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

Sensor measures the current value of the controlled variable, In a properly...

In a properly functioning negative feedback system A. value of the controlled variable will always be very close to the threshold value when the system is in steady state.

Which dsdna is imprtant for dna purification, Which of the following proper...

Which of the following properties of dsDNA is imprtant for DNA purification? A. Hydrophilic B. Positively charged phosphate backbone C. Can only bind to divalent cations

How many chambers does the fish heart have, Q. How many chambers does the f...

Q. How many chambers does the fish heart have? The fish heart is a tube made of two consecutive chambers such as one ventricle and one atrium.

Planning the nursing care for dysentry, Planning the Nursing Care   1) ...

Planning the Nursing Care   1) Maintain hydration and electrolyte balance.  2) Administer accurate and adequate antibiotics drugs.  3) Prevent the spread of infection.

What is the action mechanism of the antiretroviral drugs, What is the actio...

What is the action mechanism of the antiretroviral drugs called protease inhibitors which are used against HIV infection? Protease inhibitors are some of the antiretroviral dru

What is endocrine system explain, What is Endocrine System explain ? Th...

What is Endocrine System explain ? The endocrine system consists of glands, organs that secrete hormones. Endocrine glands are tissues that produce secretions within the body,

Deficiency diseases-calcium deficiency (hypocalcicosis), Calcium  deficien...

Calcium  deficiency (hypocalcicosis) Calcium deficiency or hypocalciosis is a sporadic condition occurring in a particular group of animals causing osteodystrophy. Aetiol

Explain pseudocoelomates in classification animal kingdom, Explain Pseudoco...

Explain Pseudocoelomates in classification animal kingdom? In terms of body organization, Pseudocoelomates fall between the Acoelomates and the Coelomates. The body cavity in

What main idea, What key idea, contained in Malthus's essay on populations,...

What key idea, contained in Malthus's essay on populations, helped Darwin formulates his theory of natural selection?

What is the difference between phenotype and genotype, What is genotype? Wh...

What is genotype? What is the difference between phenotype and genotype? The Genotype is the genes, DNA nucleotide sequences contained in the chromosomes of an individual, whic

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