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

Should human gene therapy be continued, Debate over ethics of using gene th...

Debate over ethics of using gene therapy for treating human beings started since the discovery of recombinant DNA technology. The mere fact that it involves the alteration of DNA w

Life cycle of filarial worm, Life cycle of Filarial worm Filariasis : ...

Life cycle of Filarial worm Filariasis : It is popularly known as elephantiasis. It is caused by a nematode parasite, wuchereria bancrofti, and W.Malayi. Parasite : Wucher

Reroduction, describe and compare reproduction in all the kingdoms except k...

describe and compare reproduction in all the kingdoms except kingdom animalia

Define transport proteins in plasma, Define Transport Proteins in Plasma? ...

Define Transport Proteins in Plasma? Transport proteins, embedded in lipid membranes, make easy the import of nutrients into cells or the release of toxic products into the sur

What is bidirectional glenn without cardio pulmonary bypass, What is Bidire...

What is Bidirectional Glenn (BDG) without Cardio Pulmonary Bypass Surgical approach is through median sternotomy. If there is only a single superior vena cava some surgeons pre

Nutrition of embryo sac, Nutrition of Embryo Sac The morphology of th...

Nutrition of Embryo Sac The morphology of the ovule suggests that the chalazal end is the main route for the entry of nutrients. The funicular vascular supply ends at the bas

Define blood pressure, Blood Pressure Blood pressure may be defined as ...

Blood Pressure Blood pressure may be defined as the force or pressure which the blood exerts on the walls of the artery. Blood pressure varies with the age of the individual. B

Human imapct on the environment, list the long-term and short-term effects ...

list the long-term and short-term effects of forest destruction (a)on hillsides,(b)in the tropics?

What are some examples of parasitism, What are some examples of parasitism?...

What are some examples of parasitism? Classical instances are the parasites of humans (host), as the trypanosome that causes Chagas' disease, the HIV virus (AIDS), the bacteria

Where letters represent genetic markers and black dot, Two homologous human...

Two homologous human chromosomes have the following structure: where the letters represent genetic markers and the black dot represents the centromere. 1. Diagram the two chromosom

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