Heredity and Neurological Changes – Vocabulary Flashcards

Key terms from the notes on heredity and CNS development, with concise definitions.

Heredity

Total set of characteristics biologically transmitted from parent to offspring.

Genotype

Total genetic inheritance of an individual.

Phenotype

Physical-visible characteristics resulting from genotype and environment.

CNS (Central Nervous System)

Central nervous system; brain and spinal cord—the primary processing center.

PNS (Peripheral Nervous System)

All nerve fibers outside the CNS; connects CNS to body.

Spinal cord

Transmits signals between brain and body; coordinates reflexes.

Brain stem

Lower brain region connecting to the spinal cord; supports basic life functions.

Cerebral cortex

Outer layer of the cerebrum involved in higher-order processing.

Basal ganglia

Deep brain structures involved in movement regulation.

Cerebellum

Brain region coordinating balance, posture, and refined movements.

Afferent

Nerve fibers carrying information into the CNS.

Efferent

Nerve fibers carrying motor commands away from the CNS.

Neuron

Basic nerve cell; structure includes soma, dendrites, axon; forms synapses.

Dendrites

Branchlike extensions that receive signals from other neurons.

Axon

Long fiber that transmits impulses away from the neuron cell body.

Synapse

Junction where neurons communicate via neurotransmitters.

Myelin

Lipid sheath around axons that speeds electrical conduction.

Motor unit

A neuron and all the muscle fibers it innervates.

Ascending tracts

Sensory pathways that carry information toward the brain.

Descending tracts

Motor pathways that carry commands from brain to muscles.

Action potential

Electrical impulse that travels along a neuron to transmit signals.

Brain plasticity

Brain’s ability to change and adapt in response to experience.

Critical periods

Windows of opportunity during development when experiences strongly shape brain organization.

Brain size

Adult brain weighs about 3.5 pounds and uses roughly 15% of blood and 25% of oxygen.

Neurogenesis

Formation of new neurons after birth; influenced by activities like running and music.

Musicians’ brain

Some brain areas for movement/coordination are larger in adult musicians; playing enhances these areas.

Second language critical periods

A development window in which acquiring a new language is most effective due to plasticity.

Brain lateralization

Hemispheres appear symmetrical but have specialized functions; corpus callosum connects them.

Aging changes in the brain

Aging is associated with slowing and decreased specialization and function.

Gene-environment interaction

Heredity interacts with environment; nature and nurture jointly shape development.

Six biologic events in CNS development

Proliferation, integration/differentiation, myelination, cell death, early developmental changes, and the overall sequence of CNS development.