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 sneezing reflex actions - respiratory process, Explain Sneezing Ref...

Explain Sneezing Reflex Actions - Respiratory Process This reflex is an involuntary, sudden, violent and audible expulsion of air through the mouth and nose. Usually irritation

Bdp, describe the factors which decide the broad area of scientific activit...

describe the factors which decide the broad area of scientific activity?

Earths magnetism, what is the cause of earth''s magnetism?

what is the cause of earth''s magnetism?

Some physical features of the atmosphere, Some Physical Features of the Atm...

Some Physical Features of the Atmosphere: i) The atmosphere is a mixture of gases. It is made up of 78.08%  nitrogen; 21% oxygen by volume. There is only 0.03%  of carbon dioxi

Explain the posterior pituitary, Explain the Posterior Pituitary The po...

Explain the Posterior Pituitary The posterior pituitary gland or neurohypophysis is located immediately behind the anterior pituitary gland, as you may have seen in Figure.

Define the ear canal, Define the Ear Canal The other part of the outer ...

Define the Ear Canal The other part of the outer ear is the ear canal. The ear canal, which conveys the sound to the eardrum, is a rather tortuous canal. It is lined with skin,

To learn the use of a carbon dioxide fire extinguisher, TO LEARN THE USE OF...

TO LEARN THE USE OF A CARBON DIOXIDE FIRE EXTINGUISHER : All chemical laboratories should be provided with carbon dioxide and or dry chemical fire extinguishers. Carbon dioxide fi

Vulvovaginitis, what is the cause and effect of vulvovginitis?

what is the cause and effect of vulvovginitis?

Determine the bravais lattice of the element, An x-ray diffractometer recor...

An x-ray diffractometer recorder chart for an element that has either the BCC or the FCC crystal structure shows diffraction peaks at the following 2θ angles: 40 0 , 58 0 , 73 0 ,

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