Human Physiology Chapter 5: The Central Nervous System BIOL 2305-017 (23314)
Terms in this set (166)
One the of two major regulatory systems in the body. Consists of the central nervous and peripheral nervous systems.
Central Nervous System (CNS)
Consists of the brain and spinal cord.
Lazy eye. In some cases, the unused eye goes blind due to lack of use.
Peripheral Nervous System (PNS)
Consists of nerve fibers that carry information from the CNS to other parts of the body. Divided into afferent and efferent system.
Carries information toward the CNS.
Carries information away from the CNS.
The organs that carry out the desired effect.
Somatic Nervous System
Consists of the motor neurons that supply the skeletal system.
Autonomic Nervous System
Consists of the motor neurons that innervates the smooth and cardiac tissues as well as the glands. Divided into the sympathetic and parasympathetic nervous systems.
Sympathetic Nervous System
Prepares body for fight or flight.
Parasympathetic Nervous System
Prepares body for rest and digest.
Bring signals toward the CNS. These begin in the PNS and end in the CNS.
These are in the peripheral system but begin in the CNS. Take signals to the effector organs.
These are located entirely in the CNS. Take signals from afferent neurons and take them either to the brain then the efferent neurons or directly to the efferent neurons.
"Neuroglia" Nonexcitable supporting cells that surround and wrap neurons. 4 types: Astrocytes, microglial cells, oligodendrocytes, and ependymal cells.
"Star Cells" 7 functions: (1) Hold the neurons together in proper spatial relationships. (2) Guide neurons to final destinations during fetal brain development. (3) Cause anatomical and functional changes that are responsible for establishing the blood-brain barrier. (4) Important in brain repair and in neural scar formation. (5) Take up and degrade glutamate and gamma-aminobutyric acid. Essentially, regulation of chemical messengers. (6) Take up K+ from the brain ECF when action potential activity outpaces the Na+-K+ pump. (7) Enhancement of synapse formation and modification of synaptic transmission via chemical signaling with neurons.
Form myelin sheaths around neurons.
Defend the CNS by phagocytizing invading microorganisms and injured and broken-down neurons. Release nerve growth factor (which helps neurons and other neuroglia) during resting stage.
Line the internal cavities of the brain and spinal cord. Form a permeable membrane that fills the cavity and tissues with cerebrospinal fluid. Serve as neural stem cells to form neurons and neuroglial cells.
These are the interconnected channels in the brain that are continuous with the central canal.
The central tunnel in the middle of the spinal cord.
Three layers of connective tissues. From most superficial to deepest: (1) Dura mater, (2) arachnoid mater, and (3) pia mater.
Tough, inelastic covering consisting of two parts, the periosteal and meningeal layers. Has sinuses that are filled with blood.
A delicate, vascularized layer. The second layer in the meninges.
This is the space between the arachnoid and pia maters. Filled with CSF.
Penetrate through gaps in the overlying dura and project into the dural sinuses. CSF is reabsorbed across these surfaces and into the blood in the sinuses.
The deepest meninges. Maintains contact with the brain and spinal cord. Highly vascular.
Cerebrospinal Fluid (CSF)
A watery broth that comes into cushions the brain. Does not directly bathe the neurons.
These are found in the roofs of the 4 ventricles. Highly vascularized masses that descend from the pia mater. Form the CSF.
"Water on the brain" CSF accumulates and damages brain.
Blood-brain barrier (BBB)
Prevents toxins from crossing over into the brain. Allows only carefully regulated materials through.
An oxygen-binding cell that brings oxygen to the brain.
The act of knowing. Refers to the ability to be self-aware and make judgments.
The largest portion of the brain. Divided into left and right hemispheres. Each hemisphere is connected by the corpus callosum.
A band of 300 million neurons which connects the two halves of the brain.
The thin superficial layer of gray matter which covers the inner white core.
In the CNS, this consists of neuron cell bodies, their dendrites, and most neuroglial cells.
In the CNS, consists of myelinated axons. Appearance due to lipid composition of myelin.
Responsible for initial processing of sensory input to th cortex.
These cells send fibers down the spinal cord from the cortex to terminate on efferent motor neurons that innervate skeletal muscles.
Located on posterior side of the brain. Process initial visual input.
Located on the lateral sides of the brain. Interpret sound.
This fissure separates frontal and parietal lobes of brain.
Located posterior to central sulcus. Responsible for receiving and interpreting sensory information.
Located anterior to the central sulcus. Responsible for voluntary motor control, speaking, and elaboration of thought.
Sensations that come from the surface of the body.
Located in the anterior portion of each parietal lobe immediately posterior to the central sulcus. Responsible for cortical processing and perception of somesthetic input as well as proprioceptive input.
The awareness of body position.
Receives sensor information about each body part from the opposite side (E.g. The right one of this receives information about the left side of the body).
Primary Motor Cortex
Located in posterior portion of frontal lobe just anterior to the central sulcus. Confers volunary control over movement from skeletal muscles.
Sends motor information to the muscles on the opposite hemisphere. Motor efferent information does not originate here.
The widespread pattern of neuronal discharge prepares the motor homunculus.
A planned sequence of neuronal discharges that will bring about a desired effect.
Supplementary motor area
Lies on the medial side of each hemisphere and anterior tot he primary motor cortex. Helps prepare programming for complex sequences of movements.
Located on the lateral surface of each hemisphere in front of the primary motor cortex. Important in orienting the body and arms toward a specific target. Guided by posterior parietal cortex's information.
Posterior parietal cortex
Gives information to the premotor cortex which helps guide it. Lies posterior to the primary somatosensory cortex.
Parts of the brain grow larger with increased use. A use-it-or-lose-it rule.
An ability to change or be functionally changed in response to the demands placed upon it.
A complex form of communication that uses words to convey ideas.
Controls speaking ability. Located on left hemisphere and closely associated with areas that control articulation.
Located on the left hemisphere at the juncture of the parietal, temporal, and occipital lobes. Deals with understanding language. Also responsible for composing coherent patterns of speech. Receives information from occipital lobe (reading), the auditory cortex (hearing), and the somatosensory cortex (Braille).
Most of these result from strokes. Damage to Wernicke's area results in an inability to attach proper meaning to words and cannot attach proper meaning to words.
A defect in the mechanical aspect of speech.
Difficulty reading due to incorrect interpretation of words.
Involved in higher functions. Three of these: (1) Prefrontal association cortex, (2) parietal-temporal-occipital association cortex, and (3) the limbic association cortex.
Prefrontal association cortex
Just anterior to the premotor cortex. Its role include planning voluntary activity, decision making, creativity, and personality traits.
Parietal-temporal-occipital association cortex
Located at the junction of the temporal, occipital, and parietal lobes. Pools and integrates somatic, auditory, and visual sensation for complex perceptual processing. Gives the complete picture of a situation.
Limbic association cortex
Located on inferior and and adjoining medial portion of the each temporal lobe. Deals with memory, motivation, and emotion.
Left Cerebral Hemisphere
Excels in logical, analytic, sequential, and verbal tasks. Processes information in a fine-detail, fragmentary way.
Right Cerebral Hemisphere
Excels in nonlanguage skills. Processes information in a Big-picture, holistic way.
A graphic recording that is produced from electrodes placed on the scalp.
Occur when a large collection of neurons abnormally undergo synchronized action potentials.
Include the basal nuclei, the thalamus, and the hypothalamus. Interact with cortex.
"Basal Ganglia" Consist of several masses of gray matter deep in the white matter.
A functioning group of neutron cell bodies. Functions include: (1) Inhibiting muscle tone, (2) selecting and maintaining purposeful motor activity while suppressing useless movements, and (3) helping monitor and coordinate slow, sustained contractions.
Associated with a deficiency of dopamine. Results in rigid muscles, useless movements, and slow initiation and carrying out of motor functions.
A midline structure that forms the walls of the third ventricular cavity.
The synaptic integrating system for preliminary processing of all sensory input on its way to the cortex.
A collection of of specific nuclei and associated fibers that lie inferior to the thalamus. Functions include control of body T, thirst and urine output, food intake, anterior pituitary gland hormone secretion, posterior pituitary hormones, uterine contractions and milk ejection, serves as major autonomic nervous system control, control of emotion and behavior, and participates in the sleep-wake cycle.
Not a separate structure. A ring of forebrain structures that surround the brain stem and are interconnected by intricate neuron pathways.
Encompasses subjective feelings and moods plus the physical responses associate with these feelings.
On the interior underside of the temporal lobe. Processes inputs that give rise to the sensation of fear.
Basic Behavioral Patterns
These are controlled by the limbic system. Deal with survival of the individual and the species.
"Reward" and "Punishment" Centers
These centers attribute certain actions with certain feelings (e.g. Association of pain with touching a hot pan or association of pleasure with eating an apple).
The ability to direct behavior toward certain goals.
Represent the subjective urges associated with specific bodily needs that motivates appropriate behavior to satisfy those needs.
These affect the moods of individuals.
The acquisition of knowledge or skills as a consequence of experience, instruction, or both.
The storage of acquired knowledge for later recall.
The neural change responsible for retention or storage of knowledge.
The retention of information for a short period of time.
The retention of information for a long period of time.
The process of transferring and fixing short-term memory traces into long-term memory traces.
Consolidates immediate information with long-term memory to work out a current scenario.
Some suggest that when long-term memory is recalled, it is put into inactive state when finished.
Two forms. One form results in a loss of information from the past. The other is an inability to retain new information.
The elongated, medial portion of the temporal lobe that is part of the limbic system. Plays an important role in short-term memory involving the integration of of various related stimuli and is also crucial from consolidation into long-term memory.
Memories of specific places, people, times, etc.
Involve motor skills gained through repetitive training.
A decreased responsiveness to repetitive presentations of an indifferent stimulus.
An increased responsiveness to mild stimuli following a strong or noxious stimulation.
Long-Term Potentiation (LTP)
Refers to prolonged increase in the strength of existing synaptic connections.
A nonselective cation channel. This channel's binding with glutamate allows calcium and sodium to enter the postsynaptic cell.
Primarily responsible for for generating EPSPs in response to glutamate activation.
Thought to be the retrograde messenger. Performs many roles in the body.
A positive regulatory protein that activates the genes that are important in long-term memory storage.
A repressor of CREB associated protein-synthesis.
Immediate early genes (IEGs)
Govern the synthesis of proteins that encode long-term memory.
A highly folded baseball-sized part of the brain that is inferior to the occipital lobe of the cortex and is attached to the back of the superior part of the brain stem.
Important for maintaining balance and eye control.
Enhances muscle tone and coordinates skilled, voluntary movements.
Plays a role in planning and initiating voluntary activity by providing input to the cortical motor areas. Also stores procedural memories.
Consists of the medulla, pons, and midbrain. All information must pass through this area of the brain. 5 major functions: (1) Cranial nerves originate from here. (2) Contains neuronal clusters that regulate heart and blood vessel function, respiration, and many digestive activities. (3) Regulation of muscle reflexes involved in equilibrium and posture. (4) Contains the reticular formation and reticular activating system. (5) Centers that govern sleep are traditionally thought to be here.
These nerves innervate the head and neck. There is one exception to these nerves.
This is the tenth cranial nerve. This nerve innervates the thoracic and abdominal cavities.
This network of interconnected neurons runs throughout the entire brain stem and into the thalamus. Receives and integrates all incoming sensory synaptic input.
Reticular Activating System (RAS)
These are ascending fibers originating in the reticular formation carry signals upward to arouse and activate the cerebral cortex.
Refers to subjective awareness of the external world and self, including awareness of one's own thoughts.
A normal cyclic variation in awareness of surroundings. Caused by various stages in sleep. Caused by three different neural systems: (1) Arousal system, (2) slow-wave system, and (3) paradoxical sleep center.
An active process, not just the absence of wakefulness.
Occurs in four stages, each displaying progressively slower EEG waves of higher amplitude.
A 10-15 minute episode that punctuates the end of each slow-wave sleep cycle. During this period, EEG pattern abruptly becomes similar to that of an awake person.
Part of the reticular activating systemm originating in the brain stem.
Slow-wave system center
Located in the hypothalamus. Contains sleep-on neurons that induce sleep.
Paradoxical sleep center
Houses REM sleep-on neurons, which become very active during REM sleep.
Those who suffer from this disease fall asleep with no warning.
A long, slender cylinder of nerve tissue that extends from the brain stem. 2 main functions: (1) Connect the brain the brain to the rest of the body and (2) integrates reflex activity between afferent and efferent input.
Emerge from spaces in the vertebrae. 8 pairs of cervical, 12 pairs of thoracic, 5 pairs of lumbar, 5 pairs of sacral, and 1 pair coccygeal nerve.
The thick bundle of elongated nerve roots within the lower vertebral canal.
Bring afferent information.
Take efferent information.
Ventral Spinocerebellar tract
An ascending pathway that originates in the spinal cord and runs up the ventral margin of the cord with several synapses along the way until it eventually terminates in the cerebellum.
Ventral Corticospinal Tract
Originates in the motor region of the cerebral cortex, then travels down the ventral portion of the spinal cord, and terminates in the spinal cord on the cell bodies of efferent motor neurons supplying skeletal muscles.
"Posterior horn" This is the posterior part of the gray matter of the spinal cord. Contains cell bodies of interneurons on which afferent neurons terminate.
"Anterior horn" Contains cell bodies of the efferent motor neurons supplying skeletal muscles.
Autonomic nerve fibers supplying cardiac and smooth muscle and exocrine galnds originate at cell bodies found here.
Afferent fibers carrying incoming signals from peripheral receptors enter the spinal cord through the dorsal root.
Dorsal Root Ganglion
The cell bodies for the afferent neurons at each level are clustered together here.
Dorsal and ventral roots combine to form this. Contains both afferent and efferent fibers traversing between a particular region of the body and the spinal cord.
Efferent fibers carrying signals to muscles and glands exit through here.
A bundle of peripheral neurons covered by a connective tissue that is also traveling the same pathway.
This is a specific nerve that innervates a certain region of the body's surface.
One part of the body may be injured resulting in another part feeling pain.
Any response that occurs without conscious effort. Two kinds, simple and conditioned.
"Basic reflexes" These are unlearned reflexes that require no training.
"Conditioned reflexes" A result of practice and learning.
The neural pathway involved in accomplishing reflex activity. Usually consists of 5 components: (1) Receptor, (2) afferent pathway, (3) integrating center, (4) efferent pathway, and (5) Effector.
This part of the reflex arc responds to a stimulus.
A detectable physical or chemical change int he environment of the receptor.
Carries afferent information.
Afferent information is carried here for processing.
Carries efferent information to the effector.
A muscle or gland that carries out a desired result.
A reflex integrated by the spinal cord.
When the body reflexively retracts a limb
A neural connection that involves simultaneous inhibition and simulation.
The body reflexively extends a limb.
Involves only one synapse between the afferent and efferent neurons.
Involves more than one synapse. Involves an interneuron.
Crossed extensor reflex
One limb extends while the other contracts.