Chapter 11 nervous system
How does the composition of gray matter differ from white matter
Gray matter is a group of cell bodies and U myelinated fibers and white matter is composed of myelinated fibers
Neurons
Have extreme longevity and can last for a lifetime. Are Amiotic and lose ability to divide and don't replace if destroyed. High metabolic rate and require oxygen and glucose and cannot survive without a few minutes without oxygen
How does the myelin sheath of a neuron effect the speed of an impulse
Increases speed of the impulse because action potential leap from one node to the next
How does a tract differ from a nerve
Tract is a bundle of nerve fibers found in the CNS and nerve is a bundle of fibers found in PNS
Axon terminal
Communicate with other cell and sends impulses
Schwann cell
A type of supporting cell in the PNS; forms myelin sheaths and is vital to peripheral nerve fiber regeneration; forms myelin sheath
The principal way neurons communicate is by generating and propagating
Action potential/nerve impulses
Cell body or soma
Consists of a transparent spherical Nucleus surrounded by cytoplasm; major biosynthetic of a cell
Nucleus
Control center of a cell constrains genetic material
Glia cells that brace and anchor neurons to nutrient capillaries
Astrocytes
Glia cells that control the chemical environment around neurons, most importantly "mopping up" leaked potassium ions and recapturing released neurotransmitters
Astrocytes
Which glial cell is most abundant and versatile of the glial cells
Astrocytes
Which glial cells are found within CNS
Astrocytes, microglia, ependymal cells and oligodendrocytes
What is a reflex
Automatic reaction to a stimulation
How does the size of an axon affect the speed of an impulse
Bigger the fiber the faster the impulse
What is the function of the neurotransmitter known as acetylcholine
Bonds to receptor cites
Dendrite
Branching neuron process that serves as a receptive or input, region; transmits the nerve impulse toward the cell body
Which glial cell line the central cavities of the brain and spinal cord and the beating of their flagella circulates the cerebrospinal fluid that cushions the brain and spinal cord
Ependymal cells
Myelin sheath or neurilemma
Fatty insulating sheath that surrounds all but the smallest nerve fibers
What is a synapse
Functional junction or point of close contact between two neurons or between a neuron and an effector cell
Glia cells that serve to monitor health of nearby neurons and when dead neurons or microorganisms are present they transform into a special type of macrophage that phagocytizes microorganisms or neuronal debris
Microglia
Name two major types of cells that have an excitable membrane
Nerve cells and muscle cells
A transmitted action potential is also known as a
Nerve impulse
The other type of cell found in the nervous system is also called nerve cells
Neuron
Axon
Neuron process that carries impulses away from the nerve cell body; efferent process; the conduction portion of a nerve cell
The chemical substances that allow neurons to communicate with each other and send messages to The rest of the body as Called
Neurotransmitters
Glia cells that produce the myelin sheath around the nerve fibers in the CNS
Oligodendrocytes
What are the three major overlapping functions of the nervous system
Sensory input Inter junction or interneuron Motor output
Node of ranvier
Region that provides an impulse to leap
Vasodilation
Relaxation
Which glial cells are found within PNS
Satellite and Schwann cells
Glia cells that surround neuron with ganglia, but their function is still largely unknown
Satellite cells
Which glial cell form the myelin sheath around the larger nerve cells in the PNS
Schwann cells
Explain how nodes of ranvier form along an axon in the peripheral nervous system
Schwann cells wrap around axon and leaves a space between Schwann cells which is a node
Explain how sensory, motor, and interneurons differ functionally
Sensory carries impulses to CNS Motor go from neuron
Explain how an antihistamine might aid you when you have allergies
Stop active histamine
In the field of medicine does a neurologist specialize
Study of nervous system functions and its disorders
Long distance running is associated with the release of the neurotransmitters called endorphins explain why a long distance runner might experience what is called a runners high
There are natural opiate substance that inhibits pain and this mimicks the effect of morphine, heroine and meth