Pulmonary ventilation, Biology

Assignment Help:

Pulmonary Ventilation:
Pulmonary ventilation is the process by which gasses flow between the atmosphere and lung alveoli. Air moves into the  lungs when air pressure  inside the lungs is less than  the  air pressure in the atmosphere and out of  the lungs when  the pressure inside the lungs is greater than the atmosphere pressure. Breathing  in  is called inhalation or inspiration. Just before each inhalation air pressure inside the  alveoli is equal to the atmospheric pressures, 760 rnmHg,  and the intrapleural pressure is 756 mmHg. With  inspiration, the cavity of the thorax is enlarged as external intercostals muscles  and the diaphragm contract causing a decrease in  the  intrapleural pressure to about 754 mmHg. The parietal pleura lining the cavity is pulled outward in all direction and the visceral pleura and lungs are pulled along with  it. As  the  lung volume increases in this way  the pressure inside the lungs i.e.  760 mmHg drops to 758 mmHg. Thus a pressure difference  is established between the atmosphere and alveoli and air flows into the  lungs from the atmosphere. Breathing out or exhalation (expiration) starts when the  inspiratory muscles and diaphragm relaxes,  the dome of the diaphragm moves up, the ribs are depressed leading  to decrease in the  lung volume and increase in  the lung pressure (763 rnm Hg). Air flows out form the area of higher pressure to the area of lower pressure  in  the atmosphere. The elastic recoil  of the chest wall and the lungs is due to  the recoil of elastic fibers and the inward pull of surface tension due to  the alveolar fluid. A thin  layer of alveolar fluid coats the  surface of the alveoli and exerts a  force known as surface tension. Exhalation is a passive process while inhalation or  inspiration  is an active process.

 


Related Discussions:- Pulmonary ventilation

What is phylum porifera in classification of the animal king, What is Phylu...

What is Phylum Porifera in Classification of the Animal King? Sponges are the simplest form of animals. Their bodies are not organized in any specific pattern other than masses

Describe the complex spatial patterns of biodiversity, Q. Describe the comp...

Q. Describe the complex spatial patterns of biodiversity? To describe the complex spatial patterns of biodiversity, ecologists and biogeographers have found it useful to expres

Water soluble vitamins, Water Soluble Vitamins B-vitamins are abundant...

Water Soluble Vitamins B-vitamins are abundant in milk and other feeds. B-vitamins are synthesized by rumen microorganisms, beginning soon after a young animal begins feeding.

What is deoxynivalenol, Q. What is Deoxynivalenol? Deoxynivalenol (DON)...

Q. What is Deoxynivalenol? Deoxynivalenol (DON) is a far more common, but much less toxic, trichothecene and is produced by species such as F. graminearum and F. culmorum. LD

Congenital heart diseases, Congenital Heart Diseases   Congenital heart...

Congenital Heart Diseases   Congenital heart diseases are classified in many ways. One set of classification is cyanotic and acynotic conditions. Morphological classification

Admission information - nursing, Admission Information   The physician ...

Admission Information   The physician and nurses are the primary source of facts concerning the purpose of therapeutic plan and expected outcome of hospitalization. The informa

Explain about cold preservation - methods of food processing, Explain about...

Explain about Cold Preservation - methods of food processing? The metabolism of a living tissue is a function of the temperature of the environment. Low temperatures are used t

Why are we not inundated with bacterial infections, We are told that every ...

We are told that every surface we touch is teeming with bacterial cells, and bacteria are found in the pools we swim in, the water we wash with, and on the hands of friends. Why ar

X and y chromosomes determine only sex characteristics, Do the genes of the...

Do the genes of the X and Y chromosomes determine only sex characteristics? Moreover sex genes the sex chromosomes have also autosomal genes, genes that codify several proteins

Nursing management of rheumatic fever, Nursing Management The overall ...

Nursing Management The overall goals are that patient with RH fever will resume daily activities without Joint pain, reduce the risk of residual cardiac disease, and plan a

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