Psychology: Genetics, Evolution, and the Nervous System

Genetics and Evolution

Nature: The biological and genetic traits you inherit from your parents.
Evolutionary Perspective: A psychological approach that explains human behavior based on survival and reproduction needs.
Natural Selection: The process where organisms with traits best suited to their environment survive and pass on those traits.
Behavior Genetics: The study of how variation in genes affects human behavior.
Mutations: Random errors in gene replication that lead to changes in an organism's DNA.
Environment: Every non-genetic influence around us, from the food we eat to the people we meet.
Heredity: The genetic transfer of characteristics from parents to their biological children.
Genes: The biochemical units of heredity that make up our chromosomes.
Genome: The complete set of genetic instructions needed to make an entire organism.
Nurture: The environmental factors and life experiences that shape who we are.
Eugenics: A controversial historical movement aimed at improving the genetic quality of a human population through selective breeding.
Identical (Monozygotic) Twins: Twins who develop from a single fertilized egg that splits in two, making them genetically identical.
Fraternal (Dizygotic) Twins: Twins who develop from two separate fertilized eggs, making them no more genetically similar than ordinary siblings.
Interaction: The interplay that occurs when the effect of one factor (like environment) depends on another factor (like heredity).
Epigenetics: The study of how environmental factors can turn genes on or off without altering the underlying DNA sequence.

The Nervous System

Nervous System: The body's speedy, electrochemical communication network consisting of all nerve cells.
Central Nervous System: The core communication hub of the body consisting exclusively of the brain and spinal cord.
Nerves: Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.
Peripheral Nervous System: The sensory and motor neurons that connect the central nervous system to the rest of the body.
Somatic Nervous System: The division of the peripheral nervous system that controls the body's skeletal muscles for voluntary movement.
Autonomic Nervous System: The part of the peripheral nervous system that controls involuntary, automatic bodily functions like heart rate and digestion.
Sympathetic Nervous System: The division of the autonomic nervous system that arouses the body to mobilize energy during stressful situations.
Parasympathetic Nervous System: The division of the autonomic nervous system that calms the body to conserve energy after a stressful event.

Neurons and Their Components

Neurons: The basic building blocks of the nervous system that receive, process, and transmit information.
Cell Body: The part of a neuron that contains the nucleus and keeps the cell alive and functioning.
Dendrites: The bushy, branching extensions of a neuron that receive incoming messages from other cells.
Axon: The long extension of a neuron that passes electrical messages away from the cell body to other neurons.
Myelin: A fatty tissue layer that insulates axons and speeds up the transmission of neural impulses.
Synapse: The tiny junction gap where information is chemically transmitted from one neuron to another.
Glial Cells: Cells in the nervous system that support, nourish, and protect neurons.

Neuro-Communication and Reflexes

Reflex: A simple, automatic, and involuntary response to a sensory stimulus.
Reflex Arc: The neural pathway that controls a reflex action by bypassing the brain for a faster response.
Sensory Neurons: Neurons that carry incoming information from body tissues and sensory receptors to the central nervous system.
Motor Neurons: Neurons that carry outgoing information from the central nervous system to muscles and glands.
Interneurons: Neurons within the brain and spinal cord that communicate internally and process information between sensory inputs and motor outputs.