Explain the intercostal muscles, Science

Assignment Help:

Explain the Intercostal Muscles

Look at Figure Can you spot the intercostal muscles?

Yes, there are 11 pairs of intercostal muscles. The intercoastal muscles are the muscles between the ribs which contract during inspiration to increase the volume of the chest cavity. They are located in the spaces between the ribs. They are arranged in two layers called the external intercostal muscles and the internal intercostal muscles.

2339_The intercostal muscles.png

1. The external intercostal muscle fibres extend in a downward and forward direction from the lower border of the rib above to the upper border of the rib below.

2. The internal intercostal muscle fibres extend in a downward and backward direction  from  the lower border of the rib above  to the upper border of the rib below. They cross the external intercostal muscle fibres at right angles. The intercostal muscles are stimulated to contract by intercostal nerves.

During inspiration, the intercostal muscles contract. They move upwards and outwards causing enlargement of the thoracic cavity as shown in the Figure.

During expiration, the volume of thoracic cavity is decreased by relaxation of diaphragm and intercostal muscles which results m increase in thoracic pressure and pressure of lungs. As a result, air is expired from lungs to the atmosphere.


Related Discussions:- Explain the intercostal muscles

Explain the discovery of cell, Explain the Discovery of Cell Let us stu...

Explain the Discovery of Cell Let us study here about the scientists who played a pioneer role in discovering the basic component of any living organism -the cell. Robert Hooke

Calculate the specimen of carbon 14, Carbon l4 with a half-life of 5,568 ye...

Carbon l4 with a half-life of 5,568 years is used to date a sample of wood. Sample has l/8 the carbon l4 contained in a living tree of same species. Approximately how old is specim

Intrusion into the water cycle, Intrusion into the Water Cycle: Water m...

Intrusion into the Water Cycle: Water management is one of  the leading concerns of man  today. The natural water cycle has not been able to compensate for the effects of human

Solutions, ht are the examples oof a solution and its characteristics?

ht are the examples oof a solution and its characteristics?

Reproduction, How does the intercourse work?

How does the intercourse work?

How to calculate the student t test, How to calculate the student t test st...

How to calculate the student t test step by step when the mean of heart rate at 1 minute is 5.0,17.2,22.9,8.3,10,76.5,70,19.7 and for breathing rate it is 22.2,28.5,20,12.5,20,92,

Water borne diseases, Water Borne Diseases: Diseases like cholera and t...

Water Borne Diseases: Diseases like cholera and typhoid, as well as diarrhoea and dysentery,  are spread through water. Germs of  these diseases multiply in the gut of  the inf

Explain idiopathic thrombocytopenic purpura, Explain Idiopathic Thrombocyto...

Explain Idiopathic Thrombocytopenic Purpura "Thrombocytopenic" means the blood doesn't comprise adequate platelets. "Purpura" means a person has excessive bruising. You may als

Ground depressions in areas of karst topography, Ground depressions in area...

Ground depressions in areas of Karst topography are called: Sinkholes

It is estimated that the temperature of the earths core is, It is estimated...

It is estimated that the temperature of the Earths core is: as hot as the surface of the sun

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