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

Determine how ion exchange data is helpful, Determine how ion exchange data...

Determine how ion exchange data is helpful The ion exchange data is helpful   ·  in soil management,   ·  indicating nutrient storage capacity of soil,    ·  prediction of s

Housing conditions for environmen, Housing: Housing is an  important co...

Housing: Housing is an  important component of healthy environment. Probably you are aware that housing conditions for the vast majority of people in  India are not up to the s

Define albumin in the urine, Define Albumin in the Urine Albumin in the...

Define Albumin in the Urine Albumin in the urine generally means leaking of the plasma albumin through the inflamed renal glomerulus (glomerulonephritis). It may also be presen

Checking breathing and pulse for unconscious casualties, Checking Breathing...

Checking Breathing and Pulse : Before attempting to resuscitate a casualty, it is essential that you check his/her breathing rate and pulse. You can cause problems if you attempt

Define the both macronutrient and micronutrient, Define the both macronutri...

Define the both macronutrientand micronutrient. An element necessary in large amounts (usually > 50 mg/kg in the plant) for the growth of plant is called a macronutrient and in

Science Fair Project, I need help finishing my science fair project, can yo...

I need help finishing my science fair project, can you help me?

Disposal of unserviceable and obsolete items, Disposal of Unserviceable and...

Disposal of Unserviceable and Obsolete Items : Every institution may have evolved its own procedure for the same. Generally the following procedure is used for the disposal of uns

Explain the small intestine, Explain the Small Intestine The small inte...

Explain the Small Intestine The small intestine is continuous with the stomach at the pyloric sphincter and leads into the large intestine at the ileocdic valve.  It is about 2

Science, In the following table state how gymnosperms are adapted for livin...

In the following table state how gymnosperms are adapted for living on land with respects to each of the following aspects Aspect Adaptation for living on land Alternation of Gener

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