Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Myelinated fibre
Axon is a relatively long process (also quite often referred to as nerve fibre) and can be considered as functionally specialised for conduction of excitation over considerable distances. In vertebrates the axons of high velocity neurons are covered by insulating sheaths of lipid containing myelin. This myelin is made up of special glial cells -the Schwann cells. The myelin covering is not continuous. There are tiny uninsulated gaps between adjacent Schwann cells. These are the-nodes of Ranvier. The myelin covering and nodes of Ranvier help accelerate the speed of conduction of impulses by a mechanism which we will discuss later. The terminal part of the axon branches, terminating into small ramifications whose tips form end knobs which synaptically contact with other nerve cells. In the end knobs are present characteristic structures called synaptic vesicles which contain and store chemical substances called neurotransmitters.
Figure: Myelinated fibre
The diversity in neuron form, however so much that is there can be many variations from the generalized description given above. For example, the nerve cells called amacrine cells found in retina contain processes without a demonstrable axon.
Action of Hormones We said earlier that hormones are released into the blood stream or extracellular fluid and therefore, reach most of the cells of the body. However, they
BRONCHOSCOPY: Bronchoscopy is the passage of lighted bronchoscope into the bronchial tree. Bronchoscopy may be performed with rigid steel of flexible fiberoptic instruments.
What are holandric genes? Holandric genes are genes situated in the nonhomologous region of the Y chromosome. Holandric genes condition phenotypes that emerge only in men as in
about it
Elaborate the term - Gill slits. Lateral opening in the wall of pharynx which allows water to enter into mouth and exit through the pharynx. This is one of the ancestral charac
NON-MUSCULA R MOVEMENT - 1 . Streaming movement - In amoeba, cyclosis is common. 2 . Pseudopodial - In leucocyte, macrophages, amoeboid movement take place
Impoundments - Lentic Ecosystems We have so far discussed natural lakes. In addition to these there are a number of lakes both small and large artificially created by man cal
Q. Relationship between Mind and Brain? In modern times, before the 20th century, the most popular interpretation of the mind-brain relationship was some version of dualism. It
Role of Private Sector in Health Care One of the biggest policy challenges for the government is to decide on the appropriate areas and a suitable policy framework for having
The evolutionary species concept which identifies a species as a "lineage (i.e. ancestor descendant sequence of population) evolving separately from others with its own unitary ro
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd