AP Psych Unit 1 Biology Part 1

neuron

a nerve cell; the basic building block of the nervous system

dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

axon

the neuron extension that passes messages through its branches to other neurons or to muscles or glands

myelin sheath

a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next

glial cells

cells in the nervous system that support, nourish, and protect neurons

action potential

the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell.

resting potential

the state of the neuron when not firing a neural impulse

threshold

the level of stimulation required to trigger a neural impulse

Synapse

the junction between the axon of the sending neuron and the dendrite or cell body of the receiving neuron

Reuptake

process by which neurotransmitters are taken back into the synaptic vesicles

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Endorphins

"morphine within"--natural, opiate-like neurotransmitters linked to pain control

Agonist

a molecule that increases a neurotransmitter's action

antagonist

inhibits a neurotransmitter's action

central nervous system

consists of the brain and spinal cord

peripheral nervous system

A division of the nervous system consisting of all nerves that are not part of the brain or spinal cord.

sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

somatic nervous system

A subdivision of the peripheral nervous system; enables voluntary actions to be undertaken due to its control of skeletal muscles

autonomic nervous system

A subdivision of the peripheral nervous system that controls involuntary activity of muscles, internal organs, and glands

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream

pituitary gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, it regulates growth and controls other endocrine glands.

EEG

An amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.

Medulla

found in the base of the brainstem; controls heartbeat and breathing

Pons

A brain structure that relays information from the cerebellum to the rest of the brain; regulates sleep/relaxation

Thalamus

the brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

reticular formation

a nerve network that travels through the brainstem and thalamus and plays an important role in controlling arousal

Cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

limbic system

neural system located below the cerebral hemispheres; associated with emotions and drives

Amygdala

A limbic system structure involved in memory and emotion, particularly fear and aggression.

Hypothalamus

a neural structure that directs eating, drinking, body temperature, and sexual behavior; helps govern the endocrine system via the pituitary gland, and is linked to emotion

Hippocampus

A neural center located in the limbic system that helps process explicit memories for storage; necessary for making new memories

Cerebrum

Largest part of the brain; responsible for voluntary muscular activity, vision, speech, taste, hearing, thought, and memory.

cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

frontal lobe

A region of the cerebral cortex associated with reasoning, planning, parts of speech, movement, emotions, and problem solving

parietal lobe

A region of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position

occipital lobe

A region of the cerebral cortex that processes visual information

temporal lobe

A region of the cerebral cortex responsible for hearing and language.

motor cortex

an area at the rear of the frontal lobes that controls voluntary movements

somatosensory cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations

association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking

Plasticity

the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience

neurogenesis

the formation of new neurons

Broca's area

Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.

Wernicke's area

controls language reception - a brain area involved in language comprehension and expression; usually in the left temporal lobe

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them

split brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers connecting them

Heritability

The proportion of variation among individuals that we can attribute to genes. It may vary, depending on the range of populations and environments studied.

Epigenetics

the study of environmental influences on gene expression that occur without a DNA change