Quiz 1 Flashcards
Membrane potential
The charge difference across the plasma membrane
Synapse
A junction at the end of an axon where it stimulates another cell
Myelin
A lipid sheath around a nerve fiber
Somatic sensory
Carries signals from receptors in the skin, muscles, bones, and joints
Visceral sensory
Carries signals mainly from the viscera of the thoracic and abdominal cavities
Interneurons
A neuron that is contained entirely in the central nervous system
Dendrite
Extension of a neuron that receives information from other cells
Axon
AKA nerve fiber; the portion of a nerve cell that carries nerve impulses away from the cell body
Cell body
The spherical part of a neuron that contains the nucleus
Neuroglia cells
All cells of nervous tissue except neurons
Sodium-potassium pump
An active transport mechanism in the plasma membrane that used ATP
Current
A moving stream of charged particles such as ions or electrons
Action potential
A dramatic change produced by voltage-gated ion channels in the plasma membrane
Nerve impulse
A wave of self-propagating action potentials traveling along a nerve fiber
Local potential
Produced by gated channels on the dendrites and soma
Neurotransmitter
A chemical released at the distal end of an axon that stimulates an adjacent cell
Spinal nerves
Arise from the spinal cord and supply branches to muscles below the neck
Cranial nerves
Arise from the base of the brain and innervate muscles of the head and neck
Spinal reflex
Plays vital roles in posture, motor coordination, and protective responses to pain or injury
Dermatome
Areas of skin that send signals to the brain through the spinal nerves
Sympathetic nervous system
A division of the autonomic nervous system that issues efferent fibers through the thoracic and lumbar nerves and usually exerts adrenergic effects on its target organs
Parasympathetic nervous system
A division of the autonomic nervous system that issues efferent fibers through the cranial and sacral nerves and exerts cholinergic effects on its target organs
Afferent neuron
Specialized to detect stimuli such as light, heat, pressure, and chemicals
Efferent neuron
Send signals mainly to muscle and gland cells
