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

State the study of linked genes, Why is drosophila a convenient animal for ...

Why is drosophila a convenient animal for the study of linked genes? The fruit fly drosophila is suitable for the study of Genetics because it shows many distinct traits but on

Define the visual accommodation, Q. What is visual accommodation? Visua...

Q. What is visual accommodation? Visual accommodation is the phenomenon of varying the curvature of the crystalline lens to make possible the difference of its refractivity to

Importance of mitosis, Equal Distribution of Hereditary Material: In mit...

Equal Distribution of Hereditary Material: In mitosis the heredity material is equally distributed in the daughter cell. 2.No Change in Genetic Information: As there is no

Define general characters and classification of arthropoda, Define General ...

Define General Characters and Classification of Arthropoda? These are metamerically segmented animals with an exoskeleton of cuticle. Scliizocoelic coelom is much reduced and is

Cell, Ask question #Minimum cell theory 100 words accepted#

Ask question #Minimum cell theory 100 words accepted#

Quaternary structure of protein, Quaternary Structure (4 o Structure)....

Quaternary Structure (4 o Structure). Globular in structure. When two or more than two molecules of protein of tertiary structure are connected to each other through

Explain dna binding domains, Helix-turn-helix This  motif  have  of  tw...

Helix-turn-helix This  motif  have  of  two    -helices  divided  by  a  short  (four-amino   acid) peptide  sequence  which  forms  a   -turn that shown in above figure.  When

Write a short note on muscular system, Write a short note on muscular syste...

Write a short note on muscular system? The muscular system provides mobility and support to the body. There are three types of muscle tissue: skeletal, smooth, and cardiac. Th

Are there ribosomes in a plant cell, Are there ribosomes in a plant cell? ...

Are there ribosomes in a plant cell? Yes, in fact there are ribosomes in both plant and animal cells. That is right. Ribosomes are the site of synthesis of polypeptide chain

Falling death rate, State the changes in society which could contribute to ...

State the changes in society which could contribute to a falling death rate. The changes in society which could contribute to a falling death rate are:  (i) improvements in

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