Behavioral Genetics and Nervous System - Vocabulary Flashcards

A set of vocabulary flashcards covering behavioral genetics concepts and the basic structure and function of the nervous system.

Behavioral genetics

Study of how genetic and environmental factors interact to determine traits and behavior.

Nature vs. Nurture Debate

Question of the relative contributions of genetics (nature) and environment (nurture) to human traits.

Heritability

Genetic contribution to characteristics; the extent to which variation is due to genes.

Environment (in behavioral genetics)

Experiences, upbringing, and stimulation that influence development and traits.

Genetic predisposition

A tendency to develop certain traits or disorders influenced by genes, but not deterministically inevitable.

Monogenic transmission

Trait or disorder determined by a single gene; often rare.

Huntington's disease

An example of a monogenic disorder caused by a single gene; rare.

Polygenic transmission

Most traits are influenced by multiple genes that interact to produce characteristics.

Schizophrenia (polygenic)

A trait that can involve multiple genes; exemplifies polygenic transmission.

Twin studies

Research method to estimate heritability by comparing identical and fraternal twins, often raised together or apart.

Monozygotic twins (identical)

Twins from one zygote; same sex; extremely high genetic similarity.

Dizygotic twins (fraternal)

Twins from two zygotes; can have different physical characteristics; share about half their genes.

Jim Springer & Jim Lewis study

Famous case of identical twins separated at birth with striking similarities in traits and life events.

Epigenetics

Environment and biology constantly interact; environment can change gene expression without changing DNA sequence.

Gene activation/deactivation

Environmental factors can turn genes on or off, affecting expression.

Chromosome structure and epigenetics

Epigenetic changes do not alter the underlying chromosome structure.

Depression gene (example)

Illustrates how a gene may remain dormant until a major life stressor triggers activation.

Nervous system

Body's communication network that processes sensory input and coordinates responses.

Peripheral Nervous System (PNS)

All nerves outside the brain and spinal cord (to muscles, organs, skin).

Somatic Nervous System

PNS subdivision controlling voluntary, conscious movements.

Autonomic Nervous System

PNS subdivision controlling involuntary bodily functions; has sympathetic and parasympathetic divisions.

Sympathetic Nervous System

Arousing division responsible for the fight-or-flight response.

Parasympathetic Nervous System

Relaxing division that returns the body to a resting state and maintains homeostasis.

Central Nervous System (CNS)

Brain and spinal cord; the main processing center of the nervous system.

Spinal Cord Functions

Relays sensory input to motor output and controls reflexes that bypass the brain.

Reflex

Involuntary knee-jerk or automatic responses that do not require brain processing.

Neuron

Basic unit of the nervous system that processes and transmits information via electrical and chemical signals.

Sensory Neurons

Carry information from sense organs to the brain.

Interneurons

Link sensory and motor neurons; often numerous connections within the CNS.

Motor Neurons

Carry commands from the brain to muscles to generate movement.

Glial Cells

Support neurons with nutrients, cleanup toxins, and maintain neuron vitality.

Soma (cell body)

Contains nucleus and organelles; sustains cell health.

Dendrites

Receive neurotransmitters from other neurons; act as antennas for incoming signals.

Nucleus

Contains DNA and genetic material; provides instructions for neuron function.

Axon

Carries electrical impulses and neurotransmitters away from the cell body.

Myelin Sheath

Fatty insulation around the axon that speeds transmission and protects the axon.

Terminal Buttons/Axon Terminals

Release neurotransmitters into the synaptic cleft.

Action Potential

Electrical firing process; involves depolarization and repolarization; resting potential is -70 mV.

Resting Potential

Neuron at rest with a membrane potential of -70 millivolts and no neurotransmitter activity.

Depolarization

Sodium channels open; Na+ enters; membrane potential shifts from -70 mV toward +40 mV.

Repolarization

Phase that restores the neuron to its resting potential after depolarization.