Lecture 1 Structure and Functions of Cells of the Nervous System Flashcards
Saltatory Conduction
- Conduction of action potentials by myelinated axons - The action potential appears to jump from one node of Ranvier to the next
Postsynaptic potentials
- Alterations in the membrane potential of a postsynaptic neuron, produced by the liberation of a neurotransmitter at the synapse
Binding Site
- The location on a receptor protein to which a ligand binds
Ligand (AKA Neurotransmitter)
- A chemical that binds with the binding site of a receptor
Dendritic Spine
- A small bud on the surface of a dendrite, with which a terminal button of another neuron forms a synapse
Presynaptic Membrane
- The membrane of a terminal button that lies adjacent to the postsynaptic membrane and through which the neurotransmitter is released
Postsynaptic membrane
- The membrane located on the dendrite of the neuron that receives the information
Synaptic Cleft
- The space between the presynaptic membrane and the postsynaptic membrane that is about 20nm wide
Synaptic Vesicle
- A small, hollow, beadlike structure found in the terminal buttons - Contains molecules of a neurotransmitter
Release Zone
- A region of the interior of the presynaptic membrane of a synapse to which synaptic vesicles attach and release their neurotransmitter into the synaptic cleft
Activation of receptors POSTSYNAPTIC RECEPTOR
- A receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter
Activation of receptors NEUROTRANSMITTER-DEPENDENT ION CHANNEL
- An Ion channel that opens when a molecule of a neurotransmitter binds with a postsynaptic receptor
Activation of receptors IONOTROPIC RECEPTOR
- A receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site
Activation of receptors METABOTROPIC RECEPTOR
- A receptor that contains a binding site for a neurotransmitter - Activates an enzyme that begins a series of events, opening an Ion channel elsewhere in the membrane of the cell when a molecule of the neurotransmitter attaches to the binding site
Postsynaptic Potentials EXCITATORY POSTSYNAPTIC POTENTIAL (EPSP)
- An excitatory depolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button
Postsynaptic Potentials INHIBITORY POSTSYNAPTIC POTENTIAL (IPSP)
- An inhibitory hyper polarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button
Termination of postsynaptic potentials REUPTAKE
- The reentry of a neurotransmitter just liberated by a terminal button back through its membrane, thus terminating the postsynaptic potential
Termination of postsynaptic potentials ENZYMATIC DEACTIVATION
- The destruction of a neurotransmitter by an enzyme after its release, for example, the destruction of acetylcholine by acetylcholinesterase
Termination of postsynaptic potentials ACETYLCHOLINE (Ach)
- A neurotransmitter found in the brain, spinal cord, and parts of the peripheral nervous system - Responsible for muscular contraction - Active in memory, attention, and muscle control
Termination of postsynaptic potentials ACETYLCHOLINESTERASE (AChE)
- The enzyme that destroys acetylcholine soon after it is liberated by the terminal buttons, thus terminating the postsynaptic potential
Effect of Postsynaptic potential
- Neural Integration
Neural Integration
- The process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron
Autoreceptor
- A receptor molecule located on a neuron that responds to the neurotransmitter released by that neuron
Heteroreceptor
- The receptor on the receiving neuron
Autoreceptors have a variety of functions
- Regulate the internal processes of the cell - Regulate synthesis of the neurotransmitter - Regulate the release of a neurotransmitter - Generally serve to inhibit the activity of a transmitter
Axoaxonic Synapses PRESYNAPTIC INHIBITION
- The action of a presynaptic terminal button in an axoaxonic synapse - Reduces the amount of neurotransmitter released by the postsynaptic terminal button
Axoaxonic Synapses PRESYNAPTIC FACILITATION
- The action of a presynaptic terminal button in an axoaxonic synapse - Increases the amount of neurotransmitter released by the postsynaptic terminal button
Non-synaptic Chemical Communication NEUROMODULATORS
- A naturally secreted substance that acts like a neurotransmitter except that it is nor restricted to the synaptic cleft but diffuses through the extracellular fluid
Non-synaptic Chemical Communication PEPTIDE
- A chain of amino acids joined together by peptide bonds. Most neuromodulators, and some hormones, consist of peptide molecules
Non-synaptic Chemical Communication HORMONE
- A chemical substance that is released by an endocrine gland and that has effects on target cells in other organs
Non-synaptic Chemical Communication ENDOCRINE GLAND
- A gland that liberates its secretions into the extracellular fluid around capillaries and hence into the bloodstream
drug class mantra
- There are classes of drugs and the classes are determined by the mechanism of action
Six primary neurotransmitters
- Gaba - Norepinephrine - glutamate - Dopamine - Seritonin - Acetylcholine
Acetylcholine is broken down by?
- Acetylcholinesterase
Four most common electrolytes
- Sodium + - Potasium + - Chloride - CO2
If it ends in “ase” its most likely a?
- Enzyme
Reversed Prompt
- Comprised of the Brain and Spinal Cord - Encased WITHIN the Skull and Spinal column
Central Nervous System (CNS)
Reversed Prompt
- Comprised of Nerve tissue located OUTSIDE of the brain and Spinal cord
Peripheral Nervous System (PNS)
Reversed Prompt
- Detects changes in the external OR internal environment and sends information about these changes to the CNS
Sensory Neuron
Reversed Prompt
- Located WITHIN the CNS that controls the contraction of a muscle or the secretion of a gland
Motor Neuron
Reversed Prompt
- Located ENTIRELY WITHIN the CNS
Interneuron
Reversed Prompt
- Cell body of a neuron, which contains the nucleus
Neuron Basic Structure SOMA or Cell Body
Reversed Prompt
- A branched treelike structure attached to the soma of a neuron - Receives info from the terminal button of other neurons
Neuron Basic Structure DENDRITE
Reversed Prompt
- The long thin cylindrical structure that conveys info from the soma of a neuron to its terminal button
Neuron Basic Structure AXON
Reversed Prompt
- A junction between the terminal button of an axon and the membrane of another neuron
Neuron Basic Structure SYNAPSE
Reversed Prompt
- A neuron with one axon and many dendrites attached to its soma
Multipolar Neurons
Reversed Prompt
- A Neuron with one axon and one dendrite attached to its soma
Bipolar Neurons
Reversed Prompt
- A neuron with one axon attached to its soma - The axon divides, one branch receiving sensory info and the other sending the info into the CNS
Unipolar Neurons
Reversed Prompt
- The bud at the end of a branch of an axon - Forms synapses with another neuron and sends info to that neuron
Neuron Basic Structure TERMINAL BUTTON
Reversed Prompt
- A chemical that is released by a terminal button - Has an excitatory or inhibitory effect on another neuron
Neuron Basic Structure NEUROTRANSMITTER
Reversed Prompt
- A structure consisting principally of lipid molecules that defines the outer boundaries of a cell and also constitutes many of the cell organelles
Internal Structure MEMBRANE
Reversed Prompt
- The viscous, dimi-liquid substance contained in the interior of a cell
Internal Structure CYTOPLASM
Reversed Prompt
- An organelle that is responsible for extracting energy from nutrients
Internal Structure MITOCHONDRIA
Reversed Prompt
- A molecule of prime importance to cellular energy metabolism - Its breakdown liberates energy
Internal Structure ADENOSINE TRIPHOSPHATE (ATP)
Reversed Prompt
- A structure in the central region of a cell, containing the nucleolus and chromosomes
Internal Structure NECLEUS
Reversed Prompt
- A strand of DNA, with associated proteins, found in the nucleus and carries genetic info
Internal Structure CHROMOSOME
Reversed Prompt
- A long complex macromolecule consisting of two interconnected helical strands, along with associated proteins, strands of DNA constitute the chromosomes
Internal Structure DEOXYRIBONUCLEIC ACID (DNA)
Reversed Prompt
- The functional unit of the chromosome, which directs synthesis of one or more proteins
Internal Structure GENE
Reversed Prompt
- Formed of microtubules and other protein fibers, linked to each other and forming a cohesive mass that gives a cell its shape
Internal Structure CYTOSKELETON
Reversed Prompt
- A Molecule that controls a chemical reaction, combining two substances or breaking a substance into two parts
Internal Structure ENZYME
Reversed Prompt
- A long strand of bundles of protein filaments arranged around a hollow core - A part of the cytoskeleton and involved in transporting substances from place to place within the cell
Internal Structure MICROTUBULE
Reversed Prompt
- An active process by which substances are propelled along microtubules that run the length of the axon
Internal Structure AXOPLASMIC TRANSPORT
Reversed Prompt
- Also known as neuroglia or “neural glue” The supporting cells of the CNS
Supporting Cells GLIAL CELLS
Reversed Prompt
- A glial cell that provides support to neurons of the CNS - Provides nutrients and other substances - Regulates the chemical composition of the extracellular fluid
Supporting Cells ASTROCYTE or “STAR CELL”
Reversed Prompt
- The process by which cells engulf and digest other cells or debris caused by cellular degeneration
Phagocytosis
Reversed Prompt
- A type of glial cell in the CNS that forms myelin sheaths
Oligodendrocyte
Reversed Prompt
- A sheath that surrounds axons and insulates them, preventing messages from spreading between adjacent axons
Myelin Sheath
Reversed Prompt
- A naked portion of a myelinated axon, between adjacent oligodendrocytes or Schwann cells
Node of Ranvier
Reversed Prompt
- The smallest glial cells - act as phagocytes and protect the brain from invading microorganisms
Microglia
Reversed Prompt
- A cell in the PNS that is wrapped around a myelinated axon, providing one segment of its myelin sheath
Schwann Cell
Reversed Prompt
- Paul ehrlich injected blue dye into the bloodstream of animals and found dye everywhere except in the brain and spinal cord - Regulates the chemicals that can enter the CNS from the blood - Helps the CNS maintain the proper composition of fluids inside and outside the neurons
Features of the Blood-Brain Barrier BBB
Reversed Prompt
- A semipermeable barrier between the blood and the brain produced by cells in the walls of the brain’s capillaries
Blood-brain barrier
Reversed Prompt
- A region of the medulla where the blood-brain barrier is weak - Poisons can be detected there and can initiate vomiting
Area Postrema
Reversed Prompt
- A conductive medium that can be used to apply electrical stimulation and record electrical potentials
Electrode
Reversed Prompt
- A very fine electrode, generally used to record activity of individual neurons
Microelectrode
Reversed Prompt
- The electrical charge across a cell membrane; the difference in electrical potential inside and outside the cell
Membrane Potential
Reversed Prompt
- A laboratory instrument that is capable of displaying a graph of voltage as a function of time on the face of a cathode ray tube
Oscilloscope
Reversed Prompt
- Resting Membrane potential - Action potential
Axons have two basic electrical potentials
Reversed Prompt
- Depolarization - Hyperpolarization - Threshold of Excitation
The Membrane Potential can change
Reversed Prompt
-The resting potential of a neuron when it is not being altered by excitatory or inhibitory postsynaptic potentials; approximately -70mV in the giant squid axon
Resting Membrane Potential
Reversed Prompt
-Reduction (toward zero) of the membrane potential of a cell from its normal resting potential
Depolarization
Reversed Prompt
- An increase in the membrane potential of a cell, relative to the normal resting potential
Hyperpolarization
Reversed Prompt
- The brief electrical impulse that provides the basis for conduction of information along an axon
Action Potential
Reversed Prompt
- The value of the membrane potential that must be reached to produced an action potential
Threshold of Excitation
Reversed Prompt
- Movement of molecules from a region of high concentration to regions of low concentration
The force of Diffusion DIFFUSION
Reversed Prompt
- An aqueous solution of a material that ionizes a soluble acid, base, or salt
The force of Electrostatic Pressure ELECTROLYTE
Reversed Prompt
- A charged molecule - Cations are positively charged - Anions are negatively charged
The force of Electrostatic Pressure ION
Reversed Prompt
- The attractive force between atomic particles charged with opposite signs or - The repulsive force between two atomic particles charged with the same sign
Electrostatic Pressure
Reversed Prompt
- Sodium (+) - Potasium (+) - Chloride (-) - CO2 (-)
Most common Electrolytes and their charge
Reversed Prompt
- The fluid contained within cells
Intracellular Fluid
Reversed Prompt
- Body fluids located outside cells
Extracellular Fluid
Reversed Prompt
- A protein found in the membrane of all cells that extrudes sodium ions
Sodium-Potassium Transporter
Reversed Prompt
- A specialized protein molecule that permits specific ions to enter or leave the cell
Ion Channel
Reversed Prompt
- An ion channel that opens or closes according to the value of the membrane potential
Voltage-dependent Ion Channel
Reversed Prompt
- The principle that once an action potential is triggered in an axon, it is propagated without decrement to the end of the fiber
All-or-none Law
Reversed Prompt
- The principle that variations in the intensity of a stimulus or other information being transmitted in an axon are represented by variations in the rate at which that axon fires
Rate Law
Reversed Prompt
- Conduction of action potentials by myelinated axons - The action potential appears to jump from one node of Ranvier to the next
Saltatory Conduction
Reversed Prompt
- Alterations in the membrane potential of a postsynaptic neuron, produced by the liberation of a neurotransmitter at the synapse
Postsynaptic potentials
Reversed Prompt
- The location on a receptor protein to which a ligand binds
Binding Site
Reversed Prompt
- A chemical that binds with the binding site of a receptor
Ligand (AKA Neurotransmitter)
Reversed Prompt
- A small bud on the surface of a dendrite, with which a terminal button of another neuron forms a synapse
Dendritic Spine
Reversed Prompt
- The membrane of a terminal button that lies adjacent to the postsynaptic membrane and through which the neurotransmitter is released
Presynaptic Membrane
Reversed Prompt
- The membrane located on the dendrite of the neuron that receives the information
Postsynaptic membrane
Reversed Prompt
- The space between the presynaptic membrane and the postsynaptic membrane that is about 20nm wide
Synaptic Cleft
Reversed Prompt
- A small, hollow, beadlike structure found in the terminal buttons - Contains molecules of a neurotransmitter
Synaptic Vesicle
Reversed Prompt
- A region of the interior of the presynaptic membrane of a synapse to which synaptic vesicles attach and release their neurotransmitter into the synaptic cleft
Release Zone
Reversed Prompt
- A receptor molecule in the postsynaptic membrane of a synapse that contains a binding site for a neurotransmitter
Activation of receptors POSTSYNAPTIC RECEPTOR
Reversed Prompt
- An Ion channel that opens when a molecule of a neurotransmitter binds with a postsynaptic receptor
Activation of receptors NEUROTRANSMITTER-DEPENDENT ION CHANNEL
Reversed Prompt
- A receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site
Activation of receptors IONOTROPIC RECEPTOR
Reversed Prompt
- A receptor that contains a binding site for a neurotransmitter - Activates an enzyme that begins a series of events, opening an Ion channel elsewhere in the membrane of the cell when a molecule of the neurotransmitter attaches to the binding site
Activation of receptors METABOTROPIC RECEPTOR
Reversed Prompt
- An excitatory depolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button
Postsynaptic Potentials EXCITATORY POSTSYNAPTIC POTENTIAL (EPSP)
Reversed Prompt
- An inhibitory hyper polarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button
Postsynaptic Potentials INHIBITORY POSTSYNAPTIC POTENTIAL (IPSP)
Reversed Prompt
- The reentry of a neurotransmitter just liberated by a terminal button back through its membrane, thus terminating the postsynaptic potential
Termination of postsynaptic potentials REUPTAKE
Reversed Prompt
- The destruction of a neurotransmitter by an enzyme after its release, for example, the destruction of acetylcholine by acetylcholinesterase
Termination of postsynaptic potentials ENZYMATIC DEACTIVATION
Reversed Prompt
- A neurotransmitter found in the brain, spinal cord, and parts of the peripheral nervous system - Responsible for muscular contraction - Active in memory, attention, and muscle control
Termination of postsynaptic potentials ACETYLCHOLINE (Ach)
Reversed Prompt
- The enzyme that destroys acetylcholine soon after it is liberated by the terminal buttons, thus terminating the postsynaptic potential
Termination of postsynaptic potentials ACETYLCHOLINESTERASE (AChE)
Reversed Prompt
- Neural Integration
Effect of Postsynaptic potential
Reversed Prompt
- The process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron
Neural Integration
Reversed Prompt
- A receptor molecule located on a neuron that responds to the neurotransmitter released by that neuron
Autoreceptor
Reversed Prompt
- The receptor on the receiving neuron
Heteroreceptor
Reversed Prompt
- Regulate the internal processes of the cell - Regulate synthesis of the neurotransmitter - Regulate the release of a neurotransmitter - Generally serve to inhibit the activity of a transmitter
Autoreceptors have a variety of functions
Reversed Prompt
- The action of a presynaptic terminal button in an axoaxonic synapse - Reduces the amount of neurotransmitter released by the postsynaptic terminal button
Axoaxonic Synapses PRESYNAPTIC INHIBITION
Reversed Prompt
- The action of a presynaptic terminal button in an axoaxonic synapse - Increases the amount of neurotransmitter released by the postsynaptic terminal button
Axoaxonic Synapses PRESYNAPTIC FACILITATION
Reversed Prompt
- A naturally secreted substance that acts like a neurotransmitter except that it is nor restricted to the synaptic cleft but diffuses through the extracellular fluid
Non-synaptic Chemical Communication NEUROMODULATORS
Reversed Prompt
- A chain of amino acids joined together by peptide bonds. Most neuromodulators, and some hormones, consist of peptide molecules
Non-synaptic Chemical Communication PEPTIDE
Reversed Prompt
- A chemical substance that is released by an endocrine gland and that has effects on target cells in other organs
Non-synaptic Chemical Communication HORMONE
Reversed Prompt
- A gland that liberates its secretions into the extracellular fluid around capillaries and hence into the bloodstream
Non-synaptic Chemical Communication ENDOCRINE GLAND
Reversed Prompt
- There are classes of drugs and the classes are determined by the mechanism of action
drug class mantra
Reversed Prompt
- Gaba - Norepinephrine - glutamate - Dopamine - Seritonin - Acetylcholine
Six primary neurotransmitters
Reversed Prompt
- Acetylcholinesterase
Acetylcholine is broken down by?
Reversed Prompt
- Sodium + - Potasium + - Chloride - CO2
Four most common electrolytes
Reversed Prompt
- Enzyme
If it ends in “ase” its most likely a?