Term
| List the three functional classes of neurons, and explain how they differ structurally and functionally. |
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Definition
Sensory afferents carry messages from sensory receptors to the CNS, their cell bodies are located close to the CNS.
Interneurons are completley contained within the CNS and are often extensivley branched.
Efferents carry signals from the CNS to the effectors. They have short, branched dentrites and long axons |
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Term
| Where do neurohormones-secreting neurons terminate? |
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Definition
| Neurons that secrete neurohormones terminate close to blood vessels so that the neurohormones can enter the circulation. |
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Term
| What is the difference between a nerve and a neuron? |
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Definition
| A neuron is a single nerve cell. A nerve is a bundle of axons from many neurons. |
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Term
| What is the primary function of myelin? |
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Definition
| To insulate axon membranes |
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Term
| What is the primary function of Microglia? |
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Definition
| Scavenger cells in the CNS |
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Term
| What is the primary function of Ependymal cells? |
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Definition
| From epithelial barriers between fluid compartments of the CNS |
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Term
| Name the two glial cell types that form myelin. How do they differ from each-other? |
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Definition
Shwann cells are in the PNS, each schwann cell forms myelin around a small portion of one axon.
Oligodendrocytes are in the CNSm and one oligodendrocyte forms myelin around axons of several neurons |
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Term
| Would a cell with a resting membrane potential of -70mV depolarize or hyperpolarize when the cell becomes more permeable to Ca2+? |
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Definition
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Term
| Would a cell with a resting membrane potential of -70mV depolarize or hyperpolarize when the cell becomes less permeable K+ |
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Definition
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Term
| Would the cell membrane depolarize or hyperpolarize if a small amount of Na+ leaked into the cell? |
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Definition
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Term
| What is the difference between conductance and conduction in neurons? |
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Definition
| Conductance refers to the movement of ions across a cell membrane. Conduction is the rapid, undiminished movement of an electrical signal down the axon of a neuron. |
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Term
| If you put ouabain an inhibitor of the Na+ K+ pump, on a neuron and then stimulate the neuron repeatedly, what do you expect to happen to action potentials generated by that neuron? |
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Definition
| There is no immediate effect, but they diminsh with repeated stimulation and eventually disappear. |
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Term
| When Na+ channel gates are resetting, is the activation gate opening or closing? Is the inactivation gate opening or closing? |
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Definition
| During resetting, the activation gate is closing and the inactivation gate is opening |
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Term
| Why are axon terminals sometimes called "biological transducers"? |
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Definition
| Axon terminals convert (transduce) the electric action potential signal into a chemical neurotransmitter signal |
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Term
| Somatic motor neurons control ____________, and _____________ neurons control smooth and cardiac muscles, glands, and some adipose tissue. |
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Definition
| skeletal muscles; autonomic |
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Term
| Autonomic neurons are classified as either _________________ or _________________ neurons. |
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Definition
| Sympathetic; parasympathetic |
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Term
| Name the two primary cell types found in the nervous system. |
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Definition
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Term
Arrange the following events in the proper sequence
a) Efferent neuron reaches threshold and fires AP
b) Afferent neuron reaches threshold and fires AP
c)Effector organ responds by preforming output
d)Integrating centre reaches decision about response
e)Sensory organ detects change in the enviroment |
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Definition
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Term
| List 3 ways neurotransmitters are removed from the synapse |
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Definition
| enzymatic degradation, reabsorption, and diffusion |
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Term
| B lymphocytes are activated by the activities of ____________ |
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Definition
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Term
| Based on your knowledge of the ABO blood types, which of the following blood type is considered the universal donor (i.e. can give blood to anybody, regardless of blood type) and why? |
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Definition
| type O, because the red blood cells don't have A or B antigens and can't start an immune reaction |
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Term
| During a bacterial infection (i.e. an extracellular pathogen), you would expect to see increased numbers of ___________ in the blood. |
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Definition
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Term
| What happens during the rising phase of action potential? |
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Definition
| Na+ moves down its electrochemical gradient |
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Term
| In order for a neuron to change from the absolute refractory period to the relative refractory period, a majority of the neuron's sodium channels must have |
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Definition
| activation gates closed and inactivation gates open. |
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Term
| An excitatory graded potential will occur if |
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Definition
| more sodium channels open |
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Term
| In order to secrete more molecules of neurotransmitter, the presynaptic cell would have to |
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Definition
| send action potentials at a higher frequency |
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Term
| Inhibitory neurotransmitters of the CNS may act by opening _____________ channels. |
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Definition
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Term
| When a second excitatory post-synaptic potential arrives at a single synapse before the effects of the first have disappeared, what occurs? |
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Definition
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Term
| Tom suffers a stroke that leaves him partially paralyzed on his right side. What type of glial cell would you expect to find in increased numbers in the damaged region of the brain? |
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Definition
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Term
| If K+ leaves the cell, what type of graded potential would there be? |
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Definition
| hyperpolarizing & inhibitory |
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Term
| A larger stimulus means that the axon will have what effect on action potenials |
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Definition
| produce more frequent action potentials |
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Term
| When action potentials arrive at the axon terminal at a higher frequency, how is neurotransmitter release affected? |
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Definition
| More molecules are released into the synapse |
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Term
| A drug is more likely to have an effect on the brain if it is |
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Definition
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Term
| The blood-brain barrier is formed by |
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Definition
| cells lining tiny blood vessels in the brain. |
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Term
| The dorsal root ganglia contain |
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Definition
| cell bodies of sensory neurons. |
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Term
| The major consumer of ATP in the CNS is |
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Definition
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Term
| When should you expect that sleep-walking could occur? |
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Definition
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Term
| A person hears some words and tries to repeat them. They come out as gibberish. If that person realizes it sounds like gibberish, what part of the brain is probably damaged. |
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Definition
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Term
| Nervous system cells that are specialized to use action potentials to transmit information are called __________. |
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Definition
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Term
| The chemical messengers released into synapses are called __________. |
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Definition
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Term
| The portion of the nervous system that directly controls skeletal muscles is the __________. |
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Definition
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Term
| Information arriving at the central nervous system is referred to as __________. |
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Definition
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Term
| Nerve and muscle cells are classified as excitable tissues because they __________. |
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Definition
| propagate electrical signals |
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Term
| The myelin sheaths that surround axons in the CNS are formed by __________. |
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Definition
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Term
| Slow axonal transport refers to __________ down the length of the axon away from the cell body (soma). |
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Definition
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Term
| The two types of electrical signals transmitted through neurons are __________. |
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Definition
| Graded and action potenials |
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Term
| The ion that plays a key role in initiating an action potential in a neuron is __________. |
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Definition
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Term
| __________ neurons from the afferent division of the PNS receive information from the body and transmit that information to an integrating center in the __________. |
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Definition
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Term
| The neurocrine that acts as the main inhibitory neurotransmitter in the brain is __________. |
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Definition
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Term
| Action potentials are unidirectional. Why do they travel only from the cell body of a neuron to the terminal and never go backward? |
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Definition
| The sodium channel inactivation gates close once an action potential passes. |
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Term
| The site of information integration in a neuron is the __________ |
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Definition
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