Psychology Chapter 2 Key Terms
Biological Perspective – concerned with the links between bio and behavior. Includes psychologists working in
neuroscience, behavior genetics, and evolutionary psych. These researchers may call themselves behavioral
neuroscientists, behavior geneticists, psychological psychologists, or bio psychologists.
Neuron – a nerve cell; the basic building block of the nervous system.
Dendrites – a neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell
Axon – the neuron extension that passes messages through its branches to other neurons or to muscle or glands.
Myelin sheath – a fatty tissue layer segmentally encasing the axons of some neurons enables vastly greater
transmission speed as neural transmission speed as neural impulses hop from one node to the next.
Action Potential – a neural impulse; a brief electrical charge that travels down an axon.
Threshold – the level of stimulation required to trigger a neural impulse.
Synapse – the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving
neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.
Neurotransmitters – a chemical messengers that cross the synaptic gaps between neurons. When released by
the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving
neuron, thereby influencing whether that neuron will generate a neural impulse.
Reuptake – a neurotransmitter’s reabsorption by the sending neuron.
Endorphins – “morphine within” – natural, opiate like neurotransmitters linked to pain control and to pleasure.
Nervous System – The body’s speedy, electrochemical communication network, consisting of all the nerve
cells of the peripheral and central nervous systems.
Central Nervous System (CNS) the brain and spinal cord.
Peripheral Nervous System – the sensory and motor neurons that connect the central nervous system (cns) to
the rest of the body.
Nerves – bundled axons that form neural “cables” connecting the central nervous system with muscles, glands,
and sense organs.
Sensory Neurons – Neurons that carry incoming information from the sensory receptors to the brain and spinal
Motor Neurons – neurons that carry outgoing information from the brain and spinal cord to the muscles and
Interneurons – neurons within the brain and spinal cord that communicate internally and intervene between the
sensory inputs and motor outputs. Somatic Nervous System – the division of the peripheral nervous system that controls the body’s skeletal
muscles. Also called the skeletal nervous system
Autonomic Nervous System (ans) – the part of the peripheral nervous system that controls the glands and the
muscles of the internal organs (such as the heart). Its sympathetic division arouses its parasympathetic division
Sympathetic Nervous System – The division of the autonomic nervous system that arouses the body,
mobilizing its energy in stressful situations.
Parasympathetic Nervous System – the division of the autonomic nervous system that calms the body,
conserving its energy.
Adrenal Glands – a pair of endocrine glands that sit just above the kidneys and sec