The Building Blocks of Neurons
These bushy, branching extensions of a neuron receive and integrate incoming messages, conducting electrical impulses toward the cell body.
What are dendrites?
This major neurotransmitter enables muscle action, learning, and memory; a decline in its producing neurons is linked to Alzheimer's disease.
What is acetylcholine (ACh)?
Composed of the brain and the spinal cord, this primary division serves as the body's central decision maker.
What is the central nervous system (CNS)?
Located at the front of the brain, these lobes enable high-level functions like planning, judgment, muscle movement, and personality control.
What are the frontal lobes?
Located at the base of the brainstem, this structure controls vital, automatic survival functions like heartbeat and breathing.
What is the medulla?
This primary category of psychoactive drugs—which includes alcohol, barbiturates, and opioids—calms neural activity and slows body functions
What are depressants?
This fatty tissue layer segmentally encases the axons of some neurons, enabling vastly greater transmission speed as neural impulses hop along the nodes.
What is the myelin sheath?
Naturally produced in response to pain and vigorous exercise, these natural, opioid-like neurotransmitters are linked to pain control and pleasure.
What are endorphins?
This subdivision of the peripheral nervous system enables voluntary control over our skeletal muscles.
What is the somatic nervous system?
This thick band of neural axon fibers connects the left and right cerebral hemispheres and allows messages to pass between them.
What is the corpus callosum?
Attached to the rear of the brainstem, this "little brain" processes sensory input, coordinates movement output and balance, and enables nonverbal learning.
What is the cerebellum?
This process occurs with regular use of a drug, requiring the user to take larger and larger doses to experience the same effect.
What is tolerance?
Known as the "worker bees" of the nervous system, these cells support, nourish, and protect neurons, while also playing a role in learning, thinking, and memory.
What are glial cells (or glia)?
An oversupply of this neurotransmitter is linked to schizophrenia, while an undersupply is linked to tremors and decreased mobility in Parkinson's disease.
What is dopamine?
When faced with a stressful situation, this division of the autonomic nervous system arouses the body and mobilizes its energy for "fight or flight".
What is the sympathetic nervous system?
This region at the rear of the frontal lobes controls voluntary bodily movements.
What is the motor cortex?
Sitting atop the brainstem, this pair of egg-shaped structures acts as the brain's sensory control center for all senses except smell.
What is the thalamus?
Derived from the coca plant, this powerful stimulant produces a rush of euphoria by blocking the reuptake of dopamine, serotonin, and norepinephrine.
What is cocaine?
This temporary resting pause occurs after a neuron fires, during which subsequent action potentials cannot occur until the axon returns to its resting state.
What is the refractory period?
This type of molecule decreases or blocks a neurotransmitter's action by occupying receptor sites without stimulating them.
What is an antagonist?
These specialized neurons process information within the brain and spinal cord, communicating internally between sensory inputs and motor outputs.
What are interneurons?
hese broad regions of the cerebral cortex are not involved in primary motor or sensory functions, but rather in higher mental tasks like learning, remembering, and thinking
What are association areas?
These two lima-bean-sized neural clusters in the limbic system are strongly linked to fear, rage, and emotional processing.
What is the amygdala?
Chemically known as MDMA, this club drug acts as both a stimulant and mild hallucinogen by releasing stored serotonin and blocking its reuptake.
What is Ecstasy (or Molly)?
This process involves the reabsorption of excess neurotransmitter molecules by the sending neuron after they have crossed the synaptic gap.
What is reuptake?
Known as the principal inhibitory neurotransmitter of the brain, an undersupply of this chemical is linked to seizures, tremors, and insomnia.
What is GABA (gamma-aminobutyric acid)?
This simple, automatic response to a sensory stimulus—such as the knee-jerk reaction—is governed by a pathway that bypasses the conscious brain.
What is a reflex (or reflex arc)?
Famous railroad worker whose 1848 tamping iron accident destroyed parts of his frontal lobes, dramatically altering his personality and emotional restraint.
Who is Phineas Gage?
Located below the thalamus, this key limbic structure regulates hunger, thirst, body temperature, and controls the endocrine system via the pituitary gland.
What is the hypothalamus?
The major active ingredient in marijuana that triggers a mix of effects, acts on cannabinoid receptors, and lingers in body fat tissues for a week or more.
What is THC (delta-9-tetrahydrocannabinol)?