How does the nervous system function? Flashcards
gray matter
Areas of the nervous system composed predominantly of cell bodies and capillary blood vessels that function either to collect and modify information or to support this activity.
Parkinson’s disease
Disorder of the motor system correlated with a loss of dopamine in the brain and characterized by tremors, muscular rigidity, and a reduction in voluntary movement.
nucleus (pl. nuclei)
A group of cells forming a cluster that can be identified with special stains to form a functional grouping.
neocortex (cerebral cortex)
Newest, outer layer (“new bark”) of the forebrain, composed of about six layers of gray matter; creates our reality.
tegmentum
Floor (area below the ventricle) of the midbrain; a collection of nuclei with movement-related, species-specific, and pain-perception functions.
tract
Large collection of axons coursing together within the central nervous system.
cerebral cortex
Thin, heavily folded film of nerve tissue composed of neurons that is the outer layer of the forebrain. Also called neocortex.
stroke
Sudden appearance of neurological symptoms as a result of severely interrupted blood flow.
Tourette’s syndrome
Disorder of the basal ganglia characterized by tics, involuntary vocalizations (including curse words and animal sounds), and odd, involuntary movements of the body, especially of the face and head.
dermatome
Body segment corresponding to a segment of the spinal cord.
somatic nervous system (SNS)
Part of the PNS that includes the cranial and spinal nerves to and from the muscles, joints, and skin that produce movement, transmit incoming sensory input, and inform the CNS about the position and movement of body parts.
frontal lobe
Part of the cerebral cortex often generally characterized as performing the brain’s “executive” functions, such as decision making; lies anterior to the central sulcus and beneath the frontal bone of the skull.
meninges
Three layers of protective tissue - dura mater, arachnoid, and pia mater - that encase the brain and spinal cord.
vertebrae (sing. vertebra)
The bones that form the spinal column.
parasympathetic division
Part of the autonomic nervous system; acts in opposition to the sympathetic division - for example, preparing the body to rest and digest by reversing the alarm response or stimulating digestion.
corpus callosum
Band of white matter containing about 200 million nerve fibers that connects the two cerebral hemispheres to provide a route for direct communication between them.
afferent
Conducting toward a central nervous system structure.
cerebrospinal fluid (CSF)
Clear solution of sodium chloride and other salts that fills the ventricles inside the brain and circulates around the brain and spinal cord beneath the arachnoid layer in the subarachnoid space.
limbic system
Disparate forebrain structures lying between the neocortex and the brainstem that form a functional system controlling affective and motivated behaviors and certain forms of memory; includes cingulate cortex, amygdala, and hippocampus, among other structures.
orienting movement
Movement related to sensory inputs, such as turning the head to see the source of a sound.
cytoarchitectonic map
Map of the neocortex based on the organization, structure, and distribution of the cells.
autonomic nervous system (ANS)
Part of the PNS that regulates the functioning of internal organs and glands.
diencephalon
The “between brain” that integrates sensory and motor information on its way to the cerebral cortex.
hypothalamus
Diencephalon structure that contains many nuclei associated with temperature regulation, eating, drinking, and sexual behavior.
nerve
Large collection of axons coursing together outside the central nervous system.
white matter
Areas of the nervous system rich in fat-sheathed neural axons that form the connections between brain cells.
gyrus (pl. gyri)
A small protrusion or bump formed by the folding of the cerebral cortex.
sulcus (pl. sulci)
A groove in brain matter, usually a groove found in the neocortex or cerebellum.
efferent
Conducting away from a central nervous system structure.
midbrain
Central part of the brain that contains neural circuits for hearing and seeing as well as orienting movements.
hindbrain
Evolutionarily the oldest part of the brain; contains the pons, medulla, reticular formation, and cerebellum, structures that coordinate and control most voluntary and involuntary movements.
Alzheimer’s disease
Degenerative brain disorder related to aging that first appears as progressive memory loss and later develops into generalized dementia.
cranial nerve
One of a set of 12 nerve pairs that control sensory and motor functions of the head, neck, and internal organs.
law of Bell and Magendie
The general principle that sensory fibers are located dorsally and motor fibers are located ventrally.
neuroplasticity
The nervous system’s potential for physical or chemical change that enhances its adaptability to environmental change and its ability to compensate for injury.
excitation
Increase in the activity of a neuron or brain area.
reticular formation
Midbrain area in which nuclei and fiber pathways are mixed, producing a netlike appearance; associated with sleep-wake behavior and behavioral arousal.
temporal lobe
Part of the cerebral cortex that functions in connection with hearing, language, and musical abilities; lies below the lateral fissure, beneath the temporal bone at the side of the skull.
inhibition
Decrease in the activity of a neuron or brain area.
parietal lobe
Part of the cerebral cortex that functions to direct movements toward a goal or to perform a task, such as grasping an object; lies posterior to the central sulcus and beneath the parietal bone at the top of the skull.
phenotypic plasticity
An individual’s capacity to develop into more than one phenotype.
sympathetic division
Part of the autonomic nervous system; arouses the body for action, such as mediating the involuntary fight-or-flight response to alarm by increasing heart rate and blood pressure.
occipital lobe
Part of the cerebral cortex where visual processing begins; lies at the back of the brain and beneath the occipital bone.
basal ganglia
Subcortical forebrain nuclei that coordinate voluntary movements of the limbs and body; connected to the thalamus and to the midbrain.
tectum
Roof (area above the ventricle) of the midbrain; its functions are sensory processing, particularly visual and auditory, and the production of orienting movements.
forebrain
Evolutionarily the newest part of the brain; coordinates advanced cognitive functions such as thinking, planning, and language; contains the limbic system, basal ganglia, and the neocortex.
brainstem
Central structures of the brain, including the hindbrain, midbrain, thalamus, and hypothalamus, that are responsible for most unconscious behavior.
ventricle
One of four cavities in the brain that contain cerebrospinal fluid that cushions the brain and may play a role in maintaining brain metabolism.
thalamus
Diencephalon structure through which information from all sensory systems is integrated and projected into the appropriate region of the neocortex.
