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Mr charles psyc ch3
psychology kelat chapter 3
Question | Answer |
---|---|
An active neuron has an internal charge of _______ called resting potential | -70 mV |
An active neuron has an external charge of _______ called resting potential | +70 mV |
resting potential is generated by the uneven distribution of 4 major ions. | Potassium, Sodium, Chloride, Anions |
If channels open, Na+ would flood inside due to excessive positive charge of _____ on the outside and negative –70 mV on the inside. | Na+ |
The movement of the ions is governed by 2 forces? | oElectrostatic gradient (electrostatic) oConcentration gradient |
cross freely through channels that are always open. | Oxygen, CO2 , Urea, H2O |
Myelin Sheath and Saltatory Conduction | the jumping of action potentials from node to node |
Nodes of Ranvier | gaps between myelin sheath |
Myelin sheath allows | signal to skip over 99% of axion, 100 times faster with sheath, Saltatory conduction is 120 meters per second |
Brief gap between two neurons is called? | the synapse or synaptic gap or synaptic cleft (axon to dendrite) |
The preceding neuron is called? | presynaptic |
The later neuron is called? | postsynaptic |
The post synaptic membrane may be? | a dendrite, a soma, or a rarely even an axon. |
When action potential reaches terminal bouton... | there is a Catacholamine (Ca++) that signals the release of neurotransmitters (NTs) from the vesicles in which they are contained. |
The NTs then diffuse across the cleft | and bind to receptors on the postsynaptic membrane |
The NT diffusion can be either: | Depolarization or Hyperpolarization |
Depolarization | influx of Na+ (Excitatory Postsynaptic Potential-EPSP) |
Hyperpolarization | an outflow of K+ or an influx of Cl- (Inhibitory Postsynaptic Potential-IPSP) |
How are NTs removed from the Synapse? | Diffusion (rare, Metabolism by enzymatic degradation-enzyme protein which changes rate of chemical reaction, destruction chemically of a chemical reaction, cuts in half or adds something to it. Recycle NT back into presynaptic terminal through re-uptake. |
What is Temporal Summation? | repeated stimuli within a brief time have a cumulative effect. Page in notes of diagram |
Postsynaptic Neuron | the cell that receives the message. |
Presynaptic Neuron | the neuron that delivers the synaptic transmission. |
Unlike action potentials, which are always depolarizations, graded potentials... | may be either depolarizations (excitatory) or hyperpolarizations (inhibitory). A graded depolarization is known as an Excitatory postsynaptic potential (EPSP). |
Spatial Summation | -several synaptic inputs originating from separate locations combine their effects on a neuron. |
Inhibitory Postsynaptic Potential (IPSP) | temporary hyperpolarization membrane occurs when synaptic input opens gates for K+ ions to leave (carry a positive charge) or Cl- to enter the cell (carry negative charge)Inhibition more than excitation active brake suppresses excitation. |
Spontaneous Firing Rate | a periodic production of action potentials even without synaptic input. Relationship among EPSP and IPSP |
Neurotransmitters | are chemicals, at the synapse, one neuron releases chemicals that affect a second neuron. |
What are the types of Neurotransmitters? | *Amino Acids-contain amine group (NH2) •Peptides-chains amino acids (long polypeptide; longer protein •Acetylcholine (1-member “familyâ€) similar to amino acid, except NH2 replaced by N(CH3)3 •Monoamines-NTs contain 1 amine group (NH2), metabol |
Amino Acids | acids containing an amine group (NH2) |
Peptides | chains of amino acids (a long chain of amino acids is called a polypeptide; a still loner chain is a protein. The distance among peptides, polypeptide, and protein are not firm. |
Acetylcholine | (a one-member “familyâ€) a chemical similar to an amino acid, except that the NH2 group has been replaced by an N(CH3)3 group. |
Monoamines | neurotransmitters containing one amine group (NH2), formed by a metabolic change in certain amino acids |
Purines | category of chemicals including adenosine and several of its derivatives |
Gases | nitric oxide (NO) a gas released by many small local neurons and possibly others |
Catecholamines | (epinephrine, norepinephrine, and dopamine) closely related compounds because they contain a catechol group and an amine group. |
Agonistic | will have action equal or like normal neurotransmitter NT at that synapse. |
Antagonistic | if chemical blocks action of neurotransmitter NT, can be IPSP or EPSP |
Direct Action | if action is ON postsynaptic receptor direct |
Indirect Action | |
Brain works mainly with _________ to block signals. | IPSP (Inhibitory PostSynaptic Potential |
What are the types of Neurotransmitters? | Biological Amines (amino acids and their derivatives) Monoamines (only has one amine group - Nitrogen (NH2) Catecholamines – Dopamine, Norepinephrine, Epinephrine Endolomines |
How to tell an enzyme: | First part of word is what the chemical will work on - primary substrate, Middle part of word tells what it does chemically, Suffix – ASE |