Two Minutes of Anatomy: Myelin Sheath скачать в хорошем качестве

Two Minutes of Anatomy: Myelin Sheath

Myelin Sheath Most axons and long dendrites are coated with a protective covering called myelin. Myelin is a membrane that acts as an electrical insulator to increase the speed of conduction of impulses. Myelin does not cover the neurite completely but leaves gaps called nodes of Ranvier. In the central nervous system (CNS), myelin derives from glial cells called oligodendrocyte. Each oligodendrocyte forms multiple sheaths (up to 30 or more) around different axons In the peripheral nervous system (PNS), the source of myelin is specialized cells called Schwann cells. Each Schwann cell creates a single myelin sheath around a single axon. An axon wrapped in myelin sheath is said to be myelinated fibers, while axons not wrapped in myelin are called non-myelinated or demyelinated fibers. Nerves Primary function of nerves is to send information throughout the body via electrochemical signals. Nerves classify into three functional categories: sensory neurons, motor neurons, and interneurons. Sensory neurons receive and interpret sensory stimuli, motor neurons relay messages to muscles or glands, and interneurons transmit signals between other neurons. Nerve fibers that send information from sensory neurons to the central nervous system are termed afferent nerve fibers, while nerve fibers that carry information away from the central nervous system, such as the motor neurons to the muscles, are termed efferent nerve fibers. The sensory receptors are specialized regions or structures of the sensory neurons responsible for detecting senses and performing functions throughout the body. These receptors respond to changes in the environment by converting chemical or mechanical energy into action potentials to be transmitted towards the central nervous system. Different types of stimulus receptors mediate each of the five basic human senses (sight, hearing, smell, taste, and touch). There are many other types of receptors, including chemoreceptors, photoreceptors, baroreceptors, and proprioceptors, which detect chemicals, light, pressure, and movement, respectively. In the central nervous system, the myelinated fibers have the collective name of white matter, and the nonmyelinated fibers are collectively known as gray matter as they look white and gray respectively. References Physiology, Nerve https://www.ncbi.nlm.nih.gov/books/NB... Histology, Myelin https://www.ncbi.nlm.nih.gov/books/NB... Myelination https://www.sciencedirect.com/science... ***Disclaimer: Viewing this video does not take the place of seeing a medical professional, receiving proper training in the medical profession or working with a fitness professional. Please visit a medical professional for evaluation, diagnosis & treatment. Please work with a fitness professional to learn proper exercise technique & to develop a proper training program. Never perform an exercise that elicits or intensifies symptoms. If an exercise elicits or intensifies symptoms, stop immediately and use a viable substitute. Please receive proper medical training before attempting these medical procedures. Dr Donald A Ozello DC of Championship Chiropractic in Las Vegas, NV Web Site: http://www.championshipchiropractic.com/ Blog: https://www.championshipchiropractic.... Twitter:   / drdozellodc   Facebook:   / championship-chiropractic-280141628688300   LinkedIn:   / dr-donald-a-ozello-dc-716b3233   YouTube:    / drdozellodc   "Running: Maximize Performance & Minimize Injuries" https://www.amazon.com/Running-Perfor...