2025 Unit 1 Quiz (Nervous System, Endocrine System, Psychoactive Drugs, Brain Scans)

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction; deficits linked with Alzheimer's disease

Dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system; deficits linked with Parkinson's & excess linked with schizophrenia

Endorphins

natural, opiate-like neurotransmitters linked to pain control and to pleasure; associated with exercise

GABA

An inhibitory neurotransmitter in the brain; calms the body

Glutamate

A major excitatory neurotransmitter; involved in memory & learning

Norepinephrine/Epinephrine

A neurotransmitter and hormone that corresponds to the fight-or-flight response; alerts and arouses the body for emergencies

Substance P

A neurotransmitter that is involved in the transmission of pain messages to the brain.

Autonomic Nervous System

the part of the peripheral nervous system that controls involuntary functions (digestion, breathing, etc.); connected to the glands and the muscles of the internal organs (such as the heart).

Central Nervous System

consists of the brain and spinal cord

Glial cells

cells in the nervous system that support, nourish, and protect neurons

Parasympathetic

the division of the autonomic nervous system that calms the body, conserving its energy; "rest-and-digest"

Peripheral Nervous System (PNS)

the sensory and motor neurons outside the brain and spinal cord that connect the central nervous system (CNS) to the rest of the body

Somatic Nervous System

the division of the peripheral nervous system that controls voluntary movement; nerves connected to the body's skeletal muscles

Sympathetic Nervous System

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations; fight-or-flight response

Action potential

a neural impulse; a brief electrical charge that travels down an axon as it is firing

Axon

A threadlike extension of a neuron that carries nerve impulses away from the cell body to the axon terminals

Axon Terminals

Branches at the end of the axon; where the electrical signal becomes chemical through the release of neurotransmitters across the synapse

Dendrites

Branchlike parts of a neuron that are specialized to receive information

Myelin sheath

A layer of fatty tissue segmentally encasing the fibers of neurons for insulation and protection; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

Refractory period

a brief period of inactivity after a neuron has fired

Resting potential

the state of the neuron when not firing a neural impulse

Reuptake

a neurotransmitter's reabsorption by the sending neuron

Soma

cell body of a neuron

Synapse

Gap between neurons

Threshold

the minimum level of stimulation required to trigger a neural impulse

Alcohol

Depressant; reduces inhibitions and induces relaxation

Amphetamines

Stimulant; accelerates body functions, associated with energy and mood changes, can cause days-long insomnia as users "tweak"

Barbiturates

Depressant; drugs that reduce anxiety and produce sleepiness.

Caffeine

Stimulant; found in coffee, tea, cola drinks, chocolate, and many over-the-counter medications to increase energy

Cocaine

a powerful and addictive stimulant, derived from the coca plant, producing temporarily increased alertness and euphoria; associated with aggression and depressive crashes

Ecstasy

a synthetic stimulant and mild hallucinogen; produces euphoria and social intimacy

Heroin

Depressant; Opiate/Narcotic drug derived from opium that is extremely addictive and dangerous

LSD

a powerful hallucinogenic drug; also known as acid (lysergic acid diethylamide)

Marijuana

a mild hallucinogen that causes relaxation and increased appetite

Nicotine

Stimulant; highly addictive psychoactive drug in tobacco

CT

computed tomography; x-ray of the brain

EEG

electroencephalogram; measures brain wave activity

fMRI

combination of PET & MRI; technique used to pinpoint the area of the brain that is active during particular tasks

MRI

a technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue; creates detailed 3D structure of the brain

PET

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

Agonist

mimics neurotransmitter activity

Antagonist

prevents or blocks neurotransmitter activity

All-or-None Law

principle that the action potential in a neuron does not vary in strength; the neuron either fires at full strength or it does not fire at all

oxytocin

A bonding hormone; released by the posterior pituitary that stimulates uterine contractions during childbirth and milk ejection during breastfeeding.

melatonin

A hormone manufactured by the pineal gland that produces sleepiness

ghrelin

A hunger-arousing hormone secreted by an empty stomach

leptin

A hormone produced by adipose (fat) cells that acts as a satiety factor in regulating appetite

adrenaline

A hormone released into the bloodstream in response to physical or mental stress

identical twins (monozygotic twins)

twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms

fraternal twins (dizygotic twins)

twins who develop from separate fertilized eggs; they are genetically no closer than brothers and sisters, but they share a fetal environment.