What are the functional units of the nervous system? Flashcards Preview

Physiological Psychology > What are the functional units of the nervous system? > Flashcards

Flashcards in What are the functional units of the nervous system? Deck (41):
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glial cell

Nervous-system cell that provides insulation, nutrients, and support and that aids in repairing neurons and eliminating waste products.

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mutation

Alteration of an allele that yields a different version of the allele.

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cell body (soma)

Core region of the cell containing the nucleus and other organelles for making proteins.

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Huntington's disease

Hereditary disease characterized by chorea (ceaseless, involuntary, jerky movements) and progressive dementia, ending in death.

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pyramidal cell

Distinctive interneuron found in the cerebral cortex.

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transgenic animal

Product of technology in which number of genes or a single gene from one species is introduced into the genome of another species and passed along and expressed in subsequent generations.

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homozygous

Having two identical alleles for a trait.

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multiple sclerosis (MS)

Nervous-system disorder that results from the loss of myelin (glial-cell covering) around neurons.

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allele

Alternate form of a gene; a gene pair contains two alleles.

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Schwann cell

Glial cell in the peripheral nervous system that myelinates sensory and motor axons.

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bipolar neuron

Sensory neuron with one axon and one dendrite.

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terminal button (end foot)

Knob at the tip of an axon that conveys information to other neurons.

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astrocyte

Star-shaped glial cell that provides structural support to neurons in the central nervous system and transports substances between neurons and blood vessels.

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pump

Protein in the cell membrane that actively transports a substance across the membrane.

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wild type

Refers to a normal (most common in a population).

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gate

Protein embedded in a cell membrane that allows substances to pass through the membrane on some occasions but not on others.

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blood-brain barrier

Tight junctions between the cells that compose blood vessels in the brain, providing a barrier to the entry of an array of substances, including toxins, into the brain.

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axon hillock

Juncture of soma and axon where the action potential begins.

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channel

Opening in a protein embedded in the cell membrane that allows the passage of ions.

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synapse

Junction between one neuron and another that forms the information-transfer site between neurons.

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protein

Folded-up polypeptide chain.

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sensory neuron

Neuron that carries incoming information from sensory receptors into the spinal cord and brain.

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axon

'Root,' or single fiber, of a neuron that carries messages to other neurons.

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hydrocephalus

Buildup of pressure in the brain and, in infants, swelling of the head caused if the flow of cerebrospinal fluid is blocked; can result in retardation.

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heterozygous

Having two different alleles for the same trait.

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interneuron

Association neuron interposed between a sensory neuron and a motor neuron; thus, in mammals, interneurons constitute most of the neurons of the brain.

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tumor

Mass of new tissue that grows uncontrolled and independent of surrounding structures.

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Purkinje cell

Distinctive interneuron found in the cerebellum.

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Tay-Sachs disease

Inherited birth defect caused by the loss of genes that encode the enzyme necessary for breaking down certain fatty substances; appears 4 to 6 months after birth and results in retardation, physical changes, and death by about age 5.

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dendrite

Branching extension of a neuron's cell membrane that greatly increases the surface area of the cell and collects information from other cells.

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ependymal cell

Glial cell that makes and secretes cerebrospinal fluid; found on the walls of the ventricles in the brain.

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myelin

Glial coating that surrounds axons in the central and peripheral nervous systems; prevents adjacent neurons from short-circuiting.

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somatosensory neuron

Brain cell that brings sensory information from the body into the spinal cord.

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microglia

Glial cells that originate in the blood, aid in cell repair, and scavenge debris in the nervous system.

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oligodendroglia

Glial cells in the central nervous system that myelinate axons.

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Down syndrome

Chromosomal abnormality resulting in mental retardation and other abnormalities, usually caused by an extra chromosome 21.

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dendritic spine

Protrusion from a dendrite that greatly increases the dendrite's surface area and is the usual point of dendritic contact with the axons of other cells.

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axon collateral

Branch of an axon

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paralysis

Loss of sensation and movement due to nervous-system injury.

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motor neuron

Neuron that carries information from the brain and spinal cord to make muscles contract.

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gene

DNA segment that encodes the synthesis of a particular protein.