PHSL2101 Finals

Pregunta 1 de 84

1

Golgi tendon organs:

Selecciona una de las siguientes respuestas posibles:

respond primarily to muscle length.
cause monosynaptic excitation of alpha motoneurons.
are rapidly adapting receptors.
are in series with extrafusal muscle fibres.
are in parallel with intrafusal muscle fibres.

Explicación

Pregunta 2 de 84

1

Reflexes

Selecciona una de las siguientes respuestas posibles:

must take less than 10ms otherwise they are not involuntary
require only an integrator and an effector.
can be used to keep a limb in position.
must involve a proprioceptive afferent such as a Golgi tendon afferent.
are not signalled to the cortex.

Explicación

Pregunta 3 de 84

1

The traces below show action potential recordings from nine different peripheral afferent fibres. Which ONE of the following physical stimuli is most likely to have caused the observed pattern of activity?

Selecciona una de las siguientes respuestas posibles:

The blunt end of a pencil pressed firmly against the skin.
The sharp edge of a knife pressed firmly against the skin.
An ice cube pressed gently against the skin.
A flat piece of plastic pressed gently against the skin.
A candle flame held near the skin.

Explicación

Pregunta 4 de 84

1

Choose the CORRECT statement. The vestibular system:

Selecciona una de las siguientes respuestas posibles:

provides reflex information that does not go to the cortex.
uses hair cells to convert an electrical potential to mechanical energy.
uses the semicircular canals to detect linear acceleration.
would not generate any useful signals in a zero-gravity environment.
uses the utricle and saccule to provide information about static head position.

Explicación

Pregunta 5 de 84

1

Which ONE of the following statements is CORRECT with regard to the
organisation of the spinal cord and peripheral nervous system?

Selecciona una de las siguientes respuestas posibles:

Dorsal root ganglia contain the soma of sensory neurons.
A dermatome is innervated from multiple levels of spinal nerves.
Ventral roots contain mainly afferent fibres.
The spinal cord has a core of white matter surrounded by grey matter.
Efferent fibres take information from the periphery to the central nervous system.

Explicación

Pregunta 6 de 84

1

Shown in A and B are the action potentials generated in a single tactile afferent over 1s, under two different conditions. The alteration in response from A to B is due to a change in the applied stimulus. The stimulus change that best accounts for the response change from A to B is:

Selecciona una de las siguientes respuestas posibles:

making the stimulus surface contact the skin with less force.
increasing the temperature of the stimulus surface that contacts the skin.
making the stimulus surface contact the skin for less time.
moving the stimulus surface more quickly across the skin.
making the stimulus surface contact the skin over a larger area.

Explicación

Pregunta 7 de 84

1

Inhibitory synapses from a GABA-ergic neuron:

Selecciona una de las siguientes respuestas posibles:

play an important role in synaptic transmission at the vertebrate neuromuscular junction.
can prevent the postsynaptic neuron from reaching threshold.
depolarise the post-synaptic neuron membrane potential towards 0 mV.
cause IPSPs that do not interact with EPSPs in the same post-synaptic neuron.
are not found on neurons that also receive excitatory input.

Explicación

Pregunta 8 de 84

1

Which ONE of the following statements about optical defects is CORRECT?

Selecciona una de las siguientes respuestas posibles:

The prevalence of myopia is higher in the over 40 population.
Presbyopia is also called shortsightedness.
Myopia is corrected with a convex lens.
Hyperopia is usually not corrected in adolescent patients.
Presbyopia is corrected with a concave lens.

Explicación

Pregunta 9 de 84

1

Choose the best option from the following table about spindle and Golgi tendon
organ afferents.

Selecciona una de las siguientes respuestas posibles:

A
B
C
D
E

Explicación

Pregunta 10 de 84

1

Which ONE of the following statements about motor pathways is CORRECT?

Selecciona una de las siguientes respuestas posibles:

The extrapyramidal tracts synapse onto spinal motor neurons.
The extrapyramidal tracts are predominantly involved in control of limb muscles.
The corticospinal tract originates mainly in the basal ganglia.
The corticospinal tract carries afferent information.
The corticospinal tract crosses the midline.

Explicación

Pregunta 11 de 84

1

Three neurons (designated N1, N2 and N3) synapse onto a common post-synaptic neuron. Simultaneous synaptic activity in these neurons has the following effects:
N1 and N2: post-synaptic action potential
N2: postsynaptic
action potential
N2 and N3: no post-synaptic action potential

Which of the following is the most likely conclusion?

Selecciona una de las siguientes respuestas posibles:

N1 is inhibitory, N2 is subthreshold excitatory, N3 is subthreshold excitatory.
N1 is suprathreshold excitatory, N2 is subthreshold excitatory, N3 is inhibitory.
N1 is subthreshold excitatory, N2 is suprathreshold excitatory, N3 is inhibitory.
N1 is subthreshold excitatory, N2 is subthreshold excitatory, N3 is inhibitory.
N1 is inhibitory, N2 is suprathreshold excitatory, N3 is subthreshold excitatory.

Explicación

Pregunta 12 de 84

1

Which ONE of the following statements about cerebrospinal fluid is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

It fills axons and the central canal of the spinal cord.
It freely exchanges with the brain interstitial fluid.
It is produced from blood at the choroid plexus.
It provides an appropriate chemical environment for the brain.
It enables the brain to float inside the skull.

Explicación

Pregunta 13 de 84

1

Which ONE of the following statements is CORRECT with regard to sensory receptors and afferents? Sensory receptors and afferents characterised as “rapidly adapting” or “phasic”:

Selecciona una de las siguientes respuestas posibles:

can encode only the intensity of a stimulus.
only generate action potentials when the stimulus changes location.
generate action potentials continuously during a steady stimulus.
generate more action potentials during changes in stimulus intensity than during steady stimulation.
include the type of receptor used to encode joint angle.

Explicación

Pregunta 14 de 84

1

A person with normal vision except for anomalous trichromacy (red-green colourblindness):

Selecciona una de las siguientes respuestas posibles:

sees yellow as blue.
has blurry vision.
sees blue as grey.
sees red and green as grey.
sees purple as grey.

Explicación

Pregunta 15 de 84

1

In transducing mechanical energy into a neural signal, the cochlear hair cells:

Selecciona una de las siguientes respuestas posibles:

utilise ligand-gated channels near the apical border of the cell.
receive a chemical signal from the tectorial membrane.
utilise an influx of cations to depolarise the hair cell.
have the same response to a forwards deflection of the stereocilia as to a backwards deflection.
employ stereocilia that allow a single hair cell to combine the sound signals from the two ears.

Explicación

Pregunta 16 de 84

1

During normal voluntary muscle contraction (alpha and gamma co-activation):

Selecciona una de las siguientes respuestas posibles:

extrafusal fibres provide most of the contractile force.
intrafusal muscle fibres shorten while extrafusal fibres do not.
gamma motor neurons activate the alpha motor neurons.
extrafusal muscle fibres shorten while intrafusal fibres do not.
contraction of the intrafusal muscle fibres weakens the stretch reflex.

Explicación

Pregunta 17 de 84

1

Which ONE of the following statements about cerebrospinal fluid (CSF) is CORRECT?

Selecciona una de las siguientes respuestas posibles:

CSF is made at the choroid plexus.
CSF contains the same white blood cell count as blood, but no red blood cells.
CSF is found both inside and outside the meninges.
CSF has a higher K+ concentration than Na+ concentration.
The volume of CSF in a normal individual is approximately the same as the volume of plasma.

Explicación

Pregunta 18 de 84

1

With regard to the organisation of somatosensory cortex:

Selecciona una de las siguientes respuestas posibles:

The cortical representation of temperature sense in the right hand is located in the opposite hemisphere to the cortical representation of touch in the right hand.
The cortical representation of the hand is found near that of the face.
The cortical representation of the hip lies between the representations of the foot and knee.
The cortical area allocated to touch for the wrist is larger than that allocated to touch for the thumb.
The cortical representation of touch for the right hand is found in the right somatosensory cortex.

Explicación

Pregunta 19 de 84

1

Which ONE of the following statements about the photoreceptors of the retina is CORRECT?

Selecciona una de las siguientes respuestas posibles:

Both rods and cones are found in the centre of the visual field.
There are three types of rod photoreceptors and one type of cone photoreceptor.
There are more cones than rods in the retina.
In the peripheral retina, rods are more common than cones.
The highest density of photoreceptors in the eye is at the optic disc.

Explicación

Pregunta 20 de 84

1

With regard to spinal motor neurons:

Selecciona una de las siguientes respuestas posibles:

A motor unit may be composed of more than one alpha motor neuron.
A motor unit is composed of an alpha motor neuron and a single muscle fibre.
A single action potential in a single alpha motor neuron does not cause muscle contraction.
The activity of an alpha motor neuron can be influenced by descending cortical input.
Alpha motor neurons synapse onto spindle afferent neurons.

Explicación

Pregunta 21 de 84

1

The traces below show action potential recordings from nine different peripheral afferent fibres. What was the likely movement of the stimulus relative to the finger?

Selecciona una de las siguientes respuestas posibles:

The stimulus was moved across the tip of the finger.
The stimulus was moved along the finger from tip to base.
No movement.
The stimulus was moved along the finger from base to tip.
The stimulus was touched on the finger three times, first at the base, then at the middle and finally at the tip of the finger.

Explicación

Pregunta 22 de 84

1

The blood-brain barrier:

Selecciona una de las siguientes respuestas posibles:

is produced by astrocytes and endothelial cells of the capillary wall.
prevents all drugs from reaching the brain.
is permeable to both red blood cells and white blood cells.
is a semipermeable membrane that encases the brain and cerebrospinal fluid.
is permeable to most small polar molecules.

Explicación

Pregunta 23 de 84

1

Tactile sensory fibres with large receptive fields:

Selecciona una de las siguientes respuestas posibles:

do not have topographically-organised projections.
innervate body regions with low receptor densities.
have a large area of cortex dedicated to processing their input.
permit precise localization of the site of a tactile stimulus.
are found in body regions with small two- point discrimination thresholds.

Explicación

Pregunta 24 de 84

1

With regard to image formation by the eye:

Selecciona una de las siguientes respuestas posibles:

the focal point of the eye lies between the cornea and the lens.
myopia is a condition in which the image of a distant object is formed behind the retina.
the retinal image is an upright image of the object.
the cornea has greater optical power than the lens.
the cornea and lens are concave lenses.

Explicación

Pregunta 25 de 84

1

Choose the CORRECT statement about the retina.

Selecciona una de las siguientes respuestas posibles:

Increased light intensity causes increased transmitter release from photoreceptors.
Stimulus colour is coded by the activity of rod photoreceptors.
Rod photoreceptor
Rod photoreceptors outnumber cone photoreceptors throughout the retina except at the fovea.
Stimulus location is coded by the type of photoreceptor activated.

Explicación

Pregunta 26 de 84

1

Which ONE of the following statements about the structure of the brain is CORRECT?

Selecciona una de las siguientes respuestas posibles:

The ventricles are formed by axons
The corpus callosum is a grey matter structure.
Connections between cortical areas are made by white matter tracts.
The grey matter of spinal cord is organised as a thin sheet of neurons.
The layers of cortex run perpendicular to the cortical surface.

Explicación

Pregunta 27 de 84

1

Choose the option that correctly assigns the roles of the outer, middle and inner ear.

Selecciona una de las siguientes respuestas posibles:

outer ear: sound transduction,
iddle ear: impedance matching,
inner ear: modify sound based on location of source transduction.
outer ear: impedance matching,
middle ear: sound transduction,
inner ear: modify sound based on location of source.
outer ear: modify sound based on location of source,
middle ear: impedance matching,
inner ear: sound transduction.
outer ear: modify sound based on location of source,
middle ear: sound transduction,
inner ear: impedance matching.
outer ear: impedance matching,
middle ear: modify sound based on location of source,
inner ear: sound transduction.

Explicación

Pregunta 28 de 84

1

Which of the following sensory parameters are topographically organised in their primary sensory cortex?

Selecciona una de las siguientes respuestas posibles:

A
B
C
D
E

Explicación

Pregunta 29 de 84

1

In the myotatic reflex:

Selecciona una de las siguientes respuestas posibles:

the 1A afferents increase their firing rate in response to increased muscle tension.
the extrafusal muscle fibres relax due to 1A activity.
the 1B afferents increase their firing rate in response to increased muscle length.
the intrafusal muscle fibres contract due to 1B activity.
the extrafusal muscle fibres contract due to 1A activity.

Explicación

Pregunta 30 de 84

1

Which ONE of the following statements about the spinal cord is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

A dermatome refers to the region of skin innervated by a single spinal nerve.
The spinal nerves have an organization where the sacral nerves tend to innervate the face, and the cervical nerves innervate the legs.
The ventral horn of the spinal cord contains motor neurons.
The spinal nerves may fuse and join on their way to innervate their target zone.
The spinal nerves are formed from the fusion of the dorsal and ventral root.

Explicación

Pregunta 31 de 84

1

A person who is unable to see things to the left side of where their gaze is directed has probably suffered damage to:

Selecciona una de las siguientes respuestas posibles:

their left visual thalamus (lateral geniculate nucleus).
their right visual cortex (occipital lobe).
their left optic nerve after the optic chiasm.
their left eye.
their right optic nerve before the optic chiasm.

Explicación

Pregunta 32 de 84

1

With regard to the vestibular senses:

Selecciona una de las siguientes respuestas posibles:

The semicircular canals use small rocks to help detect inertia.
The semicircular canals can signal linear acceleration without significant adaptation.
The otolith organs can signal linear acceleration without significant adaptation.
The semicircular canals can signal the direction of gravitational acceleration.
The otolith organs can signal the direction of a steady velocity.

Explicación

Pregunta 33 de 84

1

When preparing to reach down and pick up a bag, which brain area would be the final motor area to be activated before the movement begins?

Selecciona una de las siguientes respuestas posibles:

cerebellum
supplementary motor area
primary motor cortex
pre-motor area
basal ganglia

Explicación

Pregunta 34 de 84

1

The pitch of a pure tone:

Selecciona una de las siguientes respuestas posibles:

is determined by the amplitude of the sound wave
is not one of the properties coded for in auditory cortex.
determines where the travelling wave in the basilar membrane has its peak.
is coded by the rate of firing of cochlear afferent fibres.
would be dramatically affected by a blockage in the middle ear due to infection.

Explicación

Pregunta 35 de 84

1

When a neuron adapts to a stimulus, this means that it:

Selecciona una de las siguientes respuestas posibles:

becomes more selective for the properties of that stimulus.
generates stronger action potentials.
becomes sensitised to the stimulus.
changes its morphology to accommodate the stimulus.
generates action potentials at a lower rate.

Explicación

Pregunta 36 de 84

1

Which ONE of the following statements about the functional organization of the brain is CORRECT?

Selecciona una de las siguientes respuestas posibles:

The limbic system is a group of brain areas primarily related to motor control.
There is a specialised region of cortex for vision at the front of the brain.
The left cortical hemisphere generally controls the right side of the body.
Sensory systems are usually restricted to one level of the brain e.g. brain stem
The thalamus is a single nucleus with inputs from sensory and motor areas.

Explicación

Pregunta 37 de 84

1

Which ONE of the following statements is CORRECT with regard to the skin pain system?

Selecciona una de las siguientes respuestas posibles:

Strong activation of tactile afferents will cause a sensation of pain.
The ipsilateral (same side) cortical hemisphere processes nociceptive inputs.
Nociceptive afferent fibres are slower to relay a signal to the spinal cord than the afferents for light touch on the fingers.
A person with their spinal cord severed at chest level would have paralysed legs but would still feel painful stimuli applied to their feet.
Nociceptive afferents synapse directly on alpha motor neurons to mediate the withdrawal reflex.

Explicación

Pregunta 38 de 84

1

The volume reflex, in which heart rate and renal blood flow are increased following an increase in blood volume, is mediated primarily by:

Selecciona una de las siguientes respuestas posibles:

atrial and vena cava baroreceptors
aortic baroreceptors
a combination of atrial and vena cava baroreceptors, aortic baroreceptors and carotid sinus baroreceptors
carotid sinus baroreceptors
peripheral chemoreceptors

Explicación

Pregunta 39 de 84

1

The function of the papillary muscles and chordae tendinae is to:

Selecciona una de las siguientes respuestas posibles:

Keep the AV valves from bulging into the atria during ventricular contraction.
Keep the AV valves from bulging into the aorta and pulmonary arteries during systole.
Hold the AV valves open during diastole.
Increase backflow into the ventricles during diastole.
Hold open the semilunar valves during systole.

Explicación

Pregunta 40 de 84

1

During which phase of the cardiac cycle are all four heart valves open?

Selecciona una de las siguientes respuestas posibles:

isovolumetric ventricular contraction
atrial systole
rapid and reduced filling
ventricular ejection
all four heart valves are normally never open simultaneously

Explicación

Pregunta 41 de 84

1

If systemic blood pressure falls, the carotid baroreceptors would cause heart rate to and peripheral __.

Selecciona una de las siguientes respuestas posibles:

Decrease, vasoconstriction
Decrease, vasodilation
Stay the same, vasoconstriction
Increase, vasodilation
Increase, vasoconstriction

Explicación

Pregunta 42 de 84

1

The firing rate of aortic baroreceptors is increased by

Selecciona una de las siguientes respuestas posibles:

increased blood oxygen concentration.
activation of receptors in the right atrium.
increased blood pressure.
decreased blood pressure.
decreased blood oxygen concentration.

Explicación

Pregunta 43 de 84

1

The major mechanism controlling the diameter of arteries in the skin is:

Selecciona una de las siguientes respuestas posibles:

accumulation of metabolic waste products
sympathetic nerve activity
extracellular K+ concentration
myogenic
extracellular CO concentration

Explicación

Pregunta 44 de 84

1

Which ONE of the following would NOT result in an increase in the movement of fluid out of capillaries?

Selecciona una de las siguientes respuestas posibles:

An increase in blood pressure within the capillary.
A decrease in colloid osmotic pressure of the plasma.
None of the above.
A decrease in interstitial fluid pressure.
A decrease in the osmotic pressure of the interstitial fluid.

Explicación

Pregunta 45 de 84

1

According to the Starling Equation, which ONE of the following would NOT be a factor in the net filtration pressure controlling the movement of water across the capillary wall?

Selecciona una de las siguientes respuestas posibles:

Hydrostatic (blood) pressure in the capillary.
The interstitial fluid pressure.
The number and size of the pores in the capillary wall.
The plasma protein concentration.
The concentration of Na in the interstitial fluid.

Explicación

Pregunta 46 de 84

1

Which ONE of the following parameters, when increased, will cause an increase
in cardiac stroke volume?

Selecciona una de las siguientes respuestas posibles:

afterload
end-diastolic volume (EDV)
end-systolic volume (ESV)
peripheral resistance
blood pressure

Explicación

Pregunta 47 de 84

1

Unlike blood vessels, the lymphatic system:

Selecciona una de las siguientes respuestas posibles:

reabsorbs protein and foreign particles from the interstitial fluid.
removes damaged erythrocytes from the circulation.
has a role in controlling blood pressure.
forms a filtrate which eventually becomes urine.
can generate local vasoactive substances.

Explicación

Pregunta 48 de 84

1

The major mechanism controlling coronary artery diameter is:

Selecciona una de las siguientes respuestas posibles:

accumulation of metabolic waste products.
sympathetic nerve activity.
extracellular CO concentration.
extracellular K concentration.
venular constriction.

Explicación

Pregunta 49 de 84

1

Blood that leaves the right ventricle and later enters the left ventricle must have passed through which of the following valves?

Selecciona una de las siguientes respuestas posibles:

Pulmonary and bicuspid/mitral valves.
Pulmonary valve only.
Bicuspid/Mitral and aortic valve
Aortic and Tricuspid valves.
Bicuspid/mitral valve only.

Explicación

Pregunta 50 de 84

1

Which ONE of the following statements regarding blood vessels is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

Capillaries are the vessel type that have the greatest total surface area.
The pressure in venules would be less than the pressure in large veins.
The elastic nature of the walls of arteries allows them to act as a pressure
reservoir.
Veins function as volume reservoirs due to their high compliance
The contractile activity of smooth muscle cells within arterioles is primarily involved in the control of organ blood flow.

Explicación

Pregunta 51 de 84

1

According to Fick’s law, which ONE of the following would NOT be a factor in diffusion of a substance across the capillary wall?

Selecciona una de las siguientes respuestas posibles:

The molecular weight of the substance
The concentration of the substance in the interstitial fluid
The total surface area of the capillary wall
Hydrostatic (blood) pressure in the capillary
The plasma concentration of the substance

Explicación

Pregunta 52 de 84

1

The decrease in blood pressure is greatest across because this is where is highest.

Selecciona una de las siguientes respuestas posibles:

capillaries, resistance
arterioles, resistance
capillaries, cross-sectional area
veins, cross-sectional area
aorta, cross-sectional area

Explicación

Pregunta 53 de 84

1

A reflex increase in heart rate may be caused by:

Selecciona una de las siguientes respuestas posibles:

an increase in right atrial pressure.
an increase in venous return.
a decrease in arterial blood pressure.
a decrease in peripheral resistance.
all of the above.

Explicación

Pregunta 54 de 84

1

Which ONE of the following statements about an action potential generated from a non-pacemaker cardiac cell is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

The plateau phase of the action potential is associated with a prolonged increase in Ca2+ permeability.
The resting membrane potential depends to a great extent on the permeability of the cell membrane to K+.
Repolarisation occurs as a result of inactivation of K+ channels.
The refractory period in ventricular muscle corresponds approximately to the plateau phase of the action potential.
Depolarisation is initiated by rapid entry of Na+.

Explicación

Pregunta 55 de 84

1

Cardiac stroke volume may be defined as

Selecciona una de las siguientes respuestas posibles:

pre-load minus afterload
afterload minus pre-load
end-diastolic volume (EDV) minus end-systolic volume (ESV)
end-systolic volume (ESV) minus end-diastolic volume (EDV)
peak ejection pressure minus diastolic pressure

Explicación

Pregunta 56 de 84

1

Which ONE choice indicates three events that occur at about the same time
during the cardiac cycle?

Selecciona una de las siguientes respuestas posibles:

AV valve closure, second heart sound, ventricular diastole.
semilunar valve closure, first heart sound, ventricular diastole.
semilunar valve closure, second heart sound, ventricular systole.
AV valve closure, first heart sound, ventricular systole.
AV valve closure, first heart sound, ventricular diastole.

Explicación

Pregunta 57 de 84

1

According to Poiseuille’s equation, reducing a blood vessel’s diameter by 20% would reduce blood flow in the vessel by (approximately):

Selecciona una de las siguientes respuestas posibles:

40%
80%
60%
20%
50%

Explicación

Pregunta 58 de 84

1

What is occurring during ventricular ejection?

Selecciona una de las siguientes respuestas posibles:

The AV and semilunar valves are closed as ventricular pressure is increasing.
The AV valves are open and the semilunar valves are closed as ventricular pressure is increasing.
The AV valves are open and the semilunar valves are closed as blood is leaving the ventricles.
The AV valves are closed and the semilunar valves are open as blood is leaving the ventricles.
The AV and semilunar valves are open as blood is leaving the ventricles.

Explicación

Pregunta 59 de 84

1

A patient absorbs 300ml/min of oxygen. The oxygen content of blood taken from the femoral artery = 18ml/100ml and blood taken from the pulmonary artery has an oxygen content of 13ml/100ml. If the patient has a heart rate of 60 beats/min, the patient’s stroke volume is:

Selecciona una de las siguientes respuestas posibles:

100ml.
120ml.
80ml.
10ml.
12ml.

Explicación

Pregunta 60 de 84

1

Which ONE of the following statements is INCORRECT? Increased sympathetic nervous system activity to the sinoatrial node:

Selecciona una de las siguientes respuestas posibles:

decreases the slope of the spontaneous depolarisation of these action potentials.
results in a less negative membrane potential at the end of repolarisation.
allows threshold to be reached more quickly.
causes an increase in heart rate.
increases the frequency of action potentials generated.

Explicación

Pregunta 61 de 84

1

Closure of the aortic valve is associated with all of the following except:

Selecciona una de las siguientes respuestas posibles:

rapid filling of the left ventricle.
the second heart sound.
relaxation of the ventricle.
T-wave of the ECG.
dicrotic notch on the aortic pressure wave.

Explicación

Pregunta 62 de 84

1

Myocardial contractility

Selecciona una de las siguientes respuestas posibles:

is increased by adrenaline
is increased by parasympathetic stimulation
is decreased by sympathetic nerve stimulation
cannot be altered under any circumstance
cannot be altered by changes in heart rate

Explicación

Pregunta 63 de 84

1

According to Poiseuille’s equation, blood flow in a vessel would be reduced by half when:

Selecciona una de las siguientes respuestas posibles:

the pressure gradient along the length of vessel is doubled.
blood flow velocity is doubled.
blood viscosity is halved.
vessel diameter is halved.
vessel length is doubled.

Explicación

Pregunta 64 de 84

1

An increase in myocardial contractility will result in:

Selecciona una de las siguientes respuestas posibles:

decreased end-systolic volume and increased stroke volume.
increased end-systolic volume and increased stroke volume.
increased end-diastolic volume and increased stroke volume.
no change in end-systolic volume or stroke volume.
decreased end-diastolic volume and decreased stroke volume.

Explicación

Pregunta 65 de 84

1

Key mechanisms in combating orthostatic or postural hypotension include:

Selecciona una de las siguientes respuestas posibles:

reduced distensibility of leg veins compared to thoracic veins.
the baroreceptor reflex.
muscle pumps.
all of the above.
none of the above.

Explicación

Pregunta 66 de 84

1

Blood flow velocity is slowest in because this is where is greatest.

Selecciona una de las siguientes respuestas posibles:

veins, cross-sectional area
aorta, cross-sectional area
capillaries, resistance
arterioles, resistance
capillaries, cross-sectional area

Explicación

Pregunta 67 de 84

1

Pre-load is equivalent to

Selecciona una de las siguientes respuestas posibles:

Ventricular end-systolic volume (ESV)
Peak ejection pressure
Ventricular end-diastolic volume (EDV)
Stroke volume
Right atrial pressure

Explicación

Pregunta 68 de 84

1

Which ONE of the following organs/tissues receives the greatest increase in systemic blood flow during exercise?

Selecciona una de las siguientes respuestas posibles:

Muscle.
Heart.
Brain.
Kidneys.
Skin.

Explicación

Pregunta 69 de 84

1

Which ONE of the following statements regarding blood vessels is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

Arterioles contain smooth muscle in their walls.
Capillaries contain smooth muscle in their walls.
Arteries contain large amounts of elastic tissue in their walls.
Arterioles are sometimes called resistance vessels.
Veins are sometimes called capacitance vessels.

Explicación

Pregunta 70 de 84

1

Myogenic mechanisms involved in autoregulation of blood flow are activated by:

Selecciona una de las siguientes respuestas posibles:

generation of local vasoactive substances.
the [K+] in surrounding tissue.
endothelium-derived vasoactive factors.
the [O2] in surrounding tissue.
altered intra-luminal blood pressure.

Explicación

Pregunta 71 de 84

1

Stimulation of the heart by sympathetic nerves

Selecciona una de las siguientes respuestas posibles:

results in inhibition the baroreceptor reflex
results in activation of the baroreceptor reflex
causes tachycardia
causes bradycardia
has no effect on cardiac function

Explicación

Pregunta 72 de 84

1

Compared to sinoatrial cells, ventricular contractile cells will have:

Selecciona una de las siguientes respuestas posibles:

A more negative resting membrane potential
A smaller amplitude action potential
A slower conduction velocity
An action potential with a shorter duration
A slower depolarisation during the action potential

Explicación

Pregunta 73 de 84

1

Which ONE of the following statements about an action potential generated from a sinus nodal fibre is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

The unstable baseline can be partly attributable to a progressive decrease in Ca2+ permeability.
The sudden upstroke (depolarisation) is due to the opening of Ca2+ channels causing a rapid influx of Ca2+ into the cell.
Repolarisation is in part due to activation of K+ channels.
The unstable baseline can be partly attributable to a progressive spontaneous reduction in membrane permeability to K+.
The resting membrane potential is about -60 mV.

Explicación

Pregunta 74 de 84

1

Which ONE of the following is INCORRECT regarding the mechanism by which the substance moves across the wall of a capillary?

Selecciona una de las siguientes respuestas posibles:

Respiratory gases permeate rapidly, because they are lipid soluble.
Net water transport depends upon net (hydraulic) filtration pressure.
Oxygen permeation is more than 1000 times faster than glucose permeation.
Glucose is carried across the wall by plasma filtration.
Urea diffuses across the wall down its concentration gradient.

Explicación

Pregunta 75 de 84

1

Which ONE of the following statements about the conduction system of the heart is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

Purkinje fibres have the fastest rate of conduction of all parts of the conducting system.
Electrical events can spread directly between atria and ventricles through gap junctions.
The atrioventricular node has a slower inherent rate of discharge than the sinoatrial node.
The Bundle of His receives impulses from the atrioventricular node.
The sinoatrial node is the normal pacemaker of the heart.

Explicación

Pregunta 76 de 84

1

Which ONE of the following is responsible for the rapid depolarization phase of an action potential within the pacemaker cells?

Selecciona una de las siguientes respuestas posibles:

An increase in PK+
A decrease in PK+
An increase in PCa2+
An increase in PNa+
A decrease in PNa+

Explicación

Pregunta 77 de 84

1

In cardiac muscle, the action potential in the ventricles:

Selecciona una de las siguientes respuestas posibles:

is due to an increase in chloride permeability.
has an unstable resting membrane potential.
is shorter than the action potential of a pacemaker cell.
has a resting membrane potential of about -60mV.
relies on an increase in calcium permeability.

Explicación

Pregunta 78 de 84

1

Starling’s Law of the Heart means that when ventricular pre-load is increased, stroke volume will

Selecciona una de las siguientes respuestas posibles:

decrease momentarily, then increase over time
increase
stay the same
decrease
increase momentarily, then decrease over time

Explicación

Pregunta 79 de 84

1

During the rapid ejection phase of the cardiac cycle, which ONE of the following statements is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

The aortic pressure is rising.
The mitral valve is closed.
The ventricular pressure approaches its maximum
The aortic valve is open.
The ventricular volume is at its lowest.

Explicación

Pregunta 80 de 84

1

The greatest proportion of blood volume is present within which ONE of the following vessel types?

Selecciona una de las siguientes respuestas posibles:

Pulmonary blood vessels
Heart
Systemic capillaries
Systemic arteries and arterioles
Systemic veins and venules

Explicación

Pregunta 81 de 84

1

Stimulation of the heart by parasympathetic nerves

Selecciona una de las siguientes respuestas posibles:

results in activation of the baroreceptor reflex
results in inhibition the baroreceptor reflex
causes tachycardia
causes bradycardia
has no effect on cardiac function

Explicación

Pregunta 82 de 84

1

The repolarisation of pacemaker cells is due in part to:

Selecciona una de las siguientes respuestas posibles:

a decrease in the permeability of sodium.
an increase in the permeability of calcium.
a decrease in the permeability of potassium.
an increase in the permeability of sodium.
an increase in the permeability of potassium.

Explicación

Pregunta 83 de 84

1

Which ONE of the following is true of the ventricular filling phase of the cardiac cycle?

Selecciona una de las siguientes respuestas posibles:

Ventricular pressure is increasing.
Ventricular pressure is greater than atrial pressure.
Ventricular pressure is less than aortic pressure.
All valves in the heart are open.
Ventricular filling occurs during systole.

Explicación

Pregunta 84 de 84

1

The major mechanism(s) controlling the diameter of arteries in the skeletal muscle is

Selecciona una de las siguientes respuestas posibles:

myogenic mechanisms
extracellular K+ concentration
accumulation of metabolic waste products
extracellular CO2 concentration
all of the above

	Creado por Lawrence Kwan hace más de 8 años

PHSL2101 Finals Question Bank

PHSL2101 Finals

PHSL2101 Finals

Pregunta 1 de 84

Golgi tendon organs:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 2 de 84

Reflexes

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 3 de 84

The traces below show action potential recordings from nine different peripheral afferent fibres. Which ONE of the following physical stimuli is most likely to have caused the observed pattern of activity?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 4 de 84

Choose the CORRECT statement. The vestibular system:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 5 de 84

Which ONE of the following statements is CORRECT with regard to the organisation of the spinal cord and peripheral nervous system?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 6 de 84

Shown in A and B are the action potentials generated in a single tactile afferent over 1s, under two different conditions. The alteration in response from A to B is due to a change in the applied stimulus. The stimulus change that best accounts for the response change from A to B is:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 7 de 84

Inhibitory synapses from a GABA-ergic neuron:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 8 de 84

Which ONE of the following statements about optical defects is CORRECT?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 9 de 84

Choose the best option from the following table about spindle and Golgi tendon organ afferents.

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 10 de 84

Which ONE of the following statements about motor pathways is CORRECT?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 11 de 84

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 12 de 84

Which ONE of the following statements about cerebrospinal fluid is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 13 de 84

Which ONE of the following statements is CORRECT with regard to sensory receptors and afferents? Sensory receptors and afferents characterised as “rapidly adapting” or “phasic”:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 14 de 84

A person with normal vision except for anomalous trichromacy (red-green colourblindness):

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 15 de 84

In transducing mechanical energy into a neural signal, the cochlear hair cells:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 16 de 84

During normal voluntary muscle contraction (alpha and gamma co-activation):

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 17 de 84

Which ONE of the following statements about cerebrospinal fluid (CSF) is CORRECT?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 18 de 84

With regard to the organisation of somatosensory cortex:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 19 de 84

Which ONE of the following statements about the photoreceptors of the retina is CORRECT?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 20 de 84

With regard to spinal motor neurons:

Which ONE of the following statements is CORRECT with regard to the
organisation of the spinal cord and peripheral nervous system?

Choose the best option from the following table about spindle and Golgi tendon
organ afferents.