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

Define glycogen , A glycogen molecule having entirely of glucose uni...

A glycogen molecule having entirely of glucose units, many of that are linked in long chains through α1-4 bonds.  Furthermore,  every  10  units  or  so,  the  chain  is branched

Illustrate the diabetic contract of the eye, Illustrate the diabetic contra...

Illustrate the diabetic contract of the eye? Diabetic Cataract: 1) Sorbitol Aldose Pathway: In patients with diabetes, there is increase in sugar alcohol which results in

Amino acids, Amino acids are the subunits ( or the monomers) from which pr...

Amino acids are the subunits ( or the monomers) from which proteins (polymers) are assembled. Each amino acid comprises of an amino functional group, and a carboxyl acid group, an

Use of toxic amino acids, Q. Explain Use of Toxic amino acids? Lathyru...

Q. Explain Use of Toxic amino acids? Lathyrus sativus (kesari dhal) seeds contain toxic amino acid beta-oxalyl aminoalanine (BOAA), is considered to be responsible

Define drug effects on food intake - anorexic effect, Define Drug Effects o...

Define Drug Effects on Food Intake - Anorexic Effect? Have an anorexic effect, either as a direct effect of the drug on appetite e.g., some antibiotics or because of side-effec

Investigation of aortic regurgitation by electrocardiogram, Q. Investigatio...

Q. Investigation of aortic regurgitation by Electrocardiogram? Electrocardiogram shows left ventricular dominance with voltage criteria for left ventricular hypertrophy. In mod

Explain about bioactive materials, Explain about Bioactive materials Bi...

Explain about Bioactive materials Bioactive materials: Certain glasses, ceramics, and glass-ceramics that contain oxides of silicon, sodium, calcium and phosphorus (SiO 2 , Na

Define titrimetric method - 2, Define Titrimetric Method - 2, 6 Dichlorophe...

Define Titrimetric Method - 2, 6 Dichlorophenol Indophenol Method? The titrimetric method is a redox titration method which depends on the reduction of the blue dye 2,6 dichlor

What is the prothallus of pteridophytes, Q. What is the prothallus of pteri...

Q. What is the prothallus of pteridophytes? The gametophyte develops by mitosis from a spore and Prothallus is the pteridophyte gametophyte (the haploid individual that forms g

Genetics., Ask Two true-breeding pea plants were crossed. One parent is rou...

Ask Two true-breeding pea plants were crossed. One parent is round, terminal, violet, constricted, while the other expresses the respective contrasting phenotypes of wrinkled, axia

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