Chapter 5 System 5 Nervous System Flashcards
Nerve fibers
Projections from the body of the nerve cell that carry nervous impulses
Dendrites
Connect with other neurons to receive information
Axon
Conducts impulses away from the cell body
Synapse
The junction where nerve signals jump from one nerve to another
Neurotransmitter
Is a chemical that sends a nerve signal across a synapse
Sensory neuron
Carries impulses from sense organs to the brain
Motor neuron
Carries nerve impulses from the brain to the effectors
Interneuron
Carries impulses from one neuron to another
Myelin sheath
Covers the axons of most nerves.
Made of fatty Schwann cells.
Insulates the nerve and aids in the conduction of the nerve impulse.
Neurons have the ability to react to certain stimuli (____) and to transmit an impulse generated by that stimulus over a distance or to another neuron (____).
Irritability
Conduct ability
Functionally, what are the three types of neurons?
Sensory / afferent neurons
Motor / efferent neurons
Interneurons / internuncial neurons
Sensory / afferent neurons
Sensations of touch, cold, heat, sight, hearing, taste, or pain are carried as impulses to the brain
Motor / efferent neuron
Carry nerve impulses from the brain to the effectors (the muscles or glands they control).
Interneurons / internuncial neurons
Located in the brain and spinal cord.
Carries impulses from one neuron to another.
Transmit and direct impulses from one place in the spinal cord or brain to another
Nerves
Are bundles of fibers held together by connective tissue that originate in the brain and spinal cord and distribute branches all over the body
Afferent nerves
Carry impulses toward the spinal cord or brain
Central nervous system
Consists of the brain and spinal cord
Meninges
A special connective tissue membrane that covers the CNS incased by bone
Meningitis
Is an acute inflammation of the pia mater and arachnoid mater around the brain and spinal cord
The three layers to meninges
Dura mater -outer -tough mother
Arachnoid mater -middle -spider layer
Pia mater - innermost -delicate mother
The primary function of the nervous system is to…
Collect a multitude of sensory information;
Process, interpret, and integrate that information;
Initiate appropriate responses throughout the body
The nervous system is composed of…
the brain, spinal cord, and peripheral nerves
Cerebrospinal fluid
Flows through and around the brain and spinal cord to nourish and protect them.
Main function is to protect the CNS by acting as a shock absorber for the delicate tissue
A clear fluid derived from the blood and secreted into the inner cavities or ventricles of the brain
The brain
The principal nerve center
Body’s largest and most complex nerve tissue
Containing in excess of 10 billion neurons and innumerable nerve fibers
Located in and protected by the cranium
Controls sensations, muscles, glandular activity, power to think and feel emotion