Tracts

Question 1

Tracts of the spinal cord

-definition

Answer 1

White matter connecting areas of the brain

Question 2

Ascending tracts

-names (6)

Answer 2

• Gracile fasciculus
• Cuneate fasciculus
• Dorsal and ventral spinocerebellar tract
• Anterior and lateral spinothalamic tract

Question 3

Descending tracts

-names (8)

Answer 3

• Ventral and lateral corticospinal tract
• Lateral and medial reticulospinal tract
• Tectospinal tract
• Lateral and medial vestibulospinal tract
• Rubrospinal

Question 4

Ascending tracts

-characteristics

Answer 4

Neural pathway by which sensory info from the site of stimulus (outside CNS) to the cerebral cortex
-sensory

Question 5

Descending tracts

-characteristics

Answer 5

Pathways by which motor signals are sent from the brain to the lower motor neurones
-motor

Question 6

Tracts at the posterior funiculus (2)

Answer 6

Gracile and cuneate

-all ascending (sensory)

Question 7

Tracts at the lateral funiculus (5)

Answer 7

• Lateral spinothalamic tract (S)
• Anterior and posterior spinocerebellar tract (S)
• Lateral corticospinal tract (M)
• Rubrospinal tract (M)
• Lateral reticulospinal (M)

Question 8

Tracts at the anterior funiculus (5)

Answer 8

• Anterior spinothalamic tract (S)
• Anterior corticospinal tract (M)
• Medial reticulospinal tract (M)
• Lateral and medial vestibulospinal tract (M)
• Tectospinal tract (M)

Question 9

Gracile and cuneate fasciculi

-function

Answer 9

Proprioceptive (position, sense and movement) and Exteroceptive (touch, pressure, vibration) information

Question 10

Spinothalamic tract

-function

Answer 10

Anterior spinothalamic –> touch and pressure

Lateral spinothalamic –> pain and temperature

Question 11

Spinocerebellar tract

-function

Answer 11

Proprioceptive (position, sense and movement) and Exteroceptive information (touch, pressure, vibration)

Question 12

Vestibulospinal tracts

-function

Answer 12

Excites motor neurons of extensor muscles, inhibit motor neurons of flexor muscles
-involuntary things

Question 13

Rubrospinal tracts

-function

Answer 13

Excites flexor muscles and inhibits extensor ones

Question 14

Reticulospinal tracts

-function

Answer 14

Medial: posture, crude and stereotyped movements of the limb.

Lateral: control of pain perception

Question 15

Corticospinal and cortico-nuclear tracts

-function

Answer 15

Resposible for voluntary movements

Question 16

Gracile and cuneate fasciculi

-pathway

Answer 16

1st neurons –> spinal ganglion

2nd neurons –> nucleus gracile and cuneate (gracile lower spinal segments, cuneate upper thoracic and
cervical segments)

Medial lemniscus

3rd neurons –> ventral- post lateral nucleus (thalamus)

Post- central gyrus

Question 17

Spinothalamic tracts

-pathway

Answer 17

1st neurons –> spinal ganglion

2nd neurons –> spinal cord

Fibers cross the spinal cord

Spinoreticular and spinotectal tracts

3rd neurons –> ventral post- lateral nucleus

Post- central gyrus

Question 18

Spinocerebellar tracts

-pathway

Answer 18

1st neurons –> spinal ganglion

2nd neurons –> spinal cord

Posterior spinocerebellar –> passes through inferior cerebellar peduncle
Anterior spinocerebellar –> passes through superior cerebellar peduncle
Cuneo- cerebellar tract –> passes through inferior cerebellar peduncle

Question 19

Corticospinal and cortico- nuclear tracts

-pathway

Answer 19

Precentral gyrus (primary motor area)

Crus cerebri (mid-brain)

Cortinuclear tract: nuclei of the cranial nerve, some fibers decussate, some not

Lateral corticospinal: pyramidal decussation
Anterior corticospinal: decussation in the spinal cord

Motor neurons of the anterior horn

Question 20

Vestibulospinal tracts

-pathway

Answer 20

Vestibular nuclei

Lateral (ends ipsilaterally) and medial (contains both crossed and uncrossed fibers)

Question 21

Rubrospinal tracts

-pathway

Answer 21

Red nucleus of the midbrain

Fibers cross

Question 22

Tectospinal tracts

-pathway

Answer 22

Superior colliculus of the midbrain

Turning the neck to the contralateral side from the unilateral simulation of the superior colliculus

Question 23

Reticulospinal tracts

-pathway

Answer 23

Reticular formation (medulla oblongata and pons)

Medial: ipsi- and contralateral fibers
Lateral: mostly crossed fibers