Unit 1 Lecture Notes

Flashcards based on lecture notes about nature vs. nurture, the nervous system, the brain, neurotransmitters, and psychoactive drugs.

Nature vs. Nurture

The debate over the relative contributions of genetic inheritance and environmental factors to human development.

Epigenetics

Environmental factors that can affect gene expression.

Identical (Monozygotic) Twins

Twins that originate from the same zygote and share the same genes.

Fraternal (Dizygotic) Twins

Twins that originate from separate zygotes and do not share the same genes.

Heritability

The proportion of variation among individuals that we can attribute to genes.

Motor (Efferent) Neurons

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

Sensory (Afferent) Neurons

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

Interneurons

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

Dendrites

The branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

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.

Axon

The extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands.

Soma

The cell body of a neuron, which contains the nucleus.

Central Nervous System (CNS)

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.

Autonomic Nervous System

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 calms.

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.

Resting Potential

The state of a neuron when it is not firing a neural impulse.

Action Potential

A neural impulse; a brief electrical charge that travels down an axon.

Firing Threshold

The level of stimulation required to trigger a neural impulse.

Refractory Period

A period of inactivity after a neuron has fired.

Reuptake

A neurotransmitter's reabsorption by the sending neuron.

Thalamus

Brain structure that directs sensory and motor traffic.

Midbrain

Connects higher and lower parts of the brain

Medulla

Part of the brainstem that controls involuntary reflexes such as breathing and heart rate.

Cerebellum

The 'little brain' attached to the rear of the brainstem; its functions include processing sensory input and coordinating movement output and balance.

Hypothalamus

Brain structure that regulates hunger, thirst, body temperature, and sexual behavior.

Hippocampus

A neural center located in the limbic system; helps process explicit memories for storage.

Amygdala

Two lima bean-sized neural clusters in the limbic system; linked to emotion, especially anger and aggression.

Serotonin

Neurotransmitter involved in mood, low levels are associated with depression, high levels with autism.

Dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system. Low levels are associated with Parkinson's, high levels with Schizophrenia.

Acetylcholine (ACh)

A neurotransmitter that enables learning and memory and also triggers muscle contraction. Low levels are associated with Alzheimers

Norepinephrine/Epinephrine

A neurotransmitter involved in arousal, as well as in learning and mood regulation

Endorphins

Opiate-like neurotransmitters linked to pain control and to pleasure.

Glutamate

A major excitatory neurotransmitter; involved in memory.

GABA

A major inhibitory neurotransmitter; linked with stress reduction.

Psychoactive Drugs

A chemical substance that alters perceptions and moods.

Depressants

Drugs that reduce neural activity and slow body functions.

Stimulants

Drugs that excite neural activity and speed up body functions.

Hallucinogens

Psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input.

Agonists

Mimic neurotransmitters, binding to receptors and activating them.

Antagonists

Block neurotransmitters by binding to receptors and preventing activation