Ch.05 CNS Flashcards
afferent division
The portion of the peripheral nervous system that carries information from the periphery to the central nervous system
afferent neuron
Neuron that possesses a sensory receptor at its peripheral ending and carries information to the central nervous system
ascending tract
A bundle of nerve fibers of similar function that travels up the spinal cord to transmit signals derived from afferent input to the brain
astrocyte
A type of glial cell in the brain; major functions include holding the neurons together in proper spatial relationship and inducing the brain capillaries to form tight junctions important in the blood-brain barrier
autonomic nervous system
The portion of the efferent division of the peripheral nervous system that innervates smooth and cardiac muscle and exocrine glands; composed of two subdivisions, the sympathetic nervous system and the parasympathetic nervous system
basal nuclei
Several masses of gray matter located deep within the white matter of the cerebrum of the brain; play an important inhibitory role in motor control
blood-brain barrier
Special structural and functional features of the brain capillaries that limit access of materials from the blood into the brain tissue
brain
The most anterior, most highly developed portion of the central nervous system
brain stem
The portion of the brain that is continuous with the spinal cord, serves as an integrating link between the spinal cord and higher brain levels, and controls many life-sustaining processes, such as breathing, circulation, and digestion
center
A functional collection of cell bodies within the central nervous system
central nervous system (CNS)
The brain and spinal cord
central sulcus (SUL-kus)
A deep infolding of the brain surface that runs roughly down the middle of the lateral surface of each cerebral hemisphere and separates the parietal and frontal lobes
cerebellum (ser+-uh-BEL-um)
The portion of the brain attached at the rear of the brain stem and concerned with maintaining proper position of the body in space and subconscious coordination of motor activity
cerebral cortex
The outer shell of gray matter in the cerebrum; site of initiation of all voluntary motor output and final perceptual processing of all sensory input as well as integration of most higher neural activity
cerebral hemispheres
The cerebrumUs two halves, which are connected by a thick band of neuronal axons
cerebrospinal fluid
A special cushioning fluid that is produced by, surrounds, and flows through the central nervous system
cerebrum
The division of the brain that consists of the basal nuclei and cerebral cortex
cranial nerves
The 12 pairs of peripheral nerves, the majority of which arise from the brain stem
diencephalon
The division of the brain that consists of the thalamus and hypothalamus
dorsal root ganglion
A cluster of afferent neuronal cell bodies located adjacent to the spinal cord
effector organs
The muscles or glands that are innervated by the nervous system and that carry out the nervous systemUs orders to bring about a desired effect, such as a particular movement or secretion
efferent division (EF-er-ent)
The portion of the peripheral nervous system that carries instructions from the central nervous system to effector organs
electroencephalogram (EEG) (i-lek+-trox -in-SEF-uh-luh-gram+)
Neuron that carries information from the central nervous system to an effector organ
free radicals
Very unstable electron-deficient particles that are highly reactive and destructive
frontal lobes
The lobes of the cerebral cortex that lie at the top of the brain in front of the central sulcus and that are responsible for voluntary motor output, speaking ability, and elaboration of thought
ganglion
A collection of neuronal cell bodies located outside the central nervous system
ganglion cells
The nerve cells in the outermost layer of the retina and whose axons form the optic nerve
glial cells
Serve as the connective tissue of the CNS and help support the neurons both physically and metabolically; include astrocytes, oligodendrocytes, ependymal cells, and microglia
gray matter
The portion of the central nervous system composed primarily of densely packaged neuronal cell bodies and dendrites
hippocampus (hip-oh-CAM-pus)
The elongated, medial portion of the temporal lobe that is a part of the limbic system and is especially crucial for forming long-term memories
hypothalamus
The brain region located beneath the thalamus that is concerned with regulating many aspects of the internal fluid environment, such as water and salt balance and food intake; serves as an important link between the autonomic nervous system and endocrine system
integrating center
A region that determines efferent output based on processing of afferent input
interneuron
Neuron that lies entirely within the central nervous system and is important for integrating peripheral responses to peripheral information as well as for the abstract phenomena associated with the RmindS
limbic system
A functionally interconnected ring of forebrain structures that surrounds the brain stem and is concerned with emotions, basic survival and sociosexual behavioral patterns, motivation, and learning
myelin
An insulative lipid covering that surrounds myelinated nerve fibers at regular intervals along the axonUs length; each patch of myelin is formed by a separate myelin forming cell that wraps itself jelly-roll fashion around the neuronal axon
nerve
A bundle of peripheral neuronal axons, some afferent and some efferent, enclosed by a connective tissue covering and following the same pathway
neuroendocrinology
The study of the interaction between the nervous and endocrine systems
neuroglia
same as glial cells
occipital lobes
The lobes of the cerebral cortex that are located posteriorly and are responsible for initially processing visual input
oligodendrocytes
The myelin-forming cells of the central nervous system
parasympathetic nervous system
The subdivision of the autonomic nervous system that dominates in quiet, relaxed situations and promotes body maintenance activities such as digestion and emptying of the urinary bladder
parietal lobes
The lobes of the cerebral cortex that lie at the top of the brain behind the central sulcus and contain the somatosensory cortex
peripheral nervous system (PNS)
Nerve fibers that carry information between the central nervous system and other parts of the body
plasticity
The ability of portions of the brain to assume new responsibilities in response to the demands placed on it
primary motor cortex
The portion of the cerebral cortex that lies anterior to the central sulcus and is responsible for voluntary motor output
proprioception
Awareness of position of body parts in relation to each other and to surroundings
receptor
See sensory receptor or receptor site
reflex
Any response that occurs automatically without conscious effort; the components of a reflex arc include a receptor, afferent pathway, integrating center, efferent pathway, and effector
releasing hormone
A hypothalamic hormone that stimulates the secretion of a particular anterior pituitary hormone
reticular activating system
Ascending fibers that originate in the reticular formation and carry signals upward to arouse and activate the cerebral cortex
reticular formation
A network of interconnected neurons that runs throughout the brain stem and initially receives and integrates all synaptic input to the brain
sensory afferent
Pathway coming into the central nervous system that carries information that reaches the level of consciousness
sensory receptor
An afferent neuronUs peripheral ending, which is specialized to respond to a particular stimulus in its environment
somatic nervous system
The portion of the efferent division of the peripheral nervous system that innervates skeletal muscles; consists of the axonal fibers of the alpha motor neurons
somatic sensation
Sensory information arising from the body surface, including somesthetic sensation and proprioception
somatosensory cortex
The region of the parietal lobe immediately behind the central sulcus; the site of initial processing of somesthetic and proprioceptive input
somesthetic sensations
Awareness of sensory input such as touch, pressure, temperature, and pain from the bodyUs surface
spinal reflex
A reflex that is integrated by the spinal cord
stimulus
A detectable physical or chemical change in the environment of a sensory receptor
subcortical regions
The brain regions that lie under the cerebral cortex, including the basal nuclei, thalamus, and hypothalamus
sympathetic nervous system
The subdivision of the autonomic nervous system that dominates in emergency (Rfight- or-flightS) or stressful situations and prepares the body for strenuous physical activity
target cell receptors
Receptors located on a target cell that are specific for a particular chemical mediator
target cells
The cells that a particular extracellular chemical messenger, such as a hormone or a neurotransmitter, influences
temporal lobes
The lobes of the cerebral cortex that are located laterally and that are responsible for initially processing auditory input
thalamus
The brain region that serves as a synaptic integrating center for preliminary processing of all sensory input on its way to the cerebral cortex
tract
A bundle of nerve fibers (axons of long interneurons) with a similar function within the spinal cord
vagus nerve
The tenth cranial nerve, which serves as the major parasympathetic nerve
ventricle
A lower chamber of the heart that pumps blood into the arteries
white matter
The portion of the central nervous system composed of myelinated nerve fibers
