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 gynaecological morbidity, Explain the Gynaecological morbidity ...

Explain the Gynaecological morbidity Gynaecological morbidity, which covers any condition, disease or dysfunction of the reproductive system that is not related to pregnancy, a

Albanian, what is the mendeleyev

what is the mendeleyev

Explain the chemical weathering processes, Explain the Chemical Weathering ...

Explain the Chemical Weathering Processes  The chemical process of decomposition starts with the physical disintegration of rocks and minerals. In chemical weathering processes

Explain the nuclei or ganglia, Explain the Nuclei or Ganglia Deep withi...

Explain the Nuclei or Ganglia Deep within the cerebral hemispheres are groups of nerve cells called nuclei or ganglia which act as relay stations, where impulses are passed fro

Explain the urea cycle, Explain the Urea Cycle ? From our discussion a...

Explain the Urea Cycle ? From our discussion above, it is clear that the amino group of all amino acids is ultimately converted to ammonia (NH3). Ammonia is highly toxic to th

Gloves for personal protective devices, Gloves : Gloves should be worn whe...

Gloves : Gloves should be worn when transferring toxic, radioactive and carcinogenic compounds, irritants and corrosive liquids. The practice of wearing rubber gloves continuously

Explain the respiratory centre, Explain the Respiratory Centre The resp...

Explain the Respiratory Centre The respiratory centre consists of two main parts - inspiratory centre and the expiratory centre. The inspiratory centre is dominant. A reciproca

Explain enzyme immobilization, Enzyme immobilizatio:- The attachment of...

Enzyme immobilizatio:- The attachment of an enzyme to a solid matrix so  that it cannot escape but can still act on its substrate.  .

Illustrate about the colour of the soil, Illustrate about the colour of the...

Illustrate about the colour of the soil The colour of the soil gets influenced by the oxidation states of metal ions. Colours such as red, yellow and reddish brown are found u

Explain somatic mutation theory of ageing, Explain somatic mutation theory ...

Explain somatic mutation theory of ageing Random mutation makes the cells inefficient. An increase in the number of mefficient cells in an organ impairs their functioning. Rand

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