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88 Cards in this Set
- Front
- Back
The three overlapping functions of the nervous system.
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1. Gathering SENSORY INPUT.
2. Integrating the information, INTEGRATION. 3. Causing a response, MOTOR OUTPUT. |
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The Nervous system is divided into the ________ and the __________ systems.
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Peripheral and Central systems.
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The two divisions of the peripheral nervous system.
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The sensory (afferent) and the motor (efferent) systems.
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The sensory (afferent) system.
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Consists of nerve fibers that carry impulses to the CNS. The input comes from sensory nerves in the skin and visceral organs.
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The motor (efferent) system.
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Consists of impulses coming from the CNS to the effector organs (muscles and glands).
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The two divisions of the peripheral nervous system.
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1. Motor (efferent)
2. Sensory (afferent) |
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Autonomic system.
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Comprised of visceral nerve fibers that regulate activity of the smooth muscles, heart, and glands.
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Somatic system.
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Comprised of somatic nerve fibers (axons) that conduct impulses from the CNS to skeletal muscle.
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This system is also called the voluntary system.
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somatic nervous system is also called this.
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The system is also called the involuntary system.
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autonomic nervous system is also called this.
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The autonomic nervous system is divided into these two divisions.
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1. Sympathetic
2. Parasympathetic |
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The two major cell types present in the nervous system.
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1. Neurons
2. Glial Cells |
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The excitable cell that transmits electrical impulses.
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Neurons.
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The supporting cells of the nervous system.
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Glial cells.
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The 6 types of glial cells found in the nervous sytem.
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1. Astrocytes
2. Microglia 3. Ependymal cells 4. Oligodendrocytes 5. Satellite cells 6. Schwann cells |
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The glial cells founds in the CNS.
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1. Oligodendrocytes
2. Ependymal cells 3. Microglia 4. Astrocytes |
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The glial cells found in the PNS.
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1. Satellite cells
2. Schwann cells |
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These nervous system cells surround neuron bodies of the PNS.
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Satellite cells.
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The nervous system cells form myrlin sheaths around the larger nerve fibers.
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Schwann cells.
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These PNS cells are vital to regeneration and proper nerve signal transduction.
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Schwann cells.
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The ratio of glial to neuron cells.
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_____ cells out number neurons 10:1 and make up half the brain's mass.
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These are star shaped cells. Most abundant and versatile glial cell.
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Astrocytes.
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These cells control the chemical environment, mop up leaked k+ ions and recycle neurotransmitters.
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Astrocytes.
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These cells anchor neurons and their capillaries. They secrete chemicals that help young neurons make the right connections and help determine capillary permeability.
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Astrocytes.
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These cells are connected by gap junctions, communicate by calcium sparks, and influence neurons so that they help the info processing in the brain.
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Astrocytes.
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These are small, ovoid cells with thorny processes.
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Microglia.
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These cells monitor neuron health. They act like immune cells and macrophages in the brain. They can be migratory.
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Microglia.
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These cells range in shape from sqaumous to columnar and many are ciliated.
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Ependymal cells.
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These cells line the central cavity of the brain and spinal cord where they are a fairly permeable barrier between the cerebrospinal fluid and the cells of the CNS. Their cilia beating helps to circulate CSF.
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Ependymal cells.
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These are branching cells but have fewer processes than other cells. They produce myelin sheaths around thicker neurons of the CNS.
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Oligodendrocytes.
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Neurons.
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These nerve cells have extreme longevity. Given good nutrition, these cells function a lifetime. They are amitotic and have a high metabolic rate.
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amitotic.
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Means cells do not divide.
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Clusters of cell bodies in the CNS are called _________.
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Nuclei.
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Clusters of cell bodies along the nerves in the PNS are called _________.
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Ganglia.
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Bundles of neuron processes in the CNS are called _______.
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Tracts.
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Bundles of neuron processes in the PNS are called _______.
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nerves.
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The two types of neuron processes.
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Dendrites and axons.
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Dendrites.
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The receptive region of neurons that gathers input.
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Axon.
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The part of neurons that carries information away.
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Two ways of classifying neurons.
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1. Structure (multipolar, bipolar, unipolar)
2. Function (sensory, motor) |
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Four gate types of membrane ion channels.
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1. Voltage-gated.
2. Chemically (ligand) gated. 3. Mechanically gated. 4. Leakage (non-gated). |
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Voltage-gated membrane ion channel.
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These channels open in response to changes in the membrane potential.
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Chemically (ligand) gated membrane ion channel.
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These channels open when a ligand binds to them.
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Mechanically gated membrane ion channel.
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These channels open physically deformed. (seen in sensory receptors for touch)
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Leakage (non-gated) membrane ion channels.
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These channels are always open.
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The resting membrane potential for most cells is _____.
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- 70 is the ___________ for most cells.
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The cell is polarized when it is at it's ______________.
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A cell is ___________ when it is at it's resting membrane potential (-70).
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Two types of membrane potentials to send signals.
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1. Graded potentials
2. Action potentials |
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Graded potentials.
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Used for sending incoming messages over a short distance.
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Action potentials.
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Long distance signals used by axons.
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Depolarization.
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A reduction in membrane potential. The inside of the cell becomes less negative. (moves closer to zero)
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Hyperpolarization.
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When the inside of the cell becomes more negative. (makes the cell inhibitory to function)
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Short-lived localized changes in the membrane potential that can either be depolarizing or hyperpolarizing. Essential to triggering action potentials.
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Graded potentials.
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The states of an action potentials.
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1. Resting state.
2. Depolarizing phase. 3. Repolarizing phase. 4. Hyperpolarizing phase. |
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The relative refractory period occurs during the _________ phase.
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The _____________ period occurs during the hyperpolarization phases.
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Action potentials can occur in nerves only if ________________.
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Another _________ can occur in nerves only if the started AP is completed and the cell has returned to it's resting potential.
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The speed of transmission of an action potential signal.
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The conduction velocity.
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The conduction velocity is determined by the:
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1. Axon diameter (larger=faster)
2. Myelination degree (no myelin sheath=slow conduction velocity) |
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Saltatory conduction.
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In myelinated axons where AP are triggered at nodes and jump from node to node along the axon.
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Multiple Sclerosis.
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An autoimmune disease that causes demyelination. The destoryed myelin sheaths result in hardened leasions called 'scleroses.'
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Symptoms of MS.
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Causes blindness, muscle control problems including weakness and paralysis, speech problems, and urinary incontinence.
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Treatment of MS.
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Treated with Copaxone. helps with symptoms but doesn't stop the disease.
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Three ways to classify nerve fibers.
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1. Degree of myelination.
2. Diameter. 3. Conduction speed. |
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Group A Fibers.
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Have the largest diameter, thick myelin sheaths, and the highest conduction velocity.
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Group B Fibers.
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Intermediate diameter, lightly myelinated fibers, transmit at 15 s/mm.
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Group C Fibers.
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The fibers with the smallest diameter, unmyelated, have the slowest conduction rate.
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Group ___ Fibers are mostly somatic sensory and motor fibers serving skin, joints, and skeletal muscles.
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Group A fibers are mostly ________________.
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The junction between neurons or neurons and their effectors.
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Synapse.
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Synapses can be ___ or ____ and have a ______ side and _____ side.
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electrical or chemical, have a postsynaptic and presynaptic side.
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First event of depolarization at a chemical synapse.
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Arrival of depolarization wave. Voltage-gated Ca2+ channels open to let Ca2+ enter axon terminal.
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Second event of depolarization at a chemical synapse.
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Synaptic vesicles fuse with the presynaptic membrane. Neurotransmitter is released into the synaptic cleft.
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Third event of depolarization at a chemical synapse.
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Neurotransmitter fuses across synaptic cleft and fuses to postsynaptic membrane.
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Fourth event od depolarization at a chemical synapse.
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Binding of neurotransmitter opens ion channels in postsynaptic membrane. This causes a graded potential.
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Fifth event of depolarization at a chemical synapse.
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Neurotransmitter is quickely destroyed by enzymes at synapse or taken back to presynaptic terminal. Depletion of neurtotransmitters close ion channels and terminate synaptic response.
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EPSP's.
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Excitatory postsynaptic potentials. Local graded depolarization response that helps to trigger action potentials.
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IPSP's.
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Inhibitory postsynaptic potentials. Inhibits the ability to produce action potentials by hyperpolarizing the cell locally. Graded response.
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Direct response of neurotransmitters.
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Response of neurotransmitters involving rapid and open ion channels.
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Neurotransmitters can be _______ or ________ and can act through ________ or _______ mechanisms.
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Excitatory or Inhibatory, Direct or indirect.
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Indirect response of neorotransmitters.
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Usually involve release of neuromodulators and G-protein signaling cascades. Slower responses.
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Serial processing.
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The whole system works in a predictable all or nothing response. (reflexes)
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Reflexes.
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Rapid and automatic responses to a particular stimuli.
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Reflexes occur over neural pathways called _________.
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Reflex arcs.
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Important for higher functions where the stimuli is processed in the CNS and a response or series of responses are triggered.
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Parallel Processing.
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The two receptors for ACh.
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1. Nicotinic ACh receptors. (on skeletal muscles, autonomic ganglia, and in CNS)
2. Muscarinic ACh receptors. (On visceral effectors and in the CNS) |
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Subthreshold, No Summation.
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The EPSP graded response does not meet theshold and no AP is triggered.
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Spatial Summation.
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More then one EPSP graded respose and sent to the cell at the same time, an AP is triggered because the threshold is met.
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Temporal Summation.
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A EPSP graded respose is sent before the first EPSP graded response finished so the threshold is met and the AP is triggered.
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Spatial summations of EPSP and IPSP.
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When an IPSP and an EPSP are triggered at the same time, they cancel eachother out and nothing happens.
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