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

Biologically compounds that contain oxygen and nitrogen, Q.Name two biologi...

Q.Name two biologically important compounds that contain both oxygen and nitrogen. Two biologically important compounds that contain both oxygen and nitrogen are: (i) Amino a

Scientific method, The effect of varying the pH of the yeast solution on th...

The effect of varying the pH of the yeast solution on the functioning of an enzyme catalase

A model illustrating how an eclipse appears, A model illustrating how an ec...

A model illustrating how an eclipse appears The sun is shown by an opal electric bulb shining by a circular hole 5 cm in diameter in a piece of blackened cardboard. The corona

Explain the menopause, Explain the Menopause The cessation of menstruat...

Explain the Menopause The cessation of menstruation is menopause. Natural menopause typically occurs between 45 and 55 years of age. It is caused by changes in concentration of

Scientific chemistry used in arab, Scientific Chemistry:  The Arab doct...

Scientific Chemistry:  The Arab doctors, perfumers and metallurgists made their greatest contribution  in chemistry. This was mainly due to the fact that Arab scholars, unlike

Iron age, Iron Age: We briefly surveyed the ideas and techniques of  th...

Iron Age: We briefly surveyed the ideas and techniques of  the early human beings, and traced the roots of  science in  the primitive culture. You also read about the emergence

What is protein, Explain Protein  Protein  is  derived  from  a  Greek...

Explain Protein  Protein  is  derived  from  a  Greek word  "PROTOS"  which  means  "Pre eminent", "jht or foremost"  or  primary matter.  This  name was  suggested  by  Berzi

Introduction to hazards in biology laboratory, INTRODUCTION : In any scien...

INTRODUCTION : In any science lab you work with chemicals, gases, electrical equipments, glassware, instruments etc. In case you are working in a biology laboratory handling the p

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