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

Whet is transferase, Transferase:- These  are the  enzymes (code EC  2)...

Transferase:- These  are the  enzymes (code EC  2) which  catalyze the transfer of a group, e.g.  a methyl or glycosyl group, from one compound to another. In many cases, the d

Decline os science, explain the factors that led to the decline of science ...

explain the factors that led to the decline of science in europe during iron agen..

Heat transfer, what are the condition necessary for heat transfer to occur?...

what are the condition necessary for heat transfer to occur?

Define protein hormone and steroid hormone, Define Protein Hormone and Ster...

Define Protein Hormone and Steroid Hormone Further, hormones are of two different chemical types - protein hormone and steroid hormone. Most of the hormones belong to the categ

Scientist, who is the first scientist

who is the first scientist

Dissecting simple flowers, Dissecting simple flowers Label each of five...

Dissecting simple flowers Label each of five cards or pieces of White paper with one of the following words: stamens, pistil, petals,sepals,  receptacle .  Dissect a flower ca

Advantages of water in chemical weathering, Advantages of water in chemical...

Advantages of water in chemical weathering Water is an essential factor of chemical weathering  and when it contains dissolved salts and acids it is all the more effective. It

Experiment to show where air may be found, TO SHOW WHERE AIR MAY BE FOUND ...

TO SHOW WHERE AIR MAY BE FOUND 1) Plunge a narrow-necked bottle, mouth down into ajar of water. Slowly tip the mouth of the bottle in the direction of  the surface of the water

Making a housing box for weather instruments, Making a housing box for weat...

Making a housing box for weather instruments Some of your weather instruments must be uncovered to the weather. Between these are the wind vane, the wind speed indicator and th

Cell theory, Ask question #Minimumwhat is that definition for cell theory? ...

Ask question #Minimumwhat is that definition for cell theory? 100 words accepted#

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