Many axons, especially the larger ones, are insulated with a myelin sheath. Write an essay on the importance of the myelin sheath, making sure to incorporate the following information:
? What kind of cells make up the myelin sheath?
? What does the myelin sheath look like?
? What are two purposes of the myelin sheath?
? What happens when a person experiences the loss of myelin?
What will be an ideal response?
Answer: A good answer will include the following key points.
? Myelin is a fatty sheath formed by glial cells.
? It occurs in segments along the axon and looks like a string of link sausages.
? Its key functions are to prevent signals in adjacent cells from interfering with each other and to speed up conduction of neural impulses.
? In individuals with multiple sclerosis, loss of myelin causes erratic nerve signals resulting in things like loss of sensation, muscle weakness or paralysis, lack of coordination, or vision problems.
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According to the law of specific nerve energies, the brain tells the difference between one sensory modality and another by ____
a. which neurotransmitter is released b. which neurons are active c. the velocity of the action potentials d. the amplitude of the action potentials
Dallas is using the rational method when, upon seeing that birds eating certain berries do not die, concludes that the berries are not poisonous
a. True b. False Indicate whether the statement is true or false
Gestalt psychologists have noted the rules in the way humans integrate bits and pieces of sensory stimulation into meaningful whole experiences. The rules are referred to as the laws of
a. bottom-up processing. c. perceptual organization. b. figure-ground perception. d. opponents process theory.
Both infants and adults may hold misconceptions about the behaviour of physical objects in the world. This is known as ______________.
a. object impermanence b. naïve physics c. personal fables d. theory of mind