Physiology of Nerve Fibers

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What is the primary function of cognitive processing in most cases?

To make actions involuntary

To innervate extrafusal muscle fibers

To make actions adaptive and appropriate for the particular situation (correct)

To provide information about muscle length and velocity

What type of nerve fiber is responsible for providing information about both length and velocity?

Group Ia afferents (correct)

Type A gamma

Type A alpha

Golgi tendon organ

What is the function of Type A alpha nerve fibers?

Making postural adjustments

Innervating intrafusal muscle fibers

Innervating extrafusal muscle fibers (correct)

Providing proprioception

What is the name of the specialized endings that wrap around the central portion of all three types of intrafusal fibers?

Annulospiral endings Signup and view all the answers

What is the role of volition in motor control?

Initiating movement Signup and view all the answers

What is the function of the golgi tendon organ?

Used by Ib nerve fibers Signup and view all the answers

What is the term for the unconscious processing of sensory information to adapt to the physical characteristics of the body and muscles?

Compensation Signup and view all the answers

What is the primary recipient of afferents to the basal ganglia?

Striatum Signup and view all the answers

What is the term for the clustering of motor neurons in columnar, spinal nuclei?

Motor columns Signup and view all the answers

Where do excitatory afferents to the basal ganglia arise from?

From the entire cerebral cortex and the intralaminar nuclei of the thalamus Signup and view all the answers

Which cortical areas project mainly to the putamen?

Primary motor cortex and primary somatosensory cortex Signup and view all the answers

Which nucleus receives a large input from the limbic cortex?

Nucleus accumbens Signup and view all the answers

What is the shape of the caudate nucleus?

C-shaped Signup and view all the answers

Which cortical areas project primarily to the caudate?

Other cortical areas Signup and view all the answers

What is the function of the basal ganglia in movements?

Execution of voluntary movements Signup and view all the answers

What is the site of origin of the Medullary tract?

Medullary reticular formation Signup and view all the answers

What is the main function of the striatum?

Receiving afferents from the cerebral cortex Signup and view all the answers

Where do the axons of the Tectospinal tract terminate?

Anterior funiculus of the spinal cord Signup and view all the answers

What is the function of the Medullary tract?

Initiates locomotor circuits and integrates sensory input Signup and view all the answers

Where do the axons of the Anterior corticospinal tract cross over?

Contralateral side through the anterior white commissure Signup and view all the answers

What is the site of origin of the Anterior corticospinal tract?

Primary motor cortex Signup and view all the answers

What is the destination of the axons of the Medullary tract?

Anterior funiculus of the spinal cord Signup and view all the answers

What is the function of the Tectospinal tract?

Involved in reflexive turning of the head to orient to visual stimuli Signup and view all the answers

What is the site of crossover of the Tectospinal tract?

Midline Signup and view all the answers

Which type of fibers do Group Ia afferents wrap around?

The central portion of all three types of intrafusal fibers Signup and view all the answers

What type of endings do Group Ia afferents have?

Annulospiral endings Signup and view all the answers

What type of information do Group Ia afferents provide?

Both muscle length and velocity Signup and view all the answers

Which type of afferents signal information about muscle length only?

Group II afferents Signup and view all the answers

What type of endings do Group II afferents have?

Flower spray endings Signup and view all the answers

How does the firing rate of Group Ia afferents change during muscle stretch?

It increases rapidly during the stretch and remains high at the end of the stretch Signup and view all the answers

How does the firing rate of Group II afferents change during muscle stretch?

It increases steadily as the muscle is stretched Signup and view all the answers

What is the difference in the response of Group Ia and Group II afferents during muscle stretch?

Group Ia afferents respond to muscle velocity, while Group II afferents respond to muscle length Signup and view all the answers

What is the primary function of the cerebellar deep nuclei?

Originating all outputs from the cerebellum Signup and view all the answers

Which nuclear group is the most medially located?

Fastigial nuclei Signup and view all the answers

What type of information is carried by cerebellar afferents that project to the fastigial nucleus?

Vestibular, proximal somatosensory, auditory, and visual information Signup and view all the answers

Which nucleus projects to the contralateral red nucleus?

Dentate nucleus Signup and view all the answers

What is the largest of the cerebellar nuclei?