Neuroscience
how the body and brain enable emotions, memories, and sensory experiences
biological psychology
a branch of psychology concerned with the links between biology and behavior
phrenology
An early approach to explaining the functions of the brain by trying to link the physical structure of the skull with a variety of characteristics.
neurons
a specialized cell transmitting nerve impulses; a nerve cell.
Cell body
the region of the neuron that includes structures that nourish the cell, and a necleus containing DNA
Dendrites
Branchlike parts of a neuron that are specialized to receive information.
Axon
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
Myelin sheath
A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.
Synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
glial cells
cells in the nervous system that support, nourish, and protect neurons
resting potential
electrical charge across the cell membrane of a resting neuron
action potential
the spike in voltage that passes through the axon of a neuron, the purpose of which is to convey information
All-or-none
referring to the fact that a neuron either fires completely or does not fire at all
Neurotransmitters
chemical messengers that cross the synaptic gaps between neurons
receptor sites
Locations on a receptor neuron into which a specific neurotransmitter fits like a key into a lock.
reuptake
process by which neurotransmitters are taken back into the synaptic vesicles
central nervous system
a major component of the human nervous system that includes the brain and spinal cord
peripheral nervous system
The part of the nervous system that is outside the central nervous system and comprises the cranial nerves excepting the optic nerve, the spinal nerves, and the autonomic nervous system.
spinal cord
Nerves that run up and down the length of the back and transmit most messages between the body and brain
Sensory neurons
neurons that carry incoming information from the sensory receptors to the brain and spinal cord
motor neurons
neurons that transmit information from the central nervous system 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
reflex arc
A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.
nerves
bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs
somatic nervous system
the division of the peripheral nervous system that controls the body's skeletal muscles
autonomic nervous system
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
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
hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
pituitary gland
The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.
thyroid gland
produces hormones that regulate metabolism, body heat, and bone growth
adrenal glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
Cerebrum
Area of the brain responsible for all voluntary activities of the body
corpus callosum
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
split-brain operation
a surgical procedure that involves cutting the corpus callosum
Lateralization
cognitive function that relies more on one side of the brain than the other
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
Neuroplasticity
the ability within the brain to constantly change both the structure and function of many cells in response to experience or trauma
neurogenesis
the formation of new neurons
stem cells
unspecialized cells that are able to renew themselves for long periods of time by cell division
cerebral cortex
The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.
frontal lobes
the portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments
parietal lobes
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position
occipital lobes
portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields
temporal lobes
portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear
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
limbic system
neural system located below the cerebral hemispheres; associated with emotions and drives
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
Hypothalamus
A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.
Amygdala
two lima bean-sized neural clusters in the limbic system; linked to emotion.
Hippocampus
A neural center located in the limbic system that helps process explicit memories for storage.
Forebrain
The largest and most complicated region of the brain, including the thalamus, hypothalamus, limbic system, and cerebrum.
Midbrain
A small part of the brain above the pons that integrates sensory information and relays it upward.
reticular formation
a nerve network in the brainstem that plays an important role in controlling arousal
hindbrain
Includes areas of the brain responsible for fundamental life-sustaining processes.
pons
A brain structure that relays information from the cerebellum to the rest of the brain
medulla
the base of the brainstem; controls heartbeat and breathing
Cerebellum
A large structure of the hindbrain that controls fine motor skills.