Practice Questions Flashcards
Which of the following statements is TRUE regarding the stretch reflex?
A)
It involves afferent activity from muscle spindles whose axons travel up the spinal cord in the anterolateral columns.
B)
It reduces the force the ipsilateral muscles produce during contraction.
C)
It resists changes in muscle length.
D)
Relative to the muscle spindles being stretched, it involves excitation of contralateral motor neurons.
E)
None of the statements are true.
C
What is NOT true about the auditory system?
A)
Tip links located at the base of the stereocilia open mechanically-gated ion channels.
B)
Before speaking, skeletal muscles in your middle ear contract to stop you from damaging your own auditory system.
C)
You can damage your hearing listening to music at amplitudes that do not produce pain.
D)
Sounds at 4,000 Hz can be detected at smaller amplitudes compared to sounds at 400 Hz.
E)
The shape of the pinna reflects pressure waves into the auditory canal.
A
Which of the following statements is TRUE?
A)
None of the statements are true.
B)
The basal nuclei are part of the highest level of brain’s motor control system.
C)
Lesioning descending motor pathways leads to decreased muscle tone and reflexes.
D)
The cerebellum receives and integrates sensory information for motor learning.
E)
Voluntary movements are consciously initiated in the primary motor cortex.
D
Which of the following statements is TRUE?
A)
Alpha motor neurons innervate intrafusal muscle fibers.
B)
Gamma motor neurons innervate Golgi tendon organs.
C)
Ia primary afferents adapt.
D)
None of the statements are true.
E)
Muscle spindles are connected in series with extrafusal muscle fibers.
C
Which of the following is FALSE regarding the corticospinal motor pathway?
A)
It is responsible for the control of highly skilled voluntary movements.
B)
It can directly activate motor neurons.
C)
It originates from the postcentral gyrus.
D)
It mainly controls the hands and feet.
E)
It crosses the midline in the medulla.
C
Which of the following disease–symptom pairs is NOT observed?
A)
Parkinson’s disease and bradykinesia.
B)
Motor neuron damage and hypotonia.
C)
Huntington’s disease and hyperkinesia.
D)
Cerebellar degeneration and paralysis.
E)
Huntington’s disease and choreiform movements.
D
In the withdrawal reflex, limb withdrawal persists even after removal of the painful stimulus because of
A)
activation of the motor cortex.
B)
muscle spindle over-activity.
C)
irradiation
D)
feedback loops in the spinal cord.
E)
recruitment of interneurons.
D
During COVID19 you are locked down in a very small apartment with a roommate who eats only beans. Which is true regarding the orderant molecules produced by your roommate’s unending flatulence?
A) Tip links located at the base of the stereocilia open mechanically-gated ion channels.
B)
They eventually trigger an emotional response via activation of the olfactory track that projects directly to your limbic system.
C)
They bind to only one of your 10,000 specialized oderant receptors.
D)
They directly flow though specialized ion channels located in the cilia of receptor cells.
E)
They bind to receptor cells located in the olfactory bulb.
B
Which of the following statements about sleep is TRUE?
A)
Stage 4 sleep has lower amplitude waves than Stage 1 on EEG
B)
None of the statements are true.
C)
Dreaming occurs primarily during Stage 3 sleep
D)
Sleep apnea is a sudden increase in respiration during REM sleep
E)
REM sleep is also called “paradoxical sleep” because of its similarity to the waking state on EEG
E
The mesolimbic pathway
A)
involves the hippocampus.
B)
is responsible for emotional responses.
C)
uses mainly serotonergic neurotransmission.
D)
projects to the frontal lobes and controls motivation.
E)
activates the suprachiasmatic nucleus.
D
Red blood cells…
A)
are derived from large stem cells, known as megakaryocytes.
B)
lack mitochondria, but contain enzymes allowing them to generate some ATP anaerobically.
C)
are characterized by a large volume - to - surface area ratio.
D)
in the adult, are produced in the marrow of all the bones.
E)
play an essential role in blood clot formation.
B
Platelets…
A)
have a normal lifespan of 7-10 weeks.
B)
lack all subcellular organelles.
C)
are produced in the liver during the postnatal period.
D)
develop from immature cells known as reticulocytes.
E)
play an essential role in both primary and secondary hemostasis.
E
Edema may develop in all the following situations EXCEPT (choose the INCORRECT one):
A)
Elevated blood pressure.
B)
Elevated capillary permeability.
C)
Elevated plasma osmolarity.
D)
Obstructed lymphatic drainage.
E)
Lowered plasma colloidal osmotic (oncotic) pressure.
C
Which statement regarding the various plasma proteins is CORRECT?
A)
They are responsible for generating a plasma osmotic pressure of 6.7 atmospheres (5100 mm Hg).
B)
γ-globulin has the largest molecular weight, but has the fastest electrophoretic mobility.
C)
In the adult, all of the plasma proteins are synthesized in the liver.
D)
Albumin has the smallest molecular weight, but is present in the largest concentration.
E)
Fibrinogen is present in a larger concentration in serum than in plasma.
D
Which statement about iron is CORRECT?
A)
Each hemoglobin molecule contains one iron atom, which is capable of reversibly binding one molecule of oxygen.
B)
The absorption of iron from the gastrointestinal tract, requires the presence of Intrinsic Factor secreted by the stomach.
C)
Iron is transported in plasma bound to a protein named Ferritin.
D)
Of the 25 mg of iron released daily from the destruction of red blood cells in the body, only 1mg is recycled, and the rest is excreted.
E)
Dietary Iron requirements are normally lower for healthy young adult males, than for healthy young women of child-bearing age.
E
Bilirubin…
A)
is an iron-rich molecule.
B)
is derived from the degradation of the globin portion of the hemoglobin molecule.
C)
is largely recycled in the body, with its constituents being reutilized in erythropoiesis.
D)
is responsible for the normal colour of plasma
E)
is absent from serum.
D
All of the following statements about the intrinsic scheme of coagulation are CORRECT EXCEPT (choose the INCORRECT statement):
A)
It does not require the presence of Ca++.
B)
It involves protein factors which are produced by the liver.
C)
It may be accelerated by the presence of Thrombin.
D)
It may be triggered by damage to the vascular endothelial lining.
E)
It requires more time for its development than does the extrinsic scheme.
A
All of the following statements regarding the Hematocrit are TRUE, EXCEPT (choose the FALSE statement):
A)
The hematocrit is normally higher in males than in females.
B)
The hematocrit is likely to be higher in patients suffering from generalized edema.
C)
The hematocrit is expressed as a percentage.
D)
The hematocrit Is higher in individuals living at high altitudes than in those living at sea level.
E)
A high hematocrit is always indicative of polycythemia.
E
Erythropoietin…
A)
is released into the circulation in response to hypoxia.
B)
acts on the multipotential hematopoietic stem cell, inducing it to give rise to red blood cell precursors.
C)
All of the statements are CORRECT.
D)
acts on circulating red blood cells, causing the extension of their lifespan.
E)
is produced mainly by the liver.
A
The Starling Forces…
A)
are primarily responsible for the efficient exchange of nutrients, gases, and wastes across the capillary wall.
B)
include the process of filtration which tends to “pull in” or retain fluid inside the capillaries.
C)
are responsible for the relative distribution of fluid volume between the ICF and the ECF compartments.
D)
play an important role in determining the total osmolarity of plasma.
E)
maintain the distribution of the ECF volume between the ISF and the plasma in the normal ratio of 3:1.
E
Which of the following is the best metaphor for the function of neuronal dendrites?
A)
The dendrites are like the pump on an aquarium.
B)
The dendrites are like the undersea telephone cables that connect North America and Europe.
C)
The dendrites are like sprawling antennae, receiving information from a large number of external sources.
D)
The dendrites are like the facilities that provide heat, water and electricity to the McGill campus.
E)
The dendrites are like a flashlight battery.
C
Which of the following is an important functional difference between NMDA receptors and AMPA receptors?
A)
AMPA receptors are found in the vertebrate nervous system, whereas NMDA receptors are only found in the invertebrate nervous system.
B)
NMDA receptors are blocked by magnesium at the resting membrane potential, whereas AMPA receptors are not.
C)
NMDA receptors are permeable to sodium ions, whereas AMPA receptors are not.
D)
NMDA receptors are found in the central nervous system, whereas AMPA receptors are found only in the peripheral nervous system.
E)
Activation of NMDA receptors requires simultaneous binding of both glutamate and GABA.
B
Which of the following experimental manipulations would cause release of neurotransmitter from the neuronal presynaptic terminal?
A)
Injecting calcium into the presynaptic terminal.
B)
Blocking voltage-gated sodium channels with tetrodotoxin.
C)
Injecting Botox into the presynaptic terminal.
D)
Hyperpolarizing the presynaptic terminal.
E)
Removing calcium from the extracellular solution.
A
How is information relayed from one part of the nervous system to another?
A)
By length of action potentials
B)
By the speed that action potentials move down axons
C)
By the frequency and pattern of action potentials
D)
By the force of action potentials
E)
By the size of action potentials
C
Which of the following is the best description of the role of dendrites in the function of neurons and the nervous system?
A)
Dendrites receive and integrate signals from other neurons.
B)
Dendrites are the principle sites of protein synthesis and metabolism in the neuron.
C)
Dendrites release neurotransmitters.
D)
Dendrites propagate signals from one part of the nervous system to another.
E)
Dendrites store synaptic vesicles.
A
Pentobarbital enhances the response of GABA receptors to GABA. Which effect would most likely be associated with this drug?
A)
Excessive nervousness.
B)
Hyperexcitability and seizures.
C)
Cardiac arrest.
D)
Sedation (sleepiness).
E)
Muscle paralysis.
D
Which of the following is the best definition of the resting membrane potential?
A)
It is the potential for neurons to fire action potentials.
B)
It is the potential of the neuron to remain at rest if it does not receive any excitatory synaptic inputs.
C)
It is the potential for the neuron membrane to have ion channels.
D)
It is the potential energy gradient across the external membrane of the neuron.
E)
It is the potential difference in the concentration of sodium ions between the inside and outside of the neuron.
D
Which of the following is the best description of the active zone?
A)
It is the region of the presynaptic terminal at which the synaptic vesicles fuse and neurotransmitter is released.
B)
It is the region of the postsynaptic membrane which contains the neurotransmitter receptors.
C)
It is the area of the neuron engaged in active protein synthesis.
D)
It is the region of the axon where the action potential is initiated.
E)
It is the region of dendrite with the highest number of excitatory synapses.
A`
Imagine you are a neuroscientist, and you have just created a strain of “knockout” mutant mice that do not make the voltage-gated potassium channels normally found in axons. Voltage-gated sodium channels and potassium leak channels are still expressed normally in the axon membrane. Which of the following properties would you expect the mutant mice to have?
A) The falling (repolarizing) phase of the action potential in mutants will be faster than in normal control mice.
B) The falling (repolarizing) phase of the action potential in mutants will be slower than in control mice.
C)
Action potentials in the mutant mice will be indistinguishable from control mice.
D)
The relative refractory period between action potentials will be longer in mutant mice than in control mice.
E)
The axons of the mutant mice will not propagate action potentials.
B
Injection of myelin basic protein into animals causes an immune response which results in destruction of myelin in the central nervous system.This experimental disease has been used as a model for which of the following nervous system disorders?
A)
Alzheimer’s disease
B)
Parkinson’s disease
C)
Schizophrenia
D)
Drug addiction
E)
Multiple sclerosis
E
Which statement about the difference between insensible perspiration and sweating is TRUE?
A)
Insensible perspiration is possible in people without sweat glands, unlike sweating.
B)
Insensible perspiration is halted in cool environments, but sweating is continuous.
C)
Insensible perspiration contains more electrolytes than sweat.
D)
Insensible perspiration is a facultative loss, while sweating is obligatory.
E)
Insensible perspiration can be voluntarily controlled, unlike sweating.
A
What type of cellular transport involves the cytosolic protein clathrin?
A) Secondary active transport
B) Receptor-mediated endocytosis
C) Primary active transport
D) Pinocytosis
E) Exocytosis
B
Which of the following is TRUE?
A) The differences in body water between individuals become significant when body water content is calculated as a fraction of lean body mass.
B) Sweating is type of facultative loss.
C) Excessive water intake can cause a negative water balance.
D) A 30-year old woman has a lower percentage of body water than a 10-year old boy.
E) Bone contains less water than does adipose tissue.
D
A solute, X, is placed in compartment A of a two-compartment container and allowed to diffuse to compartment B and attain diffusion equilibrium. At that point in time…
A) solutes will continue to move from A to B only.
B) solutes will continue to move from B to A only.
C) there will be no further movement of solute molecules between compartments.
D) solutes will be moving in both directions equally.
E) the concentration in compartment B will be much higher than that in compartment A.
D
Which is TRUE about mediated transport across cell membranes? Mediated transport…
A)is nonspecific, in that, any transporter can transport any molecule.
B) rate always increases as concentration across the membrane increases.
C) refers to simple diffusion.
D) refers to the movement of ions through channels.
E) is characterized by saturable carriers and a maximum transport velocity.
E
If a cell has an osmolarity of 300 mOsm, which of the following is a hypotonic solution?
A) NONE B) 0.10 M glucose C) 0.30 M sucrose D) 0.10 M CaCl2 E) 0.20M NaCl
B