Neuroscience Flashcards
What are neurons?
Cells in the nervous system that communicate with one another to perform information processing tasks
What are the three main parts of a neuron?
Dendrites, cell body, axon
What is another name for the cell body?
Soma
What is the function of the cell body?
To coordinate the information-processing tasks and keep the cell alive
What does the cell body contain?
Nucleus
What is the function of dendrites?
To receive information from other neurons and relay it to the cell body
What is the function of the axon?
To transmit information to other neurons, muscles or glands
What is the axon covered by?
Myelin sheath
What is the function of the myelin sheath?
To insulate the axon, thereby increasing efficiency of signal transmission
What is the myelin sheath made of?
Glial cells
What are glial cells?
Cells that support the functionality of neurons
How do glial cells support functionality of neurons?
Provide physical support, supply nutrients and enhance neuronal communication
What is a synapse?
Junction or region between axon of one neuron and dendrites/cell body of another
How many synapses is an adult thought to have?
Between 100 and 500 trillion
What type of signal is transmitted across a synapse?
Chemical
What are the three types of neuron?
Sensory, motor, interneuron
What is the function of a sensory neuron?
To receive information from the external world and convey it to the brain via the spinal cord
What is the function of a motor neuron?
To carry signals from the spinal cord to the muscles to produce movement
What is the function of an interneuron?
To connect sensory neurons, motor neurons, or other interneurons
What are three types of neuron structure?
Purkinje, Pyramidal, Bipolar
What is significant about Purkinje neurons?
Elaborate tree-like assemblage of dendrites
Example of Purkinje neuron
Purkinje cells of cerebellum
What is significant about Pyramidal neurons?
Triangular cell body and a single, long dendrite with many smaller dendrites
Example of Pyramidal neuron
Hippocampal pyramidal cell
What is significant about Bipolar neurons?
A few dendrites and a single axon
What type of signal is transmitted along a neuron?
Electrical
In what direction does the electrical signal travel along the neuron?
Dendrite - cell body - axon
What is resting potential?
The difference in electric charge between the inside and outside of a neuron’s cell membrane
What causes resting potential?
K+ ion concentration
What is action potential?
An electric signal/impulse that is conducted along the length of a neuron’s axon to the synapse
What causes action potential?
Opening of sodium channels and closing of potassium channels, allowing Na+ ions to flow inside the axon
What happens when action potential reaches its maximum?
Sodium channels close and potassium channels open, returning neuron to resting potential
What are breaks in the myelin sheath called?
Nodes of Ranvier
What happens to the electric signal when it passes along a myelinated axon?
Salatory conduction