--%>
Assignment Help - homework help

Motor activity of left side of body or right side of body

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

E

Expert

Verified

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

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

Motor fibers which descend from superior motor neurons to inferior motor neurons of spinal cord form the pyramidal tract. Injuries in this tract, for illustration, caused by the spinal sections or by central or spinal tumors might lead to the paraplegia and tetraplegia.

   Related Questions in Biology

  • Q : What is Management Development

    Management Development: It is the aspect of organizational development which covers assessment and recruitment of executive level employees and trains them in leadership to furnish them for higher positions. This process usually comprises development

    		•
  • Q : Difficulty of coordination Difficulty

    Difficulty of coordination Large business enterprises consist of a number of a department such a production, sales purchase . Finance these department find it hard t

    		•
  • Q : Characterization of nervous

    How is nervous system characterized in beings of phylum Annelida? How can one compare cephalization in the annelids to cephalization in platyhelminthes and nematodes?

    		•
  • Q : Importance of leadership Importance of

    Importance of leadership The following importance of leadership is prescribed as followings point: Facilitating change:

    		•
  • Q : Total fertility rate and Zero

    Briefly define the terms total fertility rate and Zero population Growth rate?

    		•
  • Q : Aspects of DMAIC Discuss the aspects of

    Discuss the aspects of DMAIC and clarify why they are important or helpful to managing Quality in an organization?

    		•
  • Q : Explain the penetration the male gamete

    Explain the penetration the male gamete to the egg cell? How does the female gamete defend itself from the entry of more gametes after the entry of the first sperm cell?

    		•
  • Q : What is Marketing Strategy Marketing

    Marketing Strategy: During the initial stages of assessing the opportunities for us in this business of supply of packed lunch boxes, we had only a sketch idea of our marketing strategy. Now that we have decided to enter the business, we want to put a

    		•
  • Q : Vitamins taken in night or at morning

    Should I take the vitamins in the night or at morning?

    		•
  • Q : Vitamins which make up B complex Write

    Write down the vitamins which make up B complex? Which problems does the scarcity of these vitamins cause?

    		•