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

How is the parathyroid hormone secretion regulated, How is the parathyroid ...

How is the parathyroid hormone secretion regulated? It is simple. An increase in parathyroid hormone causes an increase in calcium absorption from the intestine and renal tubul

State the pipette method of soil, State the Pipette Method of soil The ...

State the Pipette Method of soil The   sieve analysis, though is a true particle size analysis, is  unable to separate particles smaller than 20 microns. Such particles are sep

Germinating pollen grains, Germinating pollen grains Apparatus Used-Mak...

Germinating pollen grains Apparatus Used-Make a strong sugar solution and place it in a shallow dish like a saucer or Circular  Plate. Shake pollen from several Different kinds

Hypersecretion of adrenocortical hormones during childhood, Hypersecretion ...

Hypersecretion of Adrenocortical Hormones during Childhood Children suffering from hypersecretion of adrenocortical activity are described as Infant Hercules. There is too earl

Define the pre motor areas of the cerebrum, Define the Pre Motor Areas of t...

Define the Pre Motor Areas of the Cerebrum The pre motor areas too lie in the frontal lobe immediately anterior to the motor area as highlighted in the Figure. The cells are th

Animal diversity, affinities of ctenophora with platyhelminthes

affinities of ctenophora with platyhelminthes

Career query, Hello sir, This is pradeep. I have completed M.Sc Biochemist...

Hello sir, This is pradeep. I have completed M.Sc Biochemistry since then i worked as a chemist in quality control department in pharmaceutical and cosmetic companies. I have co

What are the important processed pulse products, Q. What are the important ...

Q. What are the important processed pulse products? Puffed chickpea and pea, besan, papads, pulse-based weaning foods, quick cooking dhals, and canned dry peas are the importa

How to make a devil diver (cartesian diver), How to make a devil diver (Car...

How to make a devil diver (Cartesian diver) Find a tall glass jar with a quite wide mouth. Wrap a few turns of copper wire about the thin part of the rubber bulb from a medicin

Why do dark colours absorb heat?, Question 1 Outline the risks of nuclear ...

Question 1 Outline the risks of nuclear fissions Question 2 Comment on semiconductor devices and their usage Question 3 In a total system approach, what are the various

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