AP Psychology Unit 3a: The Biological School Key Terms

Biological psychology

a branch of psychology concerned with the links between biology and behavior

Neuron

a nerve cell; the basic building block of the nervous system

Sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

Motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

Dendrite

the bushy, branching extensions of the neuron that receive messages and conduct impulses towards the cell body

Axon

the extension of a neuron, ending in branch terminal fibers, through which messages pass to other neurons or to muscles or glands

Myelin sheath

a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops 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 (tiny gap at this junction is synaptic gap)

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Reuptake

a neurotransmitter’s absorption

Endorphins

“morphine within”- natural, opiatlike 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

the brain and spinal cord

Peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body

Nerves

bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs

Somatic nervous system

the divisions of the peripheral nervous systems that controls the body’s skeletal muscles

Autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs

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

Reflex

a simple, automatic response to a sensory stimulus

Endocrine system

the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream

Hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissue

Adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress

Pituitary gland

the endocrine system’s most influential gland that regulates growth and controls other endocrine glands