Explain about cerebral hemispheres, Biology

Assignment Help:

How is it structurally explained that the motor activity of the left side of the body is controlled by the right cerebral hemisphere and the motor activity of the right side of the body is controlled by the left cerebral hemisphere?

In the cerebral hemispheres there are neurons that centrally command and control muscle movements. These neurons are known as superior motor neurons and they are located in a special gyrus of both frontal lobes called as motor gyrus (or precentral gyrus). The superior motor neurons send axons that transmit impulses to the inferior motor neurons of the spinal cord (for neck, trunk and limb movements) and to the motor nuclei of the cranial nerves (for face, eyes and mouth movements).

The fibers cross to the other side in exact areas of those axon paths. About 2/3 of the fibers that go down the spinal cord cross at the medullar level forming a structure known as pyramidal decussation. The other (1/3) of fibers descend in the same side of their original cerebral hemisphere and cross only within the spinal cord at the level where their associated motor spinal root exit. The fibers that command the inferior motor neurons of the cranial nerves cross to the other side just before the link with the nuclei of these nerves.

 


Related Discussions:- Explain about cerebral hemispheres

Symptoms of angina pectoris, Q. Symptoms of Angina Pectoris? The pain o...

Q. Symptoms of Angina Pectoris? The pain of angina is usually over the center of the chest (below the sternum) but can be felt from epigastrum to the jaw and arms. It is brough

Living fossils, LIVING FOSSILS - 1. Limulus (Ki...

LIVING FOSSILS - 1. Limulus (King crab) Arthropoda 2 . Neopelina Mollusca 3 .

Show the major human diseases caused by fungi, Q. What are the major human ...

Q. What are the major human diseases caused by fungi? The main human diseases caused by fungi are paracoccidioidomycosis, histoplasmosis, blastomycosis, coccidioidomycosis, or

What is sanitation in food service establishments, Q. What is Sanitation in...

Q. What is Sanitation in food service establishments? We start our study of this topic by first defining what is sanitation? A three-word definition of food sanitation

The eye refract the light, Which parts of the eye refract ('bend') the ligh...

Which parts of the eye refract ('bend') the light in such a way as to form an image on the retina?   The curved surface of the cornea, and the aqueous humour enclosed by it,

What is qt dispersion, Q. What is QT Dispersion? Is the difference betw...

Q. What is QT Dispersion? Is the difference between the QT interval measured from one part of the heart and the QT interval measured from another part of the heart. The QT inte

What bacterial cell structures are used to carry the genes, What bacterial ...

What bacterial cell structures are used to carry the genes intended for genetic engineering? The cells structures in bacteria which carry genes intended for genetic engineering

Chromsome, How does a person with drown syndrome obtain a third chromosome ...

How does a person with drown syndrome obtain a third chromosome 21?

What best describes the amoebas division, What best describes the amoebas d...

What best describes the amoebas division?  (1) It is a Mode of asexual account in which a one parent is involved. The amoeba cell, which is unicellular, separates into two daug

Darwins theory of natural selection, Darwins theory of natural selection is...

Darwins theory of natural selection is considered a paradigm shift--a theory that has wide-ranging effects. Describe some of the advantages that this theory offered scientists once

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