AP Psychology · Unit 2
Biological Bases of Behavior: every key term you need (+ practice quiz)
24 flashcard terms for AP Psychology Unit 2, written to match the course framework. Study them here, then drill them as interactive flashcards, or test yourself with the 10-question quiz — free, no account needed.
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Neuron The basic cell of the nervous system that receives, processes, and transmits electrochemical signals.
Dendrites Branchlike extensions that receive incoming messages and conduct impulses toward the cell body.
Axon The extension that carries neural impulses away from the cell body toward other neurons or muscles.
Myelin Sheath A fatty layer insulating the axon that speeds neural transmission; its breakdown causes multiple sclerosis.
Action Potential A brief electrical charge that travels down the axon when a neuron fires; operates all-or-none.
Resting Potential The negative charge (about -70 mV) inside a neuron when it is not firing, ready to be triggered.
All-or-None Principle A neuron either fires at full strength or not at all; stimulus intensity affects rate, not size, of firing.
Synapse The tiny gap between neurons across which neurotransmitters diffuse to relay messages.
Neurotransmitters Chemical messengers released into the synapse that bind to receptors on the next neuron.
Reuptake The reabsorption of excess neurotransmitters by the sending neuron; blocked by many antidepressants.
Dopamine Neurotransmitter influencing movement, reward, and attention; excess linked to schizophrenia, lack to Parkinson's.
Serotonin Neurotransmitter affecting mood, sleep, and appetite; low levels are linked to depression.
Acetylcholine Neurotransmitter enabling muscle action and memory; its loss is associated with Alzheimer's disease.
Central Nervous System The brain and spinal cord; processes information and directs the body's responses.
Peripheral Nervous System All nerves outside the CNS; includes the somatic and autonomic divisions.
Autonomic Nervous System Controls involuntary functions; its sympathetic branch arouses ('fight or flight') and parasympathetic calms.
Medulla Brainstem structure that controls vital reflexes such as heartbeat and breathing.
Cerebellum 'Little brain' at the rear that coordinates voluntary movement, balance, and some learning.
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Amygdala Limbic structure central to fear, aggression, and emotional responses.
Hippocampus Limbic structure essential for forming new explicit (conscious) memories.
Hypothalamus Regulates hunger, thirst, body temperature, and links the nervous system to the endocrine system.
Cerebral Cortex & Lobes Wrinkled outer layer of higher thought; four lobes: frontal, parietal, temporal, occipital.
Endocrine System Network of glands that secrete hormones into the bloodstream; the pituitary is the 'master gland.'
Neuroplasticity The brain's ability to reorganize and form new connections, especially after damage or learning.
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