m2-3 quiz Flashcards
Mechanical stimuli excite mechanoreceptors in the skin by activating what type of membrane receptor?
A. TTX sensitive sodium channels B. Trp channels C. Mechanosensitive ion channels D. G protein coupled receptors E. STOML3 protein
C. Mechanosensitive ion channels
Central and peripheral vestibular disorders can be differentiated by
A. investigating gaze-evoked nystagmus
B. investigating antisaccades
C. performing a head-shaking nystagmus maneuver
D. eliciting the VOR manually in the patient
E. analyzing whether spontaneous nystagmus is suppressed by fixation or not
E. analyzing whether spontaneous nystagmus is suppressed by fixation or not
The “neural integrator” in the brainstem and cerebellar flocculus
A. Transforms a saccade velocity signal into a tonic signal for gaze holding in eccentric positions
B. Is involved in generating vergence eye movements
C. Determines saccade velocity by integrating activity of neurons in oculomotor nuclei
D. Controls the vestibulo-ocular reflex
E. Controls accuracy of saccades
A. Transforms a saccade velocity signal into a tonic signal for gaze holding in eccentric positions
Mechanical stimuli excite mechanoreceptors in the skin by exciting what type of membrane receptors?
A. Voltage gated calcium channels B. Trp channels C. TTX insensitive sodium channels D. G protein coupled receptors E. Mechanosensitive ion channels
E. Mechanosensitive ion channels
Slowly adapting type II receptors …. (indicate true statement)
A. fire irregularly to sustained mechanical stimuli
B. enable us to localize indentation stimuli very accurately
C. are associated with Merkel cells in the skin
D. evoke no sensory perception when stimulated alone
E. are very sensitive to vibration
D. evoke no sensory perception when stimulated alone
Mechanical stimuli excite mechaoreceptors in the skin by exciting what type of membrane ion channels?
A. TRP-V1 vanilloid receptor B. Mechanosensitive cation channels C. TTX insensitive voltage gated sodium channels D. A voltage gated calcium channel E. Metabotropic glutamate receptors
B. Mechanosensitive cation channels
Which of the following eye movements changes images of the environment on the fovea?
A. Smooth pursuit B. Vergence C. Fixation D. Saccades E. Vestibulo-ocular reflex
D. Saccades
Referred pain
A. Arises as a result of activity in sensory neurons innervating the viscera
B. Localizes the site of visceral injury very accurately
C. Indicates no underlying pathology and should be ignored
D. Is mediated by nociceptors that innervate simultaneously skin and visceral tissue
E. Is the empathic feeling we have when others are in pain
A. Arises as a result of activity in sensory neurons innervating the viscera
Retinal information in V1 is initially segregated in:
A. In layers
B. Columns and layers
C. In columns and layers but only for the retinal M ganglion cells
D. In columns and layers but only for the retinal P ganglion cells
E. In columns
B. Columns and layers
From the primary visual cortex (V1) information is conveyed further into the visual cortical system by two main pathways.
Which one is true?
A. None from the above.
B. The ventral pathway mainly processes spatial information.
C. The WHAT pathway projects towards the temporal cortex.
D. The WHAT pathway projects towards the parietal cortex.
E. The dorsal pathway mainly processes object recognition.
C. The WHAT pathway projects towards the temporal cortex.
Irrepressible bursts of involuntary saccades (“ocular flutter / opsoclonus”)
A. indicate dysfunction of the prepontine paramedian reticular formation
B. occur with lesions affecting the oculomotor nuclei
C. indicate dysfunction of omnipause neurons in the nucleus raphe interpositus
D. occur with lesions affecting Brodmann’s area 46 in the prefrontal cortex
E. are a sign of frontal eye field dysfunction
C. indicate dysfunction of omnipause neurons in the nucleus raphe interpositus
Wide dynamic range neurons…
- have axons that do not project directly to the ventroposterior lateral portion of the thalamus
- display no activity dependent plasticity
- are found exclusively in lamina I of the spinal cord
- code sensory discriminative aspects of noxious stimuli
- receive primary afferent input exclusively from nociceptive sensory neurons
- code sensory discriminative aspects of noxious stimuli
The following structure is not involved in brainstem control of saccades:
- Nucleus prepositus hypoglossi
- Prepontine paramedian reticular formation
- Nucleus principalis nervi trigemini
- Nucleus raphe interpositus
- Oculomotor nuclei
- Nucleus principalis nervi trigemini
What sensory fibre initiates the monosynaptic stretch reflex?
- Type Ia proprioceptors
- Type II golgi tendon organ receptors
- Large myelinated Aβ-fibers
- Sympathetic fibers
- Thinly myelinated Aδ-fibers
- Type Ia proprioceptors
What afferent fiber type conveys first pinch sensation?
- Thinly myelinated Aδ-fibers
- α-motorneurons
- Large myelinated Aβ-fibers
- Sympathetic efferent fibers
- Merkel disk afferent fibers
- Thinly myelinated Aδ-fibers
Slowly adapting type II receptors… (indicate true statement)
- fire irregularly to sustained mechanical stimuli
- enable us to localize indentation stimuli very accurately
- are associated with Merkel cells in the skin
- code skin stretch
- are insensitive to vibration
- code skin stretch
One of these statements is WRONG : C-fiber nociceptors…
- make direct synaptic connections only with glutamatergic interneurons within the superficial dorsal horn.
- sometimes respond to skin cooling
- can mediate flare response in the skin when activated
- are often activated by algogenic chemicals
- never respond to brush stimuli
- make direct synaptic connections only with glutamatergic interneurons within the superficial dorsal horn.
Inhibition of reflexive saccades is not:
- controlled by the dorsolateral prefrontal cortex
- visible at the patient’s bedside
- investigated by antisaccade testing
- dependent on omnipause neurons in the brainstem
- dependent on Brodmann’s area 46
- dependent on omnipause neurons in the brainstem
The perceived luminance of an object depends principally
- on the intensity of the light source
- on the colour spectrum of the light source
- on the motion speed of the object
- on the location of the object in the visual field
- on the contrast between the object and its background
- on the contrast between the object and its background
According to the dual pathway theory of cortical visual processing
- the dorsal pathway is concerned with localizing where objects are and the ventral visual pathway with identifying what the objects are
- information processed in the dorsal pathway is exclusively derived from magnocellular inputs and information processed in the ventral pathway exclusively from parvocellular inputs
- the dorsal pathway is concerned with the processing of information from the lower visual field and the ventral visual pathway with information from the upper visual field
- perceptual binding of different visual features, such as colour and motion, does not occur in humans because of segregated processing of these features in different pathways
- visual information can only reach consciousness if it is processed in both the dorsal and the ventral pathways
- the dorsal pathway is concerned with localizing where objects are and the ventral visual pathway with identifying what the objects are
The perceived luminance of an object depends principally
- on the intensity of the light source
- on the colour spectrum of the light source
- on the motion speed of the object
- on the location of the object in the visual field
- on the contrast between the object and its background
- on the contrast between the object and its background
It is possible to exclusively stimulate Pacinian corpuscle afferent neurons in humans
- by injection of capsaicin into the skin
- by applying a low amplitude 50 Hz stimulus to the skin
- by applying a very small amplitude high frequency vibration to the skin.
- by applying a very large amplitude low frequency vibration to the skin
- by shouting very loud
- by applying a very small amplitude high frequency vibration to the skin.
Conscious visual perception
- involves activation of the pineal gland
- can be thought of as a one-to-one mapping of the visual input in the human brain
- is independent of a priori knowledge and expectations
- is an active interpretive process that involves multiple processing stages in the human brain
- is best explained by a multistage feedforward process
- is an active interpretive process that involves multiple processing stages in the human brain
Conscious visual perception
- involves activation of the pineal gland
- can be thought of as a one-to-one mapping of the visual input in the human brain
- is independent of a priori knowledge and expectations
- is an active interpretive process that involves multiple processing stages in the human brain
- is best explained by a multistage feedforward process
- is an active interpretive process that involves multiple processing stages in the human brain