PSYC 208 Chapter Notes -Evolutionary Psychology, Endocrine System, Sexual Maturity
Document Summary
Weight: 1300 1400 grams (adult); 350-400 grams (newborn) Number of total neurons: 100 billion: send/receive signals, process information (most important part of brain) Umber of cortical neurons: 20 billion: when studying human type brain/human-like psychology behavior, outside in cerebrum. Number of synapses in cortex: 150000000000000: synapse: interface between two neurons to communicate with each other. Percentage of genes expressed in the brain: 55: suggests that brain is primary target of natural selection in human evolution. Two types of neurons: gray matter: neurons without myelin sheath (processing information, white matter: neurons with myelin sheath (connect different regions) Myelin sheath insulates and it accelerates the speed by which info travels. Primarily used to transport information (super highways: two neurons don"t touch each other (synaptic cleft) Information travels only in one direction: soma: body of the cell (genes are housed there) Action potential: electrical charge indicating a neuron has fired : when it sends its message.
