Basics
The nervous system is made of three main structures, what are they?
The brain, spinal cord, and the nerves
The __________ are where messages are received in neurons.
Dendrites
What is a reflex?
A rapid, automatic response that bypasses the brain.
A nerve __________ begins at the cell body, travels along the axon, and passes to another neuron or effector at the axon terminal.
Impulse
The nervous system is broken up into two main parts: the __________ nervous system (which contains the brain and spinal cord) and the __________ nervous system (which contains the sensory organs and nerves).
Central; peripheral
The cell body (aka __________) of a neuron is where the nucleus is housed.
Soma
__________ neurons transmit signals between sensory and motor neurons.
Interneurons
An impulse is also called an __________ __________. This is an electrochemical event that is created by a sudden change in ion concentrations on either side of the cell membrane.
Action potential
The three principle functions of the nervous system are 1) sensory input (receive information); 2) integration (processing); and 3) __________ output (responding).
Motor
The __________ is where the impulse moves through the neuron until it reaches the terminals.
Axon
Afferent neurons (aka __________ neurons) transmit signals from receptors to the CNS.
During an action potential, the balance of positive and negative ions changes, this causes the neuron's cell membrane to become briefly __________.
Depolarized
What are the three main types of neurons in the nervous system?
Sensory neurons, interneurons, and motor neurons.
The __________ __________ covers the axon and acts as an insulator to ensure correct transmission of impulses.
Myelin sheath
Motor neurons (aka __________ neurons) transmit signals from CNS to effectors (glands and muscles).
Efferent
The __________ rule states that the action potentials occur fully or not at all. This means that the size of the action potential does not change, only the frequency of action potentials changes.
All or none
What do glial cells do?
They provide support for neurons; remember there are 10 times as many glial cells as neurons in the nervous system!
The __________ __________ is where the impulse stops, and then neurotransmitters are released across a cleft to the neurons receiving the messages.
Synaptic bulb (or just the "synapse")
Describe the steps in the nerve pathway.
Sensory receptor > Sensory neuron > Interneuron > Motor neuron > Effector
The electrical signal of the action potential is not actually what is passed from neuron to neuron - the electrical signal must be changed into a chemical messenger called __________.
Neurotransmitters (You should know and be able to discuss IN DETAIL one of the 5 neurotransmitters on the slides presentation for your exam!)