Term
Origin -
Insertion -
Body - |
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Definition
- The site of muscle's attachment to the more stable bone.
- The site of a muscle's attachment to the more moveablebone.
- The fleshy part of a muscle located between the origin andinsertion of a muscle. |
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Definition
| - A mechanical advantage. The force created to achievemovement. |
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Definition
| A rigid structure that can move around a fixed point(called the fulcrum). |
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Term
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Definition
| The force which causes movement. (i.e. the muscle) |
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Definition
Resistance
- The force which opposes movement. |
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Term
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Definition
Prime Mover
- The muscle that contracts to produce the desiredmovement. |
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Term
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Definition
| The muscle that stretches and yields to the agonist. |
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Term
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Definition
| The muscle(s) that prevent unwanted movement and aid inthe movement of the agonist. |
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Definition
| The muscle(s) that stabilize the origin of the agonist. |
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Term
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Definition
| The muscle(s) that stabilize the origin of the agonist. |
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Term
| Central Nervous System (CNS) |
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Definition
1. Brain
2. Spinal Cord
B. Peripheral Nervous System
1. Somatic Nervous System
2. Autonomic Nervous System
a. Sympathetic Nervous System
b. Parasympathetic Nervous System
3. Enteric Nervous System |
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Term
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Definition
Soma = Perikaryon
- contains one centrally located nucleus
- contains Nissl Bodies, Rough Endoplasmic Reticulum |
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Term
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Definition
| - extensions from the cell body that receive signals(then transmits them towards the nucleus |
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Term
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Definition
| - extension from the cell body that transmits signalstowards the synapse |
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Term
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Definition
| - region where the axon joins the cell body |
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Term
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Definition
| - cytoplasm and cell membrane of the axon |
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Term
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Definition
| - branches that come off of the axon |
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Term
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Definition
- the end of the axon that contacts the synapse
- vesicles that contain neurotransmitter can befound in these structures |
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Term
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Definition
| - the site of communication between the axon and itsend organ |
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Term
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Definition
- the mechanism that transports axoplasm fromthe cell body towards the synapse
- material travels at a rate of 1 to 5 mm/day |
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Definition
- moves material along the axon in bothdirections, ex. synaptic vesicles
- material travels at a rate of 200 to 400mm/day |
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Term
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Definition
- a lipid/protein coating that surrounds the axonsof certain neurons
- the region between the myelin sheaths are calledthe Nodes of Ranvier
- these structures speed up nerve impulsetransmission |
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Term
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Definition
| a collection of unmyelinated neuron |
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Term
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Definition
| a collection of myelinated neurons |
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Term
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Definition
- has several dendrites and one (or more) axon
- found in the Brain and Spinal Cord |
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Term
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Definition
- has one axon and one dendrite
- associated with the eye and ear |
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Term
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Definition
- the dendrite and axon leave the cell body from one area
- associated with sensory neurons |
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Term
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Definition
Glia = Glial cells
- cells that support the function of the Nervous System |
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Term
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Definition
1. Astrocytes
2. Oligodendrocytes
3. Microglia
4. Ependymal cells
5. Schwann cell
6. Satellite cells |
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Term
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Definition
- located in the CNS
- provide nutritional support and the proper chemicalenvironment to Neurons |
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Term
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Definition
- in CNS
- produce myelin sheaths |
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Term
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Definition
- in CNS
- mobile macrophage |
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Term
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Definition
- in CNS
- line the ventricles of the Brain
- produce Cerebral Spinal Fluid (CSF) |
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Term
Schwann cell
- in PNS
- produce myelin sheaths |
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Definition
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Term
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Definition
| the outermost layer of the cell, contains thenucleus |
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Term
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Definition
- in PNS
- nutritional support to Neurons |
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Term
| Resting Membrane Potential (RMP) - |
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Definition
the electrical potential across the axon membrane, this is produced by the different ions located on each side of the membrane
- outside is positive, inside is negative |
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Term
| Extracellualr vs. intracellular |
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Definition
- extracellular area has more Sodium and Chloride ions
- intracellular area has more potassium ions, phosphates, andamino acids |
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Term
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Definition
| is approximately equal to -70 mV (i.e. more negativeintracellularly) |
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Term
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Definition
- located in the axolemma
- open and close in response to changes in voltage
- ex. Voltage Gated Na+ Channels
Voltage Gated K+ Channels |
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Term
| Sodium/Potassium ATPase Pumps |
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Definition
- located in axolemma
- takes care of ion (i.e. Na+ and K+) leakage across the axonmembrane |
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Term
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Definition
- voltage gated Na+ Channels open in response to a stimulus,the membrane voltage becomes more positive as thepositive ions rush inside the membrane
- depolarization originates at the Axon Hillock |
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Term
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Definition
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Term
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Definition
= Depolarization + Repolarization
- the electrical signal (impulse) that is propagated down theaxon |
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Term
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Definition
| - any electrical stimulus that is strong enough to initiate anaction potential |
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Term
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Definition
- the initial stimulus must reach threshold before an actionpotential is generated (there is no partial activation ofan action potential)
- this initial electrical stimulus will quickly dissipate ifthe threshold stimulus is not achieved |
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Term
| Events Associated With An Action Potential: |
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Definition
1. Threshold Stimulus is reached (-55mV)
2. Voltage Gated Sodium Channels open initiating Depolarization
3. Repolarization begins
4. Hyperpolarization occurs
5. RMP is restored by the Sodium-Potassium ATPase Pumps |
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Term
| Voltage Gated Sodium Channels open initiating Depolarization |
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Definition
- sodium rushes inside the axolemma
- the membrane voltage goes to 0 mV, then to approx. +30 mV(more positive inside the membrane)
- Voltage Gated Sodium Channels close at +30 mV |
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Term
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Definition
- with the Voltage Gated Sodium Channels closed, the action ofthe Sodium-Potassium ATPase Pumps begin to restore theproper ion concentrations along the axolemma
- the Voltage Gated Potassium Channels are now fully opened(they respond slowly to the Threshold Stimulus)
- the voltage across the axolemma becomes more negative (backto 0 mV, then to -90 mV) |
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Term
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Definition
- Hyperpolarization = membrane voltage is below RMP (-70 mV)
- this occurs because the Voltage Gated Potassium Channels areslow to close (positive charges are still leaking out ofthe axon) |
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Term
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Definition
| - The period of time in which an excitatory cell cannotgenerate another Action Potential |
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Term
| Absolute Refractory Period |
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Definition
- The Voltage Gated Sodium Channels need to reach a restingstate before they can be reactivated.
= The period of time from activation of Voltage Gated SodiumChannels until they reach a resting state. |
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Term
| Relative Refractory Period |
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Definition
| - During hyperpolarization of the axon membrane, a larger thanthreshold stimulus is needed to activate an actionpotential |
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Term
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Definition
Conduction
- as sodium rushes inside the axolemma, adjacent Voltage GatedChannels are activated (achieve Threshold Stimulus); theprocess of activating adjacent channels continues downthe axon towards the synapse |
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Term
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Definition
- Propagation of a nerve impulse in a step by stepdepolarization and repolarization of adjacent areas ofthe axolemma
- associated with nonmyelinated neurons |
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Term
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Definition
- the Action Potential is moved along the myelinated portionof the axolemma, passing from one Node of Ranvier to thenext until the impulse reaches the synapse
(the signal is passed along the myelinated regions via anionic current)
- associated with myelinated neurons |
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Term
| The effect of axon diameter. |
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Definition
| - The rate of nerve impulse transmission is determined by thediameter of the axon and the presence (or absence) ofmyelin |
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Term
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Definition
- myelinated
- largest diameter axon (5 - 20 micrometers)
- short absolute refractory period
- fastest nerve impulse transmission (27 - 280 mph) |
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Term
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Definition
- myelinated
- axon diameter is smaller than A fibers (2 - 3micrometers)
- absolute refractory period is longer than A fiber
- slower impulse transmission than A fiber (32 mph) |
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Term
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Definition
- unmyelinated
- smallest axon diameter (0.5 - 1.5 micrometers)
- longest absolute refractory period
- slowest impulse transmission (1 - 4 mph) |
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Term
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Definition
- ionic current spreads through Gap Junctions in adjacentcells
- are faster than chemical synapses
- ex. Cardiac muscle |
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Term
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Definition
1. A nerve impulse stimulates a vesicle (located in the axonterminus) to release neurotransmitter into the synapticcleft (i.e. the space between the Presynaptic andPostsynaptic Neurons)
2. The neurotransmitter diffuses across the synaptic cleft andinteracts with a specific receptor site on thePostsynaptic Neuron
- one way transfer of the signal
- the neurotransmitter must be deactivated shortly afterinteracting with the receptor
3. The Postsynaptic Neuron generates a graded potential that istransmitted to the Axon Hillock
- 2 primary effects on the Postsynaptic Neuron: |
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Term
| Excitatory Postsynaptic Potential (EPSP) |
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Definition
= depolarization (positive ions move into the Dendrite)
- this adds to the threshold stimulus (i.e. makes it morepositive) |
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Term
| Inhibitory Postsynaptic Potential (IPSP) |
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Definition
= hyperpolarization (negative ions flow in or positiveions flow out of the Dendrite)
- a stimulus that takes away from the threshold stimulus(i.e. makes it more negative) |
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Term
| Deactivation/Removal of Neurotransmitter from the SynapticCleft |
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Definition
- this prevents continuous stimulation of PostsynapticNeurons (End Organs)
1. Diffusion from the synaptic cleft
2. Enzymatic degradation
- ex. Acetylcholinesterase deactivating Acetylcholine
3. Uptake by cells
- reuptake by the secreting neuron or a glial cell |
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Term
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Definition
- occurs at the axon hillock
- integration of the EPSP's & IPSP's until a thresholdstimulus is reached (this will rapidly dissipate)
1. Spatial Summation
2. Temporal Summation |
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Term
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Definition
| - the build up of graded potentials caused by several synapticend bulbs releasing neurotransmitter |
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Term
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Definition
| - the build up of graded potentials caused by only onesynaptic end bulb releasing neurotransmitter in rapidsuccession |
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Term
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Definition
| - chemicals essential for transmission of across the synapticcleft |
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Term
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Definition
- can be excitatory or inhibitory
- deactivated by Acetylcholinesterase
ex. Alzheimer Disease
- progressive loss of the ability to reason and care forones self
- associated with high mortality
- caused by degeneration of ACh releasing neurons in theBrain |
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Term
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Definition
- Glutamate and Aspartate are excitatory
- Gamma Aminobutyric Acid (GABA) and Glycine are inhibitory |
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Term
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Definition
- modified amino acids
a. dopamine
b. serotonin
c. epinephrine, norepinephrine |
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Term
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Definition
- regulates skeletal muscle tone, movement, emotionalresponses
ex. Parkinson Disease
- associated with the progressive degeneration ofDopamine releasing neurons in the Brain
- patient develops tremors, slow and uncoordinatedmovements |
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Term
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Definition
- associated with sensory perception, mood control,temperature regulation, appetite, sleep induction
ex. Selective Serotonin Reuptake Inhibitor (SSRI)
- Prozac - allows serotonin to remain in thesynaptic cleft longer |
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Term
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Definition
| allows serotonin to remain in thesynaptic cleft longer |
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Term
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Definition
- thought to play a role in memory and learning
- is not produce in advance |
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Term
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Definition
- neurotransmitter 3 to 40 bonded amino acids
- can be excitatory or inhibitory
- often associated with controlling pain and modifyingneuronal activity
ex. Endorphins, Enkephalins, Substance P |
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Term
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Definition
| - the creation of new neurons from undifferentiated stem cells |
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Term
| Axon Repair in the Peripheral Nervous System |
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Definition
| - occurs in myelinated axons where the neurolemma in intact |
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Term
| Early effects of nerve repair: |
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Definition
- The cell body swells
- Wallerian Degeneration occurs - the portion to the axondistal to the injury degenerates
- the proximal portion of the axon degenerates to the nearestNode of Ranvier
- Nissl bodies become granular in appearance |
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Term
| Later effects of nerve repair: |
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Definition
- Schwann cells undergo mitosis to form a Regeneration tubeacross the injury site
- the axon is gradually reconstructed with in the sheath thatis left behind at a rate of 1 to 5 mm/day
- scar tissue in the "tube" of to wide of a gap will stopregeneration
- function is restored |
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