Biological Bases of Behavior Flashcards
Neurons
Individual nerve cells made of dendrites, cell body, axon, myelin sheath, terminal buttons, neurotransmitters, and the synapse.
Myelin sheath
A fatty covering around the axon of some neurons that speeds neural impulses.
Axon
Wire like structure ending in the terminal buttons that extends from the cell body.
Terminal buttons
The branched end of the axon that contains neurotransmitters.
Neurotransmitters
Chemicals contained in terminal buttons that enable neurons to communicate. Neurotransmitters fit into receptor sites in the dendrites of neurons.
Synapse
The space between the terminal buttons of one neuron and the dendrites of the next neuron.
Cell body
Also known as the soma; contains the nucleus and other parts of the cell needed to sustain its life.
Dendrites
Rootlike parts of a cell used to make synaptic connections with other neurons.
Resting potential
The normal state of a neuron; ions have a small negative charge; when cells become excited, it triggers an action potential which reverses the charge and causes the electrical signal to race along the axon.
Action potential
Occurs when information travels along the axon in the form of an electrical charge; it is the firing of the signal of the neuron.
Absolute threshold
If the excitatory signals, minus the inhibitory signals exceed a minimum intensity, the action potential is realized or crossed.
Refractory period
Each action potential is followed by a brief recharging period.
All-or-none principle
Once the action potential is released, there is no going back. The axon either fires or does not.
Depolarization
The initial movement of the action potential where the action passes from the resting potential in the cell body into the action potential in the axon.
Acetylcholine
Responsible for motor movement; lack of acetylcholine is associated with Alzheimer’s.
Dopamine
Responsible for motor movement and alertness; lack of dopamine is associated with Parkinson’s, an over abundance of dopamine is associated with schizophrenia.
Endorphins
Responsible for pain control; involved in addictions.
Serotonin
Responsible for mood control; lack of serotonin is associated with clinical depression.
GABA
Important inhibitory neurotransmitter; lack or excess can lead to seizures and sleep problems.
Glutamate
Excitatory neurotransmitter involved in memory; can cause migraines and seizures.
Norepinephrine
Responsible for alertness and arousal; can cause depression.
Afferent neurons
Sensory neurons that take information from the senses to the brain.
Efferent neurons
Motor neurons that take information from the brain to the rest of the body.
Interneurons
Once information reaches the brain or spinal cord, Interneurons take the messages and send them elsewhere in the brain or on to efferent neurons.
Central Nervous System
Consists of brain and spinal cord- all nerves encased in bone. The spinal cord transmit information from the rest of the body to the brain.