CBNS 124 Midterm 2/video que

What sensory modalities are subserved by the spinothalamic pathways (STT)? Select all that apply.

a) nociception

b) crude touch

c) temperature

d) fine touch

e) propioception

a, b, c

Which of the following statements is TRUE about the (anterolateral) spinothalamic pathway?

a) fibers from second order neurons decussate at the medulla

b) fibers from third order neurons project to the contralateral somatosensory cortex on the frontal lobe

c) The sensory receptor afferent fibers have large axonal diameters and fast conduction velocities.

d) Cell bodies of the third order neurons are located in the ventral posterior (lateral and medial) nuclei and the intralaminar nucleus of the thalamus.

d) Cell bodies of the third order neurons are located in the ventral posterior (lateral and medial) nuclei and the intralaminar nucleus of the thalamus.

The neospinothalamic pathway, the classical spinothalamic pathway, is also known as the anterolateral pathway because

a) Fibers from second order neurons travel in the ventral and lateral portions of the spinal cord white matter.

b) Fibers from second order neurons travel in the ventral and lateral portions of the spinal cord gray matter.

c) Fibers from first order neurons project and travel anteriorly in the dorsal columns.

d) Cell bodies of third order neurons are located in the ventral posterolateral thalamus.

a) Fibers from second order neurons travel in the ventral and lateral portions of the spinal cord white matter.

The paleospinothalamic pathway has which of the following propoerties?

a) divergence due to bilateral fiber projections

b) distributes pain information broadly

c) activates limbic system

d) uses spinoreticular and spinotectal tracts

e) all of the above

e) all of the above

Which pathway in the spinothalamic trio allows for greatest discriminative function and somatotopic organization allowing for best localization of pain?

a) neospinothalamic pathway

b) trigeminal thalamic pathway

c) paleospinothalamic pathway

d) archispinothalamic pathway

a) neospinothalamic pathway

Collectively, nociceptive signals traveling through the trio of spinothalamic pathways can reach which telencephalic, diencephalic, and mesencephalic structures? Select all that apply.

a) insular cortex

b) cingulate cortex

c) S1

d) hypothalamus

e) periaqueductal gray

all (noiciceptive signals traveling through the trio of spinothalamic pathway can reach all listed brain regions)

First order neurons of the spinothalamic pathway send fibers in Tract of Lissauer that synapse onto second order neurons in the substantia gelatinosa ONLY at the level of the spinal segment where they entered. (T/F)

False (nociceptive signals enter spinal cord at one dermatome level, but also ascend and descend one or two spinal segments before penetrating gray matter of dorsal horn. This allows for broader distribution of nociceptive info but also reduces the ability for spatial discrimination of nociceptive signals.

For the VPL of the thalamus (check all that apply)

a) It receives discriminative fast pain signals from body (below neck)

b) It relays nociceptive information to the primary somatosensory cortex (S1)

c) It activates diffuse cortical areas involved in alertness and arousal

d) it is part of the anterior division of thalamus

a, b

Which of the following are functional properties of the spinothalamic pathway

a) Fine two-point discrimination

b) Poor temporal fidelity

c) Good temporal fidelity

d) Limited dissemination within cortex

b) Poor temporal fidelity (The STT pathway relays its modalities relatively slow

A Brown-Sequard patient with a hemisection of the RIGHT thoracic spinal cord will most likely suffer from the following deficits BELOW the lesion:

a) loss of touch sensations on the right side, loss of pain and temperature sensations on the left side, paralysis of left side

b) loss of touch sensations on right side, loss of pain and temperature sensations on the left side, paralysis of right side

c) loss of touch sensations on the left side, loss of pain and temperature sensations on the left side, paralysis of right side

d) loss of touch sensations on the left side, loss of pain and temperature sensations on the right side, paralysis of right side

e) loss of touch sensations on the left side, loss of pain and temperature sensations on the right side, paralysis of left side

b) loss of touch sensations on right side, loss of pain and temperature sensations on the left side, paralysis of right side (a lesion on the right side of the spinal cord will cut first order fibers arriving from right dermatome via DCML pathway and second order fibers coming from left dermatomes via spinothalamic pathway. Motor fibers descending from upper levels of NS will also be cut causing inability go produce movement (paralysis) on right (ipsilateral) side

Most cell bodies of first-order neurons that send fibers from face to CNS via cranial nerve V are located in

a) substantia gelatinosa

b) thalamus

c) trigeminal ganglia

d) tract of Lissauer of spinal cord

c) trigeminal ganglia

Dull aching, slow nociceptive (pain) signals from the face are carried by which type of sensory receptor neuronal fibers?

a) C fibers in trigeminal pathways

b) Fast conducting fibers

c) A delta fibers in trigeminal pathway

d) Fibers having axons with large diameter

a) C fibers in trigeminal pathways

The trigeminal sensory system for tactile, pressure, and vibration signals from the face processes signals that

a) originate in somatosensory receptor neurons with A delta fibers

b) involve second order neurons in the spinal trigeminal nucleus in the pons, medulla, and spinal cord

c) involve second order neurons in the mesencephalic nucleus of the trigeminal nerve in midbrain

d) terminate in VPM of thalamus which sends fibers to S1

d) terminate in VPM of thalamus which sends fibers to S1

In comparison to tactile signals, nociceptive signals from body and face

a) are more specifically targeted

b) project broadly to more brain areas

c) do not terminate in S1

d) terminate in VPM of thalamus

b) project broadly to more brain areas

What are the lines of evidence that somatosensory cortex is on the post central gyrus? Select all that apply.

a) ablation of S1 leads to astereognosia and loss of proprioception

b) stimulation of specific regions on S1 in conscious (unanesthetized) surgical patients revealed sensations from specific body parts

c) Anatomical experiments show that S1 region receives dense inputs from somatosensory neurons in VPM and VPL of thalamus

d) recording experiments show that neurons in S1 cortical columns responds to stimulation of sensory receptors in skin.

all of them

When the physician let go of the patient's legs, the patient's left leg fell. Given that this patient has Brown-Sequard Syndrome, what do the results of the physical exam likely indicate?

a) The patient's left leg is paralyzed; this is due to a left-sided lesion of the DCML pathway.

b) The patient's left leg is paralyzed; this is due to a left hemisection of the spinal cord.

c) The patient has left-sided tactile agnosia; this is due to a left-sided lesion of the DCML pathway.

d) The patient has left-sided tactile agnosia; this is due to a left hemisection of the spinal cord.

b) The patient's left leg is paralyzed; this is due to a left hemisection of the spinal cord.

What sensory modality is the physician testing for when rubbing the patient's legs or poking the patient's legs with a sharp object? Given that the patient has a left-sided spinal cord lesion, and using your knowledge of the anatomy of the DCML and STT pathways, what sensory deficit(s) should be observed?

rubbing the patient's legs tests the patient's vibration sensation, while poking his legs with a sharp object tests his pain sensation. With a left-sided lesion, the patient should have a deficit in vibration sensation on the LEFT and a deficit in pain sensation on the RIGHT.

based on this patient's history and physical exam findings of his foot (loss of toe proprioception and motor deficits on LEFT and loss of pain and temperature on RIGHT), where do we expect the lesion to be, and why?

a) On the right side of the spinal cord; because the patient has a left foot drop

b) On the right side of the spinal cord; because the patient has left-sided motor and DCML-related deficits and right-sided STT-related deficits

c) On the left side of the spinal cord; because the patient has left-sided motor and DCML-related deficits and right-sided STT-related deficits

d) On the left side of the spinal cord; because the patient has a left foot drop

c) On the left side of the spinal cord; because the patient has left-sided motor and DCML-related deficits and right-sided STT-related deficits

What are the properties of the somatotopic map?

a) The face and mouth are disproportionately smaller.

b) The body parts are not represented in a continuous fashion.

c) The map lacks organization, and all body parts are represented globally by S1.

d) It can be found in thalamus but not S1.

b) The body parts are not represented in a continuous fashion.

Whisker pairing leads to loss of discrimination between tactile stimuli coming from two different whiskers because

a) Barrel representation on S1 increases

b) Whiskers cannot be deformed easily

c) Representation for 2 barrels in S1 is fused into on

d) Tactile signal from the affected area on the snout is lost leading to a degenerated barrel

c) Representation for 2 barrels in S1 is fused into on

Which of the following statements is/are TRUE for secondary somatosensory cortex (S2)?

a) Ablation leads to amorphosynthesis

b) Allows for the ability to recognize objects by feeling

c) Has simple receptive fields that are stimulated by either the size, shape, or texture of the tactile stimulus

d) Like the posterior parietal cortex S2 neurons prefer increasingly complex tactile stimuli

what broadmanns area is hemineglect?

5, 7

How do peripheral chemical mediators enhance nociceptive signaling?

a) The response of 1st order nociceptive sensory receptors is enhanced by Substance P that is auto-released.

b) Bradykinin directly activates nociceptive receptors.

c) ATP increases the permeability of skin blood vessels leading to ischemia, further skin damage and activation of nociceptors.

d) arachidonic acid directly interacts with nociceptors.

a) The response of 1st order nociceptive sensory receptors is enhanced by Substance P that is auto-released.

Glutamatergic transmission can be modulated by other neurochemicals

a) Through Substance P binding to postsynaptic neurokinin receptors that prolong GLU-induced depolarization

b) Through release of nitric oxide from the presynaptic terminal that then binds to postsynaptic glutamate receptors

c) Through binding of Substance P on postsynaptic glutamate receptors

d) through the binding of NMDA to postsynaptic glutamate receptors

a) Through Substance P binding to postsynaptic neurokinin receptors that prolong GLU-induced depolarization

Multi-gated TRP channels

a) They are thought to be involved in neuropathic pain and inflammation-induced hyperalgesia

b) They are located on 2nd order nociceptive sensory neurons in the substantia gelatinosa

c) They flux anions that hyperpolarize presynaptic terminals of 1st order nociceptive sensory

d) Activation enhances glutamate release onto substantia gelatinosa neurons and increases sensitivity to pain

e) A and D

e) A and D

Which of the following factors can inhibit the activity of nociceptors?

a) capsaicin

b) prostaglandins

c) K+

d) ATP

e) TRPV1 channel blocker

e) TRPV1 channel blocker

Besides sensation of pain at S1, what other targets do nociceptive signals have?

a) Hypothalamus to allow for the sensation slow pain

b) Spinomesencephalic tract that process discriminative pain

c) Spinothalamic tract that produces emotional changes

d) Spinal cord motor neurons that control reflex responses to nociception

d) Spinal cord motor neurons that control reflex responses to nociception

The Mezlack-Wall gate theory refers to:

a) A descending (from brainstem) pain suppression system.

b) Non-noxious input suppresses nociceptive signaling at the spinal cord

c) Analgesia produced after simulation of extreme mechanical stimulation

d) The control system that suppresses pain via inhibitory interneurons in S1

e) The ability to evoke pain with nociception

b) Non-noxious input suppresses nociceptive signaling at the spinal cord

Which of the following non-noxious stimuli can modulate nociceptive signaling locally within the spinal cord?

a) Application of capsaicin to the damaged skin area

b) Application of Bengay to the cranium for penetration into S1 region

c) Inhibition of spinal inhibitory interneurons by cold thermoreceptive C fibers

d) Activation of spinal inhibitory interneurons by skin mechanoreceptors

d) Activation of spinal inhibitory interneurons by skin mechanoreceptors

Electrical stimulation of the periaqueductal gray matter (PAG) should produce ALL of the following EXCEPT

a) pain

b) analgesia

c) release of endorphins into the spinal cord

d) synaptic stimulation of the raphe nucleus

a) pain (stimulation of the PAG interferes with nociceptive signals and can block pain)

Which of the following leads to increased nociception?

a) central release of endogenous opioids called enkephalins

b) stimulation of PAG or raphe nucleu

c) moderate cold stimuli at the same site of injury

d) naloxone

d) naloxone (blocks opiate receptors)

Which statement is TRUE about anesthesia and analgesia?

a) Anesthetized patients are unconscious in addition to having analgesia

b) Immobilization is seen in both analgesia and anesthesia

c) Analgesics sometimes produce amnesia

d) Analgesics are sometimes called sedatives

a) Anesthetized patients are unconscious in addition to having analgesia

Pain without nociception arising from external nociceptive stimulation of painful area is exemplified by

a) Phantom limb pain

b) Referred pain

c) Neuralgia

d) All of the above are correct

d) All of the above are correct

The physical property of sound that is perceived as loudness is sound _____________.

a) frequency

b) intensity

c) pitch

d) wave

b) intensity

Which species can hear vocalizations at ultrasonic frequencies (> 70kHz)?

a) humans

b) mice

c) elephant

d) frogs

e) cat

b) mice

The force amplification process described in class is produced by ____________ and is necessary because ____________.

a) ear canal, sound must vibrate tympanic membrane intensely

b) Eustachian tube, sound waves diffuse into mouth and loose intensity

c) ossicles, impedance to sound is greatest in inner ear

d) fulcrum of middle ear, pressure inside cochlea must decrease in order to overcome inertia of fluid

c) ossicles, impedance to sound is greatest in inner ear

Transduction in the cochlea occurs in

a) hair cells

b) auditory sensory neurons connected to hair cells

c) tectorial membrane

d) cranial nerve 8

a) hair cells

Which of the following statements is CORRECT about the acoustic reflex?

a) It protects the cochlea from loud sounds occurring at ALL times.

b) It decreases the dynamic range of hearing.

c) It allows one to discern speech better in a noisy environment.

d) It allows one to discern sound at low frequencies when background sound is > 1kHz.

c) It allows one to discern speech better in a noisy environment.

For the Rinne test

a) a positive outcome is a sure sign that there is no hearing loss

b) a positive outcome can indicate sensorineural deafness if both air and bone conduction are similarly low

c) a negative outcome can indicate sensorineural deafness

d) a positive outcome may represent ossification of stapes (otosclerosis)

Save

b) a positive outcome can indicate sensorineural deafness if both air and bone conduction are similarly low

The Place Code refers to

a) a method of encoding for sound intensity

b) the orderly representation of sound frequencies preferred by an auditory structure

c) tonotopy only in the basilar membrane

d) location of the source of sound

The tips of hair cells project into the scala media, containing endolymph, while the base borders the ___________ containing perilymph.

a) scala media

b) scala tympani

c) scala vestibuli

d) stria vascularis

b) scala tympani

The endocochlear potential is produced as a result of

a) an 80 mV voltage potential difference between endolymph and perilymph

b) the low levels of K+ inside hair cell

c) biphasic receptor potential of the hair cells

d) K+ channels on tips of hair cells

a) an 80 mV voltage potential difference between endolymph and perilymph

What is the significance of MET channels?

a) they refer to the tip link that connects all stereocilia on a hair cell

b) they transduce mechanical deformation of basilar membrane into a receptor potential

c) they are voltage gated Na+ channels

d) they allow K+ (and Ca2+) to flow into the hair cell when stereocilia bend towards the shortest one

b) they transduce mechanical deformation of basilar membrane into a receptor potential

The hyperpolarizing phase of the biphasic receptor potential

a) is due to closing of MET channels

b) results from adaptation

c) is due to K+ current flowing out of the tips of hair cell

d) is due to K+ current flowing out of the tips of hair cell

a) is due to closing of MET channels

Cochlear amplification

a) is due to the outer hair cells

b) occurs in connection with transduction

c) occurs because electrical changes during transduction trigger mechanical changes in hair cell that changes resonance (displacement) of basilar membrane

d) is an active process known as electromechanical transduction (EMT)

e) all of the above are correct

e) all of the above are correct

Glutamate release from hair cells is greater as a result of ___________.

a) Greater MET channel closing during transduction

b) depolarization during transduction

c) hyperpolarization during transduction

d) tonic firing after transduction has triggered action potentials

b) depolarization during transduction

The immense hearing fidelity of the auditory system is due, in part, to the relationship between hair cells and the spiral ganglion cells (SCGs) because

a) each SGC gets auditory signals from more than one inner hair cell

b) All SCGs receive auditory signals from many outer hair cells

c) 95% of all SCGs receive auditory information from outer hair cells

d) 5% of all SCGs receive auditory information from inner hair cells

e) None of the above explain this feature

e) None of the above explain this feature

Characteristic frequency is a feature of the receptive field of

a) Inner hair cells

b) Outer hair cells

c) All auditory neurons in the auditory pathway

d) Only neurons in A1 where isofrequency bands are located

c) All auditory neurons in the auditory pathway

Auditory neurons with binaural receptive fields are found in

a) basilar membrane

b) cochlear nucleus

c) superior olive

d) A1

e) all but A and B

e) all but A and B

Temporal summation on the basilar membrane refers to more neurons firing when larger wider area on the basilar membrane is activated. (T/F)

False

Intensity coding of loud sounds (whether they are of low or high frequency) interfere with frequency coding at the basilar membrane. (T/F)

true

Phase-locking with volley can't occur at high sound frequencies (>4kHz)

a) because of the intrinsic variability of neuronal action potentials

b) because it is not required since high frequency sounds can't be heard by humans.

c) and therefore tonotopy is used instead.

d) because neurons either fire in response to every sound wave or not at all.

e) A and C

e) A and C

A louder sound will produce which of the following?

a) displacement of basilar m. that is larger at apex than at base where softer sounds are encoded

b) activation of dorsal vs ventral cochlear auditory pathway

c) interference with tonotopy only at levels above superior olivary n.

d) activation of more auditory sensory neurons including spiral ganglion cells (spatial summation)

d) activation of more auditory sensory neurons including spiral ganglion cells (spatial summation)

The location of continuous sounds of high frequency are detected by

a) interaural time delay

b) interaural time delay of phase of sound wave

c) interaural intensity difference

d) two of the above

c) interaural intensity difference

Binaural auditory neurons are located in

a) Cochlear nucleus

b) Superior olive nucleus

c) Inferior colliculus

d) A1

e) All but A are correct

e) All but A are correct

Which binaural neurons will get activated when location of a sudden sound is directly in front of the head?

a) Those detecting 0 msec interaural time delay

b) Those detecting 0.3 msec interaural time delay

c) Those detecting 0.45 msec interaural time delay

d) Those detecting 0.6 msec interaural time delay

e) none of the above

a) Those detecting 0 msec interaural time delay

Coincidence detection in binaural neurons requires which process below?

a) Arrival of auditory signals originating in LEFT auditory nerve

b) Arrival of auditory signals originating in RIGHT auditory nerve

c) Spatial summation

d) All of the above

d) All of the above

Which of the following devices bypass auditory nerve damage?

a) Hearing Aids

b) Cochlear Implant

c) Bone Anchored Hearing Appliance (BAHA)

d) Penetrating Auditory Brainstem Implant (PABI)

d) Penetrating Auditory Brainstem Implant (PABI)

Why are nociceptive signals transmitted to different nervous system structures?

a) To allow activation of different responses such as autonomic responses.

b) To improve perception at the expense of mounting physiological responses that help us cope with the damaging stimuli.

a) To allow activation of different responses such as autonomic responses.

What properties of sound are encoded by processes in the auditory system?

a) frequency

b) intensity

c) origin or location

d) all of the above

d) all of the above