Basics: Neuroanatomy Flashcards
Types of fibers contained within muscle spindles include…
A. Dynamic nuclear bag fibers B. Dynamic nuclear chain fibers C. Group Ib afferent fibers D. Extrafusal fibers E. Group IV afferent fibers
A. Dynamic nuclear bag fibers
Nuclear chain fibers signal only static muscle length.
Group Ib afferents are associated with Golgi tendon organs.
Extrafusal fibers are outside the muscle spindle.
Group IV afferent fibers are not part of the muscle spindle.
Muscle force is controlled in part by…
A. Alpha-gamma coactivation B. Intrafusal fibers C. Rate code D. Golgi tendon organs E. Gamma motor neurons
C. Rate code
Alpha-gamma coactivation ensures that muscle spindles maintain sensitivity to stretch over a wide range of muscle lengths.
Intrafusal fibers do not contribute significantly to muscle force.
Golgi tendon organs signal information about muscle force, but do not control that force directly.
Gamma motor neurons innervate intrafusal fibers, which do not contribute significantly to muscle force.
The lateral corticospinal tract…
A. Undergoes a 50% decussation in the caudal medulla.
B. Arises exclusively from the primary motor cortex.
C. Is an uncrossed pathway.
D. Plays a major role in the fine control of distal musculature.
E. Terminates primarily in the posterior (dorsal) horn.
D. Plays a major role in the fine control of distal musculature.
In reciprocal excitation of the Golgi tendon reflex, stimulation of…
A. Ia afferent fibers causes inhibition of synergistic muscles.
B. Ib afferent fibers causes inhibition of antagonist muscles.
C. Ia afferent fibers causes inhibition of antagonist muscles.
D. Ib afferent fibers causes excitation of antagonist muscles.
E. Ia afferent fibers causes excitation of muscles on the contralateral side.
D. Ib afferent fibers causes excitation of antagonist muscles.
Ia afferents innervate the muscle spindle
Ib afferents inhibit the homonymous muscle
Betz cells are most abundant in layer…
A. IV of somatosensory cortex. B. V of somatosensory cortex. C. IV of motor cortex. D. V of motor cortex. E. III of motor cortex.
D. V of motor cortex.
A corticospinal neuron in primary motor cortex can do all of the following EXCEPT:
A. Project to multiple motor neuron pools in the spinal cord.
B. Participate in the initiation of movement.
C. Code for the amount of force of individual muscles.
D. Code for the direction of movement.
E. Code for the extent of movement.
C. Code for the amount of force of individual muscles.
This is a FALSE statement. Motor cortex neurons code for the force of individual movements, not individual muscles. Lower motor neurons (alpha motor neurons) encode the force of individual muscles.
Which of the basal ganglia nuclei receive direct cortical input?
A. Claustrum and amygdala.
B. Centromedian nucleus and subthalamic nucleus.
C. Substantia nigra pars compacta and globus pallidus external.
D. Globus pallidus internal and substantia nigra pars reticulata.
E. Caudate and putamen.
E. Caudate and putamen.
All of the following statements about the basal ganglia are correct EXCEPT:
A. The net effect of excitation of the direct pathway is to inhibit cortex.
B. Dopaminergic neurons of the substantia nigra signal unexpected reward or unexpected absence of reward.
C. The basal ganglia have both motor and cognitive functions.
D. The subthalamic nucleus is the origin of the only purely excitatory pathway within the basal ganglia intrinsic circuitry.
E. Parkinson’s disease results from damage to the basal ganglia.
A. The net effect of excitation of the direct pathway is to inhibit cortex.
This is a FALSE statement. The net effect of excitation of the direct pathway is to excite cortex.
The spinocerebellum contains the…
A. vermis and intermediate zone of the anterior and posterior lobes.
B. Vermal and floccular parts of the flocculonodular lobe.
C. Lateral portions of the cerebellum.
D. Posterior lobe and interposed nuclei.
E. Anterior lobe and dentate nuclei.
A. vermis and intermediate zone of the anterior and posterior lobes.
The lateral vestibular nuclei are functionally analogous to the…
A. Red nucleus B. Purkinje cells C. Basal ganglia D. Thalamus E. Deep cerebellar nuclei
E. Deep cerebellar nuclei
The lateral vestibular nuclei, although not contained within the cerebellum, are considered to be functionally analogous to the deep cerebellar nuclei because of their functional connectivity with the cerebellum.
Following a strenuous workout with his neighborhood team, a right-handed, 52-year-old former professional basketball player awoke the next morning with paralysis of the right lower extremity. A neurological exam revealed an exaggerated stretch reflex. There was no disturbance of position sense, pain sensation or tactile discrimination. Where is the problem localized?
A. Anterior (ventral) horn, right side.
B. Cerebellum, right side.
C. Posterior (dorsal) columns of spinal cord, right side.
D. Left motor cortex, lateral (inferior) portion of motor map.
E. Left motor cortex, medial (superior) portion of motor map.
E. Left motor cortex, medial (superior) portion of motor map.
All of the following are examples of dyskinesia EXCEPT:
A. Athetosis B. Chorea C. Tremors D. Rigidity E. Ballismus
D. Rigidity
Rigidity is not an involuntary movement.
A patient is capable of pupillary constriction during accommodation but not in response to a light directed to either eye. The lesion is most likely present in the…
A. optic nerve B. abducens nucleus C. Edinger-Westphal nucleus D. pretectal areas E. supraoculomotor nucleus
D. pretectal areas
The pretectal area provides bilateral input to the Edinger-Westphal nucleus for the direct and consensual pupillary light response.
Edinger-Westphal is incorrect as damage to this nucleus would diminish the pupil response both to light and during accommodation.
The pontine paramedian reticular formation is involved in which of the following?
A. Vestibular nystagmus B. Optokinetic nystagmus C. Saccades D. Smooth pursuit E. Accommodation
C. Saccades
The frontal eye field neurons send control signals to the pontine paramedial reticular formation for voluntary horizontal eye movements (i.e., to direct the eyes toward an object of interest on or command to direct the gaze to the left or right).
A 57-year old male with a past history of high blood pressure awakens with a terrible headache. His eyes tend to drift about and when he is asked to track a pen moving to his left, both eyes move in short, jerky steps. In contrast, both eyes move smoothly when his eyes track a pen moving to his right. Given the patient’s history, a radiological study is scheduled to determine whether a stroke had occurred. The study determines the area of infarction to include which of the following?
A. Left abducens nerve B. Left medial longitudinal fasciculus C. Right frontal lobe D. Right temporal lobe E. Left temporal lobe
E. Left temporal lobe
Neurons in the left temporal lobe (middle superior and middle temporal gyri) are involved in detecting movement of objects in space and in guiding tracking eye movements during smooth pursuit. The left tracking movement is jerky because the frontal eye field is being used to guide the eye movement in saccades. The two eyes move to the left and if the object isn’t in view, the eyes make another saccade to direct them towards the expected position of the moving object.
What are the 2 structures involved in reward circuit that are thought to mediate drug addiction?
Ventral tegmental Area and Nucleus accumbens
Which opiate receptor class is involved with spinal analgesia?
Kappa (K)
How many opioid receptors available? What are those?
4
- Delta (δ)- involved with analgesia, antidepressant effects, and physical dependence.
- Kappa- involved in spinal analgesia, sedation, miosis, and inhibition of antidiuretic hormone release.
- Mu- involved in supraspinal analgesia and physical dependence; respiratory depression, miosis, euphoria, reduced gastrointestinal motility, and physical dependence
- ORL1/orphanin (or nociceptin receptor)- involved in anxiety, depression, appetite, and development of tolerance to mu agonists.
How many are Glutamate receptors and what are those?
4:
- NMDA receptor
- Kainate receptor
- AMPA receptro
- Metabotropic receptor
NMDA receptros are highly concentrated in which part of the hippocampus?
CA1 pyramidal neurons of the (Sommer Sector)
Which explains its vulnerability to hypoxia, hypoglycemia and epilepsy
What is the other term for CA4?
Is it resistant or vulnerable to hypoxia?
Bratz sector
Vulnerable
What is the importance of the dorsomedial nucleus?
It has projections to dorsolateral prefrontal, orbitofrontal, anterior cingulate gyrus, and temporal lobe/amygdala.
Dysfunction results in abulia, anterograde amnesia, social disinhibition and motivation loss
Anterior nucleus of thalamus is involved in…
limbic relay and memory formation (part of Papez circuit)
What is the importance of the pulvinar nucleus?
The pulvinar is involved in processing visual info and sensory integration.
