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

Scientist, who is the first scientist

who is the first scientist

why did the earth form with four main layers inside it, Density of the Ear...

Density of the Earth's Layers Density and gravity caused the proto-Earth to cool and settle into four distinct layers. The four layers are, from top to bottom: the crust, the

Emergence of urban societies, Emergence of Urban Societies:  The writ...

Emergence of Urban Societies:  The writings of this period also give us a picture of  the social conditions. The social structure was undergoing radical changes at this time,

The atmosphere, how many times more nitrogen then oxygen in the air

how many times more nitrogen then oxygen in the air

Explain examination of urine, Explain Examination of Urine Examination ...

Explain Examination of Urine Examination of urine is done to detect the presence of any abnormal constituent(s) and hence can be used as an important screening test for identif

Life of a star, Life of a Star: A young star is thought  to be composed...

Life of a Star: A young star is thought  to be composed largely of  hydrogen gas. Hence, the most likely place for a star to be born is in one of  the numerous clouds of hydrog

Need for safety and health regulations, NEED FOR SAFETY AND HEALTH REGULATI...

NEED FOR SAFETY AND HEALTH REGULATIONS : Accidents in work place are caused by negligence at some level. Legal control is required when individuals and organisations fail to reali

Electrochemistry, why we use mercury in the measurement of conductance usin...

why we use mercury in the measurement of conductance using wheatstone bridge principle

Method for moderately volatile liquid wastes-chemical wastes, For moderatel...

For moderately volatile liquid wastes : Spillage of moderately volatile liquids could be absorbed on sand, shovelled into bucket(s) and transported to a safe open area for evapora

Sedimentary rock, would sandstone or quartzite break easier?

would sandstone or quartzite break easier?

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