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

Science, hi can you help me on my science

hi can you help me on my science

Demographic variables, There are no demographic variables that alter the in...

There are no demographic variables that alter the interpretation of the test results. Test-taking Behaviors Mr. X did not omit any items (?=0) and endorsed the items consiste

Functional unit of the nervous system-neuron, Functional unit of the nervou...

Functional unit of the nervous system-neuron: The human brain is composed of more than one hundred billion (100,000,000,000  or 1011) cells called  'neurons'. This number which

Holozoic and holophytic, difference between holozoic mode of feeding holoph...

difference between holozoic mode of feeding holophytic

Explain the phagocytosis, Explain the Phagocytosis Phagocytosis include...

Explain the Phagocytosis Phagocytosis includes the ingestion of particulate material including complete pathogenic microorganisms. The plasma membrane expands around the partic

Explain the urinary bladder, Explain the Urinary Bladder The urinary bl...

Explain the Urinary Bladder The urinary bladder is a sac, which acts as a reservoir for urine. You would realize that the size and position of the urinary bladder varies depend

Define the post central area of the cerebrum, Define the post central area ...

Define the post central area of the Cerebrum The post central area is behind the central sulcus. Here, the sensations of pain, temperature, pressure and touch, knowledge of mus

Disposal of microbial cultures, DISPOSAL OF MICROBIAL CULTURES: After the ...

DISPOSAL OF MICROBIAL CULTURES: After the study is finished microbial cultures should not be left in the laboratory or taken out of the laboratory alive because availability of th

What are the advantages of acid soils, What are the Advantages of Acid Soil...

What are the Advantages of Acid Soils The acid soils, formed by any of the above processes, behave as very strong acids so much so that pH is quite low even in partial convers

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