Descending Pathways

Question 1

Where does the anterior corticospinal tract cross?

Answer 1

spinal cord

- to terminate in the anterior gray column of the spinal cord segments in the cervical and upper thoracic regions

Question 2

From the cortex, the descending fibers converge in the _______ and then pass through the _______ limb of the internal capsule.

Answer 2

corona radiata

posterior limb of IC

Question 3

At the posterior limb, CST fibers that are closest to the genu are concerned with which portions of the body?

Answer 3

Cervical

Question 4

At the posterior limb, CST fibers that are located more posteriorly are concerned with which portions of the body?

Answer 4

lower limbs

Question 5

Part of the midbrain where the CST passes?

Answer 5

Basis pedunculi

Question 6

At the pons, the CST is broken into many bundles by:

Answer 6

transverse pontocerebellar fibers

Question 7

In the medulla, the bundles of CST are group together in which portion or aspect of the medulla?

Answer 7

lower anterior border

Question 8

The fibers of the corticonuclear tract ARISE from neurons in the

Answer 8

primary motor cortex
secondary motor cortex
frontal eye field

Question 9

Fibers of the frontal eye field are located in which gyrus?

Answer 9

middle frontal gyrus

Question 10

Fibers from the frontal eye fields influence eye movements indirectly by synapsing on cells in the:

Answer 10

superior colliculi
pretectal nuclei
accessory optic nuclei of the midbrain

Question 11

Fibers from the frontal eye fields project directly, or by way of another relay in the ___________, to the nuclei of the oculomotor, trochlear, and abducens nerves

Answer 11

pontine reticular formation

Question 12

Fibers from the facial region of areas 4 and 6 terminate on internuncial neurons adjacent to the motor neurons that innervate the _____________ muscles, either of somatic or branchiomeric origin.

Answer 12

non-extraocular striated skeletal muscles

Question 13

The part of the hypoglossal nucleus that supplies the __________ muscle receives corticonuclear fibers only from the opposite cerebral hemisphere

Answer 13

genioglossus

Question 14

Which reticulospinal tract descends bilaterally?

Answer 14

Lateral (medullary) RST

Question 15

Which reticulospinal tract descends ipsilaterally?

Answer 15

Medial (pontine) RST

Question 16

RST from which part of the brainstem descend through the anterior white column?

Answer 16

Pons

Question 17

Which tract facilitates the activity of the flexor muscles?

Answer 17

Rubrospinal tract

Question 18

Where is red nucleus situated?

Answer 18

Situated in the tegmentum of the midbrain at the level of the superior colliculus

Question 19

The spinal lemniscus is located in which part of the midbrain?

Answer 19

tegmentum

Question 20

This tract is believed to be an important indirect pathway by which the cerebral cortex and the cerebellum can influence alpha and gamma motor neuron activity

Answer 20

Rubrospinal tract

Question 21

The nuclei situated in the pons and medulla oblongata beneath the floor of the fourth ventricle

Answer 21

Vestibular nuclei

Question 22

The vestibular nuclei is beneath which ventricle?

Answer 22

Fourth ventricle

Question 23

Axons of the Deiter’s nucleus descend in which part of the spinal cord?

Answer 23

Anterior column

Question 24

Nucleus involved in movements of the head required for maintaining equilibrium

Answer 24

Medial Vestibular nucleus of Schwalbe

Question 25

Axons of the nucleus of Schwalbe descend bilaterally in the anterior column with the ______________

Answer 25

medial longitudinal fasciculus

Question 26

Origin of the tectospinal tract

Answer 26

Superior colliculi

Question 27

Tract that is concerned with reflex postural movements in response to visual stimuli

Answer 27

Tectospinal tract

Question 28

Most of the fibers of the tectospinal tract cross the midline soon after their origin and descend through the brainstem close to the _________

Answer 28

medial longitudinal fasciculus

Question 29

The olivospinal tract arises from ____________ and descend in the __________ column of the spinal cord

Answer 29

Inferior olivary nucleus

Lateral white column

Question 30

The descending autonomic fibers of this tract is concerned with the control of visceral activity

Answer 30

Olivospinal tract

Question 31

Condition usually associated with Horner’s Syndrome that can also result to Bilateral loss of pain and temperature below the level of lesion

Answer 31

Syringomyelia

Question 32

Autonomic fibers from the hypothalamus descend in the ________ column of the spinal cord

Answer 32

lateral white column of the spinal cord

Question 33

Descending autonomic fibers run in which tract?

Answer 33

Reticulospinal tract

Question 34

The higher centers of the CNS associated with the control of autonomic activity are situated in the:

Answer 34

→ cerebral cortex
→ hypothalamus
→ amygdaloid complex
→ reticular formation