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 yawing reflex actions - respiratory pocess, Explain Yawing Reflex A...

Explain Yawing Reflex Actions - Respiratory Pocess Yawning:  It is a deep inspiration drawn through open mouth. Low oxygen tension in the blood may be the cause of yawning.

Explain the dialysis, Explain the Dialysis   By now, you must have w...

Explain the Dialysis   By now, you must have well understood the functions of kidney and the implications of abnormal kidney functioning as well. Here in this section, we sh

Laboratory safety codes, Laboratory Safety Codes: BIS has prepared the fol...

Laboratory Safety Codes: BIS has prepared the following three codes (in the form of small books) regarding laboratory safety: i) Code of safety in microbiological laboratories

Ethical issues in colorectal cancer, The hospital Human Research Ethics Com...

The hospital Human Research Ethics Committee granted approval for the study protocol. Participants provided written informed consent. All participants were all over the age of 18 a

Define haemorrhagic or blood loss anaemia, Define Haemorrhagic or Blood Los...

Define Haemorrhagic or Blood Loss Anaemia The body replaces plasma within 1-3 days after a haemorrhage, but this leaves a low concentration of red blood cells. In chronic bloo

Explain the secretion of aldosterone, Explain the Secretion of Aldosterone ...

Explain the Secretion of Aldosterone A minimal amount of ACTH is also needed for the secretion of aldosterone. The secretion of aldosterone is thus stimulated by: a d

Intrusion into the carbon cycle, Intrusion into the Carbon Cycle   In  t...

Intrusion into the Carbon Cycle   In  the carbon cycle, as long as the average amount of carbon dioxide hair and in water remains the same, a happy situation prevails. If the te

Normal limits and factor scales, Factor Scales Mr. X is not overtly ex...

Factor Scales Mr. X is not overtly expressing any form of generalized distress or negative emotionality; he is extroverted and verbally fluent (A= 39, PSYC=40, NEGE=43). Howev

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