Unit 2 / Chpt. 2 - Biological Basis of Behavior Flashcards
Natural Selection
The process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.
Mutation
A sudden variation in an inheritable characteristic as distinguished from a variation that results from generations of gradual selection.
Evolutionary Psychology
Evolutionary psychology studies the ways adaptation and natural selection are connected with mental processes and behavior.
Behavioral Genetics
The area of biology and psychology that focuses on the transmission of traits that give rise to behavior.
Genotype
One’s genetic makeup based on the sequencing of the nucleotides we term A, C, G, and T.
Phenotype
One’s actual development and appearance based on one’s genotype and environmental influences.
Nature
The inborn, innate character of an organism.
Nurture
The sum total of the environmental factors that affect an organism from conception onward. (In another usage, nurture refers to the act of nourishing and otherwise promoting the development of youngsters.)
Epigenesis
The fact that children’s development reflects continuing bidirectional exchanges between their genetic heritage and the environments in which they find themselves or place themselves.
Neuron
A specialized cell of the nervous system that transmits messages.
Glia
Cells that nourish neurons, remove waste products from the nervous system, and help synchronize the messages sent by neurons.
Dendrites
Rootlike structures, attached to the cell body of a neuron, that receive impulses from other neurons.
Axon
A long, thin part of a neuron that transmits impulses to other neurons, an organ, or muscle from branching structures called terminal buttons.
Afferent Neurons
Neurons that transmit messages from sensory receptors to the spinal cord and brain. Also called sensory neurons.
Efferent Neurons
Neurons that transmit messages from the brain or spinal cord to muscles and glands. Also called motor neurons.
Myelin Sheath
The purpose of the myelin sheath is to allow impulses to transmit quickly and efficiently along the nerve cells. If myelin is damaged, the impulses slow down. This can cause diseases such as multiple sclerosis.
Nerve
A bundle of axons from many neurons.
Neural Impulse
The electro-chemical discharge of a nerve cell, or neuron. are messages that travel within neurons at somewhere between 2 miles an hour (in nonmyelinated neurons) and 225 miles an hour (in myelinated neurons). This speed is not impressive when compared with that of an electrical current in a toaster oven or a lamp, which can travel at close to the speed of light—more than 186,000 miles per second. Distances in the body are short, however, and a message will travel from a toe to the brain in perhaps 1/50th of a second.
Resting Potential
The electrical potential across the neural membrane when it is not responding to other neurons.
Action Potential
The electrical impulse that provides the basis for the conduction of a neural impulse along an axon of a neuron.
All-or-None Principle
The fact that a neuron fires an impulse of the same strength whenever its action potential is triggered.
Synapse
A junction between the axon terminals of one neuron and the dendrites or cell body of another neuron.
Neurotransmitters
Chemical substances involved in the transmission of neural impulses from one neuron to another.
Receptor Site
A location on a dendrite of a receiving neuron tailored to receive a neurotransmitter.
Synaptic Vesicles
Sacs called synaptic vesicles in the axon terminals contain neurotransmitters.
CNS
Brain and spinal cord.
Reflex
1an action that is performed as a response to a stimulus and without conscious thought.
Medulla
An oblong area of the hindbrain involved in regulation of heartbeat and respiration.