What is the role of Plant Cells? Plant cells function essentially in the same manner as other eukaryotic cells, but there are three unique structures which set them apart. Plas

How different are pteridophytes from bryophytes, Q. How different are pteri...

Q. How different are pteridophytes from bryophytes regarding substance transport? Pteridophytes are tracheophyte (vascular) plants that are they have tissues specialized in con

What is panspermia, What is panspermia? The Panspermia is a hypothesis ...

What is panspermia? The Panspermia is a hypothesis that describes life on earth as not originated from the planet. The thought is that the first living beings that colonized th

Define the causes of instrument fracture, Define the Causes of Instrument F...

Define the Causes of Instrument Fracture Too much apical pressure ( specially in narrow or curved canal) Used in dry canal without irrigation or lubricant Excessi

Of which main compounds is the mitochondrion structure made, Of which main ...

Of which main compounds is the mitochondrion structure made? Mitochondria are organelles delimited by two lipid membranes. The inner membrane invaginates to the interior of the

Cell-cycle controls, • Cancer cells do not respond normally to the body's c...

• Cancer cells do not respond normally to the body's control mechanism. o They divide excessively and invade other tissues. o If left unchecked, they can kill the organism. •

Can the heat capacity of water be taken small or large, Q. Can the heat cap...

Q. Can the heat capacity of water be taken small or large ? What is the biological importance of that characteristic? Ans. From Thermology it is define that the quantit

What is palliative outflow patch, What is Palliative Outflow Patch ? Br...

What is Palliative Outflow Patch ? Brock described closed pulmonary valvotomy and infundibular resection using a punch on a beating heart. When both pulmonary arteries are not

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