Barron's: Chapter 3 - Biological Bases of Behavior Flashcards
Neuroanatomy
- the study of the parts and function of neurons
Neuron
- individual nerve cells
Dendrites
- rootlike parts of the cell that stretch out from the cell body. dendrites grow to make synaptic connections with other neurons (see Synapse, below)
Cell body (also called the soma)
- contains the nucleus and other parts of the cell needed to sustain its life
Axon
- wirelike structure ending in the terminal buttons that extends from the cell body
Myelin sheath
- a fatty covering around the axon of some neurons that speeds neural impulses
Terminal buttons (also called end buttons, axon terminal, terminal branches of axon, and synaptic knobs)
- 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 on the dendrites of neurons like a key fits into a lock
Synapse
- the space between the terminal buttons of one neuron and the dendrites of the next neuron
Receptor sites
- proteins that are on the surface of each cell and act as little receivers
Threshold
- the level of strength a stimulus must reach to be detected
Action potential
- the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell.
All-or-none principle
- when a neuron either fires completely or its does not fire
Neural firing
- an electrochemical process. electricity travels within the cell (from the dendrites to the terminal buttons), and chemicals (neurotransmitters) travel between cells in the synapse. Electricity does not jump between the neurons
Excitatory neurotransmitters
- they excite the next cell into firing
Inhibitory neurotransmitters
- they inhibit the next cell from firing
Acetylcholine
- Function: Motor movement
- Problems Associated with an Excess of Deficit: lack of acetylcholine is associated with Alzheimer’s disease
Dopamine
- Function: Motor movement and alertness
- Problems Associated with an Excess of Deficit: Lack of dopamine is associated with Parkinson’s disease, an overabundance is associated with schizophrenia
Endorphins
- Function: Pain control
- Problems Associated with an Excess of Deficit: involved in addictions
Serotonin
- Function: mood control
- Problems Associated with an Excess of Deficit: lack of serotonin is associated with clinical depression
GABA
- Function: Important inhibitory neurotransmitter
- Problems Associated with an Excess of Deficit: seizures, sleep problems
Glutamate
- Function: excitatory neurotransmitter, involved in memory
- Problems Associated with an Excess of Deficit: migraines, seizures
Norepinephrine
- Function: alertness, arousal
- Problems Associated with an Excess of Deficit: depression
Afferent neurons (or sensory neurons)
- take information from the senses to the brain (you can think of afferent nerves as taking information in at the brain)
Efferent neurons (or motor neurons)
- take information from the brain to the rest of the body (you can think of efferent nerves as carrying information that exits the brain)
Central nervous system (CNS)
- consists of our brain and spinal cord - all the nerves housed within bone (the skull and vertebrae)
Spinal cord
- a bundle of nerves that run through the center of the spine, it transmits information from the rest of the body to the brain
Peripheral nervous system (PNS)
- consists of all the other nerves in your body - all the nerves not encased in bone
Somatic nervous system
- controls our voluntary muscle movement
Accidents
- Phineas Gage was in an accident that damaged the front part of his brain
- his behavior changed and he became highly emotional and impulsive
Lesions
- the removal or destruction of part of the brain
Electroencephalogram (EEG)
- detects brain waves
- widely used in sleep research to identify the different stages of sleep and dreaming