The Brain Flashcards
central nervous system
The portion of the nervous system consisting of the brain and spinal cord.
spinal cord
A collection of neurons and supportive tissue running from the base of the brain down the center of the back, protected by a column of bones (spinal column).
peripheral nervous system
All portions of the nervous system outside the brain and spinal cord; it includes sensory and motor nerves.
somatic nervous system
The subdivision of the peripheral nervous system that connects to the sensory receptors and to skeletal muscles; sometimes called the skeletal nervous system.
autonomic nervous system
The subdivision of the peripheral nervous system that regulates the internal organs and glands.
sympathetic nervous system
The subdivision of the autonomic nervous system that mobilizes bodily resources and increases the output of energy during emotion and stress.
parasympathetic nervous system
The subdivision of the autonomic nervous system that operates during relaxed states and that conserves energy.
glia
Cells that support, nurture, and insulate neurons, remove debris when neurons die, enhance the formation and maintenance of neural connections, and modify neuronal functioning.
dendrites
A neuron’s branches that receive information from other neurons and transmit it toward the cell body.
cell body
The part of the neuron that keeps it alive and determines whether it will fire.
axon
A neuron’s extending fiber that conducts impulses away from the cell body and transmits them to other neurons.
myelin sheath
A fatty insulation that may surround the axon of a neuron.
nerve
A bundle of nerve fibers (axons and sometimes dendrites) in the peripheral nervous system.
neurogenesis
The production of new neurons from immature stem cells.
stem cells
Immature cells that renew themselves and have the potential to develop into mature cells; given encouraging environments, stem cells from early embryos can develop into any cell type.
synapse
The site where transmission of a nerve impulse from one nerve cell to another occurs; it includes the axon terminal, the synaptic cleft, and the receptor sites in the membrane of the receiving cell.
action potential
A brief change in electrical voltage that occurs between the inside and the outside of an axon when a neuron is stimulated; it serves to produce an electrical impulse.
neurotransmitter
A chemical substance that is released by a transmitting neuron at the synapse and that alters the activity or a receiving neuron.
endorphins
Chemical substances in the nervous system that are similar in structure and action to opiates; they are involved in pain reduction, pleasure, and memory, and are known technically as endogenous opioid peptides.
hormones
Chemical substances, secreted by organs called glands, that affect the functioning of other organs.
endocrine glands
Internal organs that produce hormones and release them into the bloodstream.
melatonin
A hormone, secreted by the pineal gland, that is involved in the regulation of daily biological rhythms.
adrenal hormones
Hormones that are produced by the adrenal glands and that are involved in emotion and stress.
sex hormones
Hormones that regulate the development and functioning of reproductive organs and that stimulate the development of male and female sexual characteristics; they include androgens, estrogens, and progesterone.
localization of function
Specialization of particular brain areas for particular functions.
brain stem
The part of the brain at the top of the spinal cord, consisting of the medulla and the pons.
pons
A structure in the brainstem involved in, among other things, sleeping, waking, and dreaming.
medulla
A structure in the brain stem responsible for certain automatic functions, such as breathing and heart rate.
reticular activating system (RAS)
A dense network of neurons found in the core of the brain stem; it arouses the cortex and screens incoming information.
cerebellum
A brain structure that regulates movement and balance, and that is involved in the learning of certain kinds of simple responses.
thalamus
A brain structure that relays sensory messages to the cerebral cortex.
hypothalamus
A brain structure involved in emotions and drives vital to survival; such as fear, hunger, thirst, and reproduction; it regulates the autonomic nervous system.
pituitary gland
A small endocrine gland at the base of the brain, which releases many hormones and regulates other endocrine glands.
limbic system
A group of brain areas involved in emotional retains and motivated behavior.
amygdala
A brain structure involved in the arousal and regulation of emotion and the initial emotional response to sensory information.
hippocampus
A brain structure involved in the storage of new information in memory.
cerebrum
The largest brain structure , consisting of the upper part of the brain; divided into two hemispheres, it is in charges of most sensory motor, and cognitive processes.
cerebral hemispheres
The two halves of the cerebrum.
corpus callosum
The bundle of nerve fibers connecting the two cerebral hemispheres.
lateralization
Specialization of the two cerebral hemispheres from particular operations.
cerebral cortex
A collection of several thin layers of cells covering the cerebrum; it is largely responsible for higher mental functions.
occipital lobes
Lobes at the lower back part of the brain’s cerebral cortex; they contain areas that receive visual information.
parietal lobes
Lobes at the top of the brain’s cerebral cortex; they contain areas that receive information on pressure, pain, touch, and temperature.
temporal lobes
Lobes at the sides of the brain’s cerebral cortex; they contain areas involved in hearing, memory, perception, emotion, and (in the left lobe, typically) language comprehension
frontal lobes
Lobes at the front of the brain’s cerebral cortex; they contain areas involved in short-term memory, higher-order thinking, initiative, social judgement, and (in the left lobe typically) speech production.
visual cortex
Where visual signals are processed. Located in the occipital lobe.
somatosensory cortex
Receives information about pressure, pain, touch, and temperature from all over the body. Located in the parietal lobe.
auditory cortex
Processes sounds. Located in the temporal lobe.
Wernicke’s area
It is involved in language comprehension. Located in the left temporal lobe.
motor cortex
Issues orders to the 600 muscles of the body that produce voluntary movement. Located in the frontal lobe.
Broca’s area
Handles speech production. Located in the frontal lobe.
