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

Periodic table, How did it change from Mendeleev to Mosely?

How did it change from Mendeleev to Mosely?

An experiment with a bottle and cork, An experiment with a bottle and cork ...

An experiment with a bottle and cork Tightly close a liitle bottle with a cork or rubber stopper. Place the bottle in the receiver and remove some of the air with the pump.

Viruses, diseases caused by viruses?

diseases caused by viruses?

The need for reporting accidents, The Need for Reporting Accidents : All a...

The Need for Reporting Accidents : All accidents (no matter how trivial) and, dangerous near misses should be recorded. The recording of accidents ensures that all injuries are tr

Water-mill in golden era, Water-mill in Golden era: The water-mills wer...

Water-mill in Golden era: The water-mills were also invented in  the classical period. But they came to be widely used only in  the Middle Ages. The wind-mills and water-mills

Ecology, what are relations of ecology with other sciences?

what are relations of ecology with other sciences?

Experiments with man in space, Experiments with man in space: We have a...

Experiments with man in space: We have already discussed  the usefulness of space  flights in Blocks 3&4. One is able to make astronomical observations from satellites; get met

Earth science, alternative naturalenergyresourcebasedo on undergroundhot wa...

alternative naturalenergyresourcebasedo on undergroundhot water source

Define aquaculture, QUESTION 1 (a) Define aquaculture (b) What is th...

QUESTION 1 (a) Define aquaculture (b) What is the importance of aquaculture? (c) Name 4 aquaculture species cultured in Mauritius. (d) List down the criteria for selec

Understanding manufacturing methods and material choices, This project is i...

This project is intended to stimulate discussion during the lectures/tutorials on the choices of materials and manufacturing issues related to materials. We will discuss our "objec

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