6494234
Descripción
Test por Med Student , actualizado hace más de 1 año
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Creado por Med Student
hace alrededor de 8 años
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Pregunta 1
Pregunta
The action potential of a nerve cell
Respuesta
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Results from a large increase in membrane permeability to Na+ ions
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Can summate with one another
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May vary considerably in amplitude
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Become larger as stimulus strength increase
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Follow from a decrease in membrane permeability for K+ ions
Pregunta 2
Pregunta
At neuromuscular junction:
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the muscle membrane possesses muscarinic receptors
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the motor nerve endings secrete norepinerphrine
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curare leads to prolongation of neuromuscular transmission
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the motor nerve endings secrete acetylcholine
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none of the above
Pregunta 3
Pregunta
The nervous system is compromised of:
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Neurons
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Neurotubules
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Neurofibrils
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Axons
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Dendrites
Pregunta 4
Pregunta
The unique property of the neuron is:
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Communication
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Contraction
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Secretion
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Energy production
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Excitation
Pregunta 5
Pregunta
Most axons are covered by a fatty sheath called:
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Neurilema
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The nodes of Ranvier
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Myelin
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Neural adipose
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Sacrolema
Pregunta 6
Pregunta
Receptors which respond in a stretch reflex are:
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Carotid baroreceptors
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Free nerve endings
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Ruffini's endings
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Oligodendrocytes
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Pacinan corpuscles
Pregunta 7
Pregunta
Select the excitatory neurotransmitter:
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GABA
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Dopamine
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Norepinerphrine
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Glycine
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None of them
Pregunta 8
Pregunta
Laws of transmission in chemical synapses
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One way conduction
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Amplitude coding of postsynaptic membrane
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Delayed transmission
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Summation
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All of the above
Pregunta 9
Pregunta
Which are the most important EEG waves during wakefulness with opened eyes
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Gamma (γ)
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Alpha (α)
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Beta (β)
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Delta (δ)
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Alpha (α) and Delta (δ)
Pregunta 10
Pregunta
The adrenergic receptors:
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Alpha
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Muscarinic
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Beta
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Nicotinic
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Alpha and Beta
Pregunta 11
Pregunta
Which one of the following is characteristic of type A nerve fibers:
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Nociception
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Slower conduction than C fibers
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Myelinated
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Substance P
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Sensory only
Pregunta 12
Pregunta
Electroencephalogram (EEG) registers the activity of the
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reticular activating system
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limbic system
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thalamus
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cortex
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brain stem
Pregunta 13
Pregunta
Sensory neurons have:
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a short dendrite and a long axon
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a short dendrite and a short axon
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a long dendrite and a short axon
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along dendrite and a long axon
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their axons and dendrites may be either long or short
Pregunta 14
Pregunta
The medulla oblongata helps regulate which of the following
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breathing
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heartbeat
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sneezing
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vomiting
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all of the above
Pregunta 15
Pregunta
What anatomical region of a multipolar neuron has the lowest threshold for generating an action potential?
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soma
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dendrites
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axon hillock
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distal axon
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proximal axon
Pregunta 16
Pregunta
What do the dorsal root ganglia contain?
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cell bodies of somatic motor neurons
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axon terminal of somatic motor neurons
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cell bodies of autonomic motor neurons
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axon terminal of sensory neurons
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cell bodies of sensory neurons
Pregunta 17
Pregunta
Prevertebral sympathetic ganglia are involved with the innervation of the
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abdominal organs
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thoracic organs
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head
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m. errector pili
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all of the above
Pregunta 18
Pregunta
A reflex action:
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is initiated at sensory receptors
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always results in endocrine secretion
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involves transmission across at least two central nervous synapses in series
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is always inhibitory
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is independent of higher centres in the brain
Pregunta 19
Pregunta
In skeletal muscle neuromuscular junctions:
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the motor end plate is the motor nerve terminal
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spontaneous (miniature) potentials may be recorded in the motor nerve terminal
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motor nerve terminals have vesicles containing acetylcholine
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there is a high concentration of curare
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transmission is facilitated by botulinum toxin
Pregunta 20
Pregunta
Cerebrospinal fluid:
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is formed in the arachnoid granulations
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provides the brain with most of its nutrition
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protects the brain from injury when the head is moved
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has a lower pressure than that in the cerebral venous sinuses
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flows around the adult brain and is around 5 litres per day
Pregunta 21
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An excitatory post-synaptic potential:
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is the depolarization of a post-synaptic nerve cell membrane that occurs when a presynaptic neurone is stimulated
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involves reversal of polarity across the post-synaptic nerve cell membrane
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may be recorded from a posterior root ganglion cell
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is propagated at the same rate as an action potential
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is caused by the electrical field induced by activity in the pre-synaptic nerve terminals
Pregunta 22
Pregunta
The ascending reticular formation:
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when stimulated tends to increase alertness
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transmits impulses to higher centres via a multisynaptic pathway
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is activated by collateral branches of sensory neurones
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neurones project to most parts of the cerebral cortex
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all of the above
Pregunta 23
Pregunta
The cerebellum:
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modifies the discharge of spinal motor neurones
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is essential for finely coordinated movements
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has an afferent input from the motor cortex
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has an afferent input from muscle proprioceptors
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all of the above
Pregunta 24
Pregunta
During deep sleep there is a fall in:
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hand skin temperature
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arterial pCO2
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blood growth hormone/cortisol ratio
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metabolic rate
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pH
Pregunta 25
Pregunta
Sympathetic:
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ganglionic transmission is mediated by acetylcholine
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neuromuscular transmission in the heart is mediated by acetylcholine
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neuromuscular transmission in hand skin arterioles is mediated by acetylcholine
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neuroglandular transmission in sweat! glands is mediated by noradrenaline
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neuromuscular transmission in the iris is mediated by acetylcholine
Pregunta 26
Pregunta
The blood-brain barrier:
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slows equilibration of solutes between blood and brain tissue
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is more effective barrier for fat-soluble substances than water-soluble substances
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is more effective barrier in infants than in adult
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is more effective barrier far CO2 than for 02
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permits hydrogen ions to pass freely
Pregunta 27
Pregunta
The electroencephalogram normally shows voltage waves:
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whose amplitude is related to intelligence
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of lower frequency during deep sleep than during alert wakefulness
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of smaller amplitude during deep sleep than during alert wakefulness
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of greater amplitude than those of the electrocardiogram
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which are bilaterally unsymmetrical
Pregunta 28
Pregunta
Parasympathetic nerves:
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have effects on intestinal smooth muscle opposite to sympathetic nerve
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have no effect on lacrimation
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cause vasodilatation in skeletal muscle during prolonged exercise
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cause sweat secretion in skin when body temperature rises
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have longer postganglionic than preganglionic fibres
Pregunta 29
Pregunta
α (alpha) adrenoceptors:
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are located on myofilaments in smooth muscle cells
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are distinguishable from β (beta) receptors using electron microscopy
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can be stimulated by both adrenaline and noradrenaline
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are involved in the vasodilation responses to adrenaline in skin
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are involved in heart rate responses to noradrenaline
Pregunta 30
Pregunta
The α (alpha) rhythm of the electroencephalogram:
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disappears when the eyes are closed
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is an electrical potential with an amplitude around one millivolt
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has a frequency of 8-12 Hz
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has a lower frequency than the δ (delta) rhythm
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indicates that the subject is sleeping
Pregunta 31
Pregunta
The primary sensory ending of a muscle spindle is stimulated by:
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shortening of an antagonist muscle
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relaxation of the muscle concerned when under load
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stimulation of the gamma efferent fibres
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striking the appropriate tendon with a tendon hammer
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all of the above
Pregunta 32
Pregunta
In the spinal cord:
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pain impulse traffic may be modulated in the posterior horn
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autonomic motor neurones arise in the lateral horn
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glycin acts as inhibitory neurotransmitter
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post-synaptic excitation may be mediated by amino acid derivatives acting as neurotransmitters
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all of the above
Pregunta 33
Pregunta
In the cerebral cortex
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neuronal connections are innate and immutable
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language and now-language skills are represented in the same hemisphere
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the areas concerned with emotional behavior are concentrated in the lobes
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the cortical area devoted to sensation in the hand is larger that for the trunk
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stimulation of the motor cortex causes contractions of individual muscles on the opposite side of the body
Pregunta 34
Pregunta
Generalized sympathetic activity is characterized by:
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contraction of the radial muscle in the iris
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increased urinary excretion of catecholamines
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lipolysis in adipose tissue
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increased conduction rate in the atrio-ventricular bundle
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all of the above
Pregunta 35
Pregunta
Acetylcholine:
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acts on the same type of receptor on postganglionic fibres in sympathetic and parasympathetic ganglia
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acts on the different type of receptor on target organs at cholinergic sympathetic and parasympathetic nerve terminals
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acts on the same type of receptor at autonomic ganglia and at somatic neuromuscular junctions
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acts on alpha and beta receptors
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in blood is hydrolyzed by the same cholinesterase as is found at neuromuscular junctions
Pregunta 36
Pregunta
An inhibitory post-synaptic potential:
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may be recorded in a post-ganglionic sympathetic neurone
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may be recorded in an axon
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does not exceed one millivolt in amplitude
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moves membrane potential towards the equilibrium potential for sodium
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may summate in space and time with other excitatory and inhibitory potentials in the same neurone
Pregunta 37
Pregunta
A valley of impulses travelling in a pro-synaptic neurone causes:
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an identical volley in the post-synaptic neurone
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summation of action potentials
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an increase in the permeability of the pare-synaptic nerve terminals to calcium
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the generation of at least one action potential in the post-synaptic neurone
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endocytosis of neurotransmitter
Pregunta 38
Pregunta
Pain receptors are:
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similar in structure to Pacinian corpuscles
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stimulated by a rise in the local K+ concentration
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quick to adapt to a constant stimulus
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more easily stimulated in intact than in injured tissue
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stimulated in the wall of the gut by agents which damage the tissues
Pregunta 39
Pregunta
Rapid eye movement (REM) sleep differs from non-REM sleep in that:
Respuesta
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the EEG shows waves of higher frequency
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muscle tone is higher
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heart rate and respiration are more regular
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secretion of growth hormone is increased
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not possible
Pregunta 40
Pregunta
Delta (δ) wave activity in the electroencephalogram:
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is low in frequency and amplitude
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suggests that the patient is alert and concentrating
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suggests that the patient is with opened eyes
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is a feature of petit mal epilepsy
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is more common in children than in adults while they are awake
Pregunta 41
Pregunta
Signs of brainstem death include:
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unconsciousness
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normal pupillary reaction to light
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loss of tendon jerks in the arms and legs
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loss of respiratory response to CO2 in the absence of hypoxia
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nystagmus in response to cold water in the external auditory canal
Pregunta 42
Pregunta
Atropine causes:
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paralysis of accommodation for near vision in the eye
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constriction of the pupil
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constriction of the bronchi
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diarrhea
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bradycardia
Pregunta 43
Pregunta
Aphasia:
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is an impairment of language skills without motor paralysis loss of hearing or vision
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does not mean unconsciousness
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is called motor aphasia if the patient understands what the speech sounds and symbols mean but lacks the higher motor skills needed to express them
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is called sensory aphasia if the patient does not understand the meaning of the words he hears, sees and uses
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all of the above
Pregunta 44
Pregunta
Blockade of parasympathetic activity causes a reduction in:
Respuesta
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sweat production
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resting heart rate
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the strength of skeletal muscle contraction
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salivation
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blood pressure
Pregunta 45
Pregunta
Blockade of beta (β) adrenoceptors is likely to cause:
Respuesta
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disturbance in renal-angiotensin-aldosterone system
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worsening of the condition in patients with bronchial asthma
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worsening of the condition in patients in cardiac failure
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inability to increase heart rate during exercise in patients with transplanted hearts
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all of the above
Pregunta 46
Pregunta
All of these characteristics belong to postsynaptic potentials, except for:
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they have constant magnitude
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there are no refractory periods
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summation is possible
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typically occur at the cell body of a neuron
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they are decremental
Pregunta 47
Pregunta
Compared with the Endocrine System, regulation of the body by the Nervous System provides:
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relatively slow but long-lasting responses to stimuli
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swift but brief responses to stimuli
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swift, long-lasting responses to stimuli
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antagonist hormone interactions
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relatively slow, short-lived responses to stimuli
Pregunta 48
Pregunta
Which of these characteristics is not related to the Parasympathetic division of the ANS?
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urination
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defecation
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salivation
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lacrimation
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posturation
Pregunta 49
Pregunta
Which of the following has slowest conduction:
Respuesta
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A alpha
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A beta
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A gamma
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B fibres
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C fibres
Pregunta 50
Pregunta
A man falls into deep sleep with one arm under his head. After awakening the arm is paralyzed but tingling sensation and pain sensation persist. This loss of motor function without the loss of sensory function is due to:
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A fibres are more susceptible to hypoxia that B fibers
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A fibres are more sensitive to pressure than C fibers
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C fibres are more sensitive to pressure than A fibers
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sensory nerves are nearer the bone and hence affected by pressure
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all of the above
Pregunta 51
Pregunta
Saltatory conduction:
Respuesta
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is seen only in myelinated nerve fibres
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is slower that non saltatory conduction
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is not affected if a local anesthetic is applied to the nodes of Ranvie
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is seen only in sensory fibers
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is seen only in the cortex
Pregunta 52
Pregunta
Myelin sheath is produced by:
Respuesta
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Axoplasm
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Mitochondria
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Schwann cell
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Muscle cell
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Endocrine cell
Pregunta 53
Pregunta
Sleep is associated with:
Respuesta
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an alpha rhythm in the electroencephalogram
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increased activity in the reticular activating system
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a beta rhythm in the EEG
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a high level of vagal tone to the heart and grinding movements of the teeth
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a rise in central body temperature
Pregunta 54
Pregunta
From childhood to old age:
Respuesta
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there is a steady decrease in total sleeping time per day
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deep (stage 4) Sleep decreases as a percentage of total daily sleep
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body water as a percentage of body mass decreases
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sleep becomes less aggregated into a single sleeping period
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all of the above
Pregunta 55
Pregunta
The method by which the brain's electrical activity is registered from the scalp is called:
Respuesta
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electroneurography (ENG)
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electroencephalography (EEG)
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electrocardiography (ECG)
-
electromyography (EMG)
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nuclear-magnetic resonance (NMR)
Pregunta 56
Pregunta
The sympathetic preganglionic neurons of the ANS secrete:
Respuesta
-
dopamine
-
L-DOPA
-
serotonin
-
histamine
-
acetylcholine
Pregunta 57
Pregunta
The adrenergic effect on the bronchial smooth muscle is:
Respuesta
-
constriction
-
relaxation
-
sometimes constriction, sometimes relaxation
-
of no effect
-
dose dependent - at low concentrations - constriction, at higher doses - relaxation
Pregunta 58
Pregunta
reflexes are defined as somatic, visceral and mixed
Respuesta
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according to the location of the receptors
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according to the type of the reflex arc
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according to the effectors
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according to the location of the interneurons
-
according to formation
Pregunta 59
Pregunta
The adrenal medulla is innervated by:
Respuesta
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preganglionic cholinergic neurons
-
postganglionic cholinergic neurons
-
preganglionic adrenergic neurons
-
postganglionic adrenergic neurons
-
preganglionic dopaminergic neurons
Pregunta 60
Pregunta
The increased tone of the parasympathetic division leads to:
Respuesta
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contraction of the pupils and bronchial smooth muscle fibers
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dilation of the pupils and relaxation of the bronchial smooth muscle fibers
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contraction of the pupils and relaxation of the bronchial smooth muscle fibers
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dilation of the pupils and contraction of the bronchial smooth muscle fibers
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none of the above
Pregunta 61
Pregunta
Excessive formation of a substance/ secretion in the body is controlled in order to maintain homeostasis by:
Respuesta
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+ve feedback mechanism
-
-ve feedback mechanism
-
osmosis
-
haemodynamics
-
Up-regulation
Pregunta 62
Pregunta
The sympathetic response to stress includes:
Respuesta
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increased blood pressure
-
increased glycogen breakdown in liver and muscles
-
increased glycogen synthesis in liver and muscles
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increased blood clotting
-
a, b, and d
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