Term
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Definition
| sort of like a telephone line very fast and can communicate |
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Term
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Definition
| a little bit slower. In our eyes it acts fast but in comparison with the nervous system it is slower |
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Term
| MAJOR FUNCTIONS OF THE NERVOUS SYSTEM: |
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Definition
1.Sensory input,receiving stimuli
2.Integration
3.Control of muscles and glands
4.Homeostasis
5.Mental activity: learning and accessing |
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Term
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Definition
| What responds to the stimuli, some time of muscle tissue or glandular tissue. |
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Term
| CENTRAL NERVOUS SYSTEM (CNS) |
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Definition
located along the midline of the body.
Made up of brain and spinal cord
integration, processing and coordinating sensory data and motor commands. Majority of this takes place in the CNS |
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Term
| PERIPHERAL NERVOUS SYSTEM (PNS) |
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Definition
-All nervous tissue outside of the CNS is the PNS
-outside CNS
-delivery system to and from CNS
-info is either directed to the CNS or going away from CNS
-PNS is then divided into two sections depending on which direction information is flowing
-bundles of axons (nerve fibers) carry information and motor commands
-nerves are bundles of nerve fibers with the blood vessels and connective tissues
-cranial nerves are connected to brain
-spinal nerves are connected to spine |
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Term
| TWO MAJOR ANATOMICAL DIVISIONS OF THE NERVOUS SYSTEM: |
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Definition
1. Central Nervous system
2. Peripheral Nervous system |
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Term
| THE PERIPHERAL NERVOUS SYSTEM IS DIVIDED INTO TWO SECTIONS: |
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Definition
1. Sensory (afferent)
2. Motor (efferent) |
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Term
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Definition
•brings sensory information to CNS from receptors in tissues and organs
-receptors detect changes in environment
•receptors may be neurons or other specialized cells
This section is divided also depending on direction
-Information in |
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Term
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Definition
•Carries motor commands from CNS to muscles and glands (effectors)
-Associated with some type of movement
-Information out |
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Term
| COMPONENTS OF THE MOTOR PNS: |
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Definition
1. Somatic nervous system
2. Autonomic nervous system |
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Term
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Definition
| •controls skeletal muscles, voluntary or involuntary |
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Term
| AUTOMATIC NERVOUS SYSTEM: |
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Definition
•controls smooth muscle, cardiac muscle and glandular activity
•two divisions: sympathetic and parasympathetic |
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Term
| CELLS OF THE NERVOUS SYSTEM: |
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Definition
1.Neurons
2.Neuroglia/ glial |
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Term
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Definition
-functional units, cells that conduct electrical impulses.
-Contain:Soma, Dendrites, axon, synapse |
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Term
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Definition
| Specialized to conduct electrical impulses |
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Term
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Definition
•cell body
•contains nucleus and most of the organelles
•lack centrioles |
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Term
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Definition
•sensitive processes that extend from soma
•sensitive processes
•branched
-Receive information from the environment |
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Term
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Definition
•long cytoplasmic process
•propogates action potential: carries it down the length of the axon
•axolemma (cell membrane) may or may not be covered by sections of glial cells: referred to as myelination |
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Term
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Definition
Communication junction between a neuron and another cell
•presynaptic cell sends message/ the talking cell
•postsynaptic cell receives message/ listening cell
•communication is via release of neurotransmitters (example: ACh)
communication occurs by the release of chemical messengers referred to as neurotransmitters
•neuromuscular junction or neuroglandular junction |
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Term
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Definition
| insulation of an axon. Speeds up action potential propegation or speeds up communication. |
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Definition
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Term
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Definition
specialized area of axon where communication with other cells takes place
•trigger zone |
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Term
| AT THE SYNAPTIC TERMINAL: |
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Definition
-The presynaptic cell releases neurotransmitters
-The neurotransmitters move across the synaptic cleft (space between cell membranes)
-Neurotransmitters bind receptors on the postsynaptic cell's membrane
-The postsynaptic cell alters its activity |
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Term
| NEURON STRUCTURAL CLASSIFICATION: |
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Definition
Based on dendrite relationship with the soma and axon
1. Bipolar neuron: dendrites extend in one direction; axon in the other direction
2. Unipolar neuron: processes are continuous; soma lies to the side, has an axon and no dendrites
3. Multipolar neuron: several dendrites and one axon |
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Term
| NEURON FUNCTIONAL CLASSIFICATION |
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Definition
Classified on the type of signal that is being conveyed.
1. Sensory neurons:
afferent division of the PNS; receptor to CNS; unipolar
Part of the afferent division of the PNS
Carry information from receptors to the CNS
Usually unipolar
Somatic sensory neurons: detect changes in the external environment
Visceral sensory neurongs: detect changes in the internal environment
2. Motor neurons: efferent division of the PNS
Part of the efferent division of the PNS
Carries commands from the CNS to the effectors
Modifies activity of the peripheral tissues and organs
Somatic motor neurons innervate skeletal muscle
Visceral motor neurons innervate all other tissue types
3. Interneurons: association neurons; only in CNS
Between neurons
They are located between sensory neuron and motor neuron
Connection between the sensory and motor neurons
Distribute information
Coordinate motor activities |
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Term
| NEUROGLIAL CELLS (GLIAL CELLS) |
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Definition
-Supporting cells of the nervous system
-Do not conduct nerve impulses
Neurons would not function without these cells |
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Term
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Definition
1. ependymal cells: epithelial cells found in central canal of the spinal cord and the ventricles of the brain; secrete cerebrospinal fluid (CSF)
line the open pockets of the CNS. The open areas of the CNS include the spinal canal in the brain we have ventricles, both are lined by these cells
Secrete the cerebrospinal fluid
2. astrocytes: maintain a barrier between the interstitial fluid of the CNS and the circulation (blood); structural framework of CNS; stabilize injured tissue; adjust composition of the CSF
form a blood brain barrier to maintain homeostasis
Provide a structural framework for CNS
Stabilize injured tissue
Adjust the composition of the cerebrospinal fluid
3. oligodendrocytes: extensions of these cells wrap around the axons of neurons (myelination)
cells that myelinate the axons of the CNS neuron
4. microglia: clean up and surveillance
These clean up debris so they are phagocytic cells
Surveillance looking for pathogens that have invaded
Going around and looking for bad things and getting rid of them engulf it |
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Term
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Definition
1. Satellite cells: amphicytes; insulate soma, located around the soma and they do the same thing as astrocytes. They maintain composition of extracellular fluid
2. Schwann cells: insulate axons: myelinate axons in the PNS |
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