NERVE IMPULSE Flashcards
Three functions of the nervous system
Sensory input, integration, motor output
Resemble neurons but are unable to conduct nerve impulses. They nourish, insulate, and protect the neuron
Neuroglia (supporting cells)
Responsible for impulse conduction. these cells are specialized to transmit messages
Neuron
True or false. Neurons can undergo mitosis.
False. Once they are damaged, they cannot be replaced
the metabolic center of the neuron
Cell body
intermediate filaments that maintain cell shape, and is made up of protein
Neurofibrils
Also known as the rough endoplasmic reticulum of the cell body
nissl bodies
shorter and finer extensions that communicates with another neuron. it conducts impulses toward the cell body
Dendrites
conduct impulses away from the cell body
Axons
gap between axon terminals and the next neuron
Synaptic cleft
Axons end with what structure?
Axon terminals
functional junction between nerves where a nerve impulse is transmitted
Synapse
ability to respond to a stimulus and convert it to a nerve impulse
Irritability
ability to transmit the impulse to other neurons, muscles, or glands
Conductivity
Kind of impulse that changes in polarity within a cell
Electrical impulse
Kind of impulse that is produced by neurotransmitter
Chemical impulse
Cellular transport that does not require ATP, it relies on concentration gradient and moves from high to low in order to achieve balance
Passive transport
Sodium-Potassium pump that requires ATP
Active transport
When the plasma membrane is inactive, it means that it is ___?
Polarized
When polarized, the major positive ion inside the cell is?
Potassium (k+)
The major positive ion outside the cell when the plasma membrane is inactive is?
Sodium (Na+)
what changes the permeability of the neuron’s membrane to sodium ions?
Stimulus
The inward rush of sodium ions causing the change the polarity is called?
Depolarization
Fibers with ___ conduct nerve impulses more quickly
Myelin sheaths
it means the nerve impulse either is propagated or not
All-or-none response
involves restoring the inside of the membrane to a negative charge and the other surface to a positive charge
Repolarization
True or false. Until repolarization is complete, a neuron cannot conduct another nerve impulse
True
An action potential is generated due to an influx of?
Sodium
When an action potential reaches the axon terminal, what channels open?
Calcium channels
Calcium enters the cell and mobilizes ___?
Vesicles
The vesicles release this chemical to change the permeability of the membrane allowing the sodium ions to enter the cell
Acetylcholine
Acetylcholine is released through what process?
Exocytosis
Calcium will bind to ___, allowing muscle contraction to happen
Myosin binding complex
type of neuron that carries impulses from the sensory receptors to the CNS
Sensory / afferent neurons
Type of neuron that carries impulses from the central nervous system to viscera and/or muscles and glands
Motor / efferent neurons
Connect sensory and motor neurons
Interneurons
rapid, predictable, and involuntary responses to stimuli
Reflexes
involuntary reflexes that stimulate the skeletal muscles.
Somatic reflexes
Regulate the activity of smooth muscles, the heart, and gland
Autonomic reflexes
Patellar (knee-jerk) reflex is an example of two-neuron or three-neuron reflex arc?
Two-neuron
Three-neuron reflex arcs consist of how many elements?
Five (receptor, sensory neuron, interneuron, motor neuron, and effector)
Reflexes occur over neural pathways called the?
Reflex arc
These neurons can be found in the cutaneous sense organs in skin
Sensory / afferent neurons
Initial conditions of sodium and potassium ions are restored using the?
Sodium-potassium pump
