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

Function of the secretions of the seminal vesicle, Q. What is the function ...

Q. What is the function of the secretions of the seminal vesicle, prostate and bulbourethral glands in reproduction? These secretions along with sperm cells from the testicles

Determine the prosthodontic considerations, Prosthodontic considerations ...

Prosthodontic considerations In order to achieve good results, understated features should always be examinated. 1. Smile Line: A high smile line increases the esthetic

Define the figure of 8 and mattress suturing techniques, Define The figure ...

Define The figure of 8 and Mattress suturing techniques The figure of 8:  is placed similarly to the simple loop on the buccal aspect; however, on the lingual aspect, the needl

Almost bacteria are anaerobic, Most bacteria are anaerobic. If a bacterium ...

Most bacteria are anaerobic. If a bacterium were to produce the same amount of ATP within a minute as a cell extracted from your skeletal muscle, what would that bacterium have to

Prozoan, classifcation of protozoans

classifcation of protozoans

Importance of research in nursing, Importance of Research in Nursing: ...

Importance of Research in Nursing: It is  the responsibility of the nursing profession  to discover, verify, structure and restructure the professional knowledge through  syst

Explain the functional properties of proteins, Functional properties of pro...

Functional properties of proteins These are those physico-chemical properties that enable the proteins to contribute to the desirable characteristics of the food Potential f

Explain the term ageing, Explain the term Ageing? Ageing in human being...

Explain the term Ageing? Ageing in human being is of a multifunctional origin and there is a programmed senescence (ageing) of the cells in the body. The genetic make-up of an

Primary tubercle, Primary  Tubercle  (Ghon Tubercle): When  an  indiv...

Primary  Tubercle  (Ghon Tubercle): When  an  individual with  no  previous exposure  to  tuberclosis inhale a sufficient number of  tubercle bacilli into the alveoli, tubercu

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