Neuroscience and Genetics: Brain Functions, Neuron Structure, and Genetic Variation

Frontal Cortex

Core psychological functions, including thinking and reflection.

Phineas Gage

Railroad worker whose frontal cortex was damaged after an accident. His endorphins reduced pain (by blocking substance P). His personality changed drastically; he survived physically but his mental state never recovered.

Corpus Callosum Severing

Stops seizures but prevents communication between left and right hemispheres (two "separate" brains).

Broca's Area

Producing language (speech).

Wernicke's Area

Understanding language.

Hippocampus

Learning and memory.

Amygdala

Negative emotion (fear, anger, etc.).

Hypothalamus

Regulates homeostasis (hunger, thirst, body temp, sexual behavior, hormones).

Neurons

Basic building blocks of the nervous system.

Soma

Cell body; contains nucleus.

Dendrites

Receive signals from other neurons.

Axon

Sends signals away from soma.

Terminal Buttons

Release neurotransmitters.

Myelin Sheath

Speeds signal transmission.

Nodes of Ranvier

Gaps in the myelin sheath.

Synaptic Cleft

Tiny gap between neurons where neurotransmitters cross.

Neurotransmitters

Chemical messengers between neurons.

Reuptake

Neurotransmitters are reabsorbed after sending a signal.

Genetic Variation

Differences in DNA between individuals; key for adaptation.

Chromosomes

Long DNA strands (helix-shaped).

Genes

DNA sequences that code for traits.

Alleles

Different versions of a gene.

Alleles per Gene

2 (one from each parent).

Genotype

Genetic makeup (instructions).

Phenotype

Observable traits (results).