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

Surgery in iron age, Surgery: Susruta-Samhita,  a.major  treatise on su...

Surgery: Susruta-Samhita,  a.major  treatise on surgery, was derived not only from exhaustive observation of symptoms of diseases  and their possible treatments but also a fair

The heart, how does the heart work?

how does the heart work?

State the chemical and physical processes of weathering, State the Chemical...

State the Chemical and Physical processes of weathering The chemical and physical processes of weathering aid each other. A rock mechanically broken into smaller pieces exposes

Explain the functions of gastric juice - antiseptic action, Explain the Fun...

Explain the Functions of Gastric Juice - Antiseptic Action Antiseptic action: Hydrochloric acid in the gastric juice acts as a barrier to the passage of certain microorganisms

Define the term - soil protozoa, Define the term - Soil protozoa These ...

Define the term - Soil protozoa These are unicellular but larger than bacteria, the size varying from a few microns to a few centimeters. The protozoa exist in all aerable soil

Atomic spectroscopy, Diagrammatically explain about the complementary natur...

Diagrammatically explain about the complementary nature of atomic absorption spectrophotometer and atomic emission spectrometry.n..

The movement of a glacier, Which is primarily involved in the movement of a...

Which is primarily involved in the movement of a glacier: gravity

What are the effects of temperature variations, What are the Effects of Tem...

What are the Effects of Temperature variations Different minerals present in the rock behave differently to the changing temperatures. The rocks expand on getting heated at day

Explain kaleidoscope brainstorming process, Question 1) What is decisio...

Question 1) What is decision making? Explain the various steps followed to observe effective decision making 2) Explain Kaleidoscope brainstorming process 3) Discuss SWOT Analy

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