6- Spinal Cord and Tracts

Question 1

Afferent Info Streams

Answer 1

Local Reflexes

To cortex

To cerebellum

Info goes to all 3 streams simultaneously

Question 2

Spinal Cord Ends At

Answer 2

Conus Medullaris at L1/L2

Question 3

Cauda Equina

Answer 3

Collection of nerve terminals (L3-S5) caudal to the conus medullaris

Formed from lower spinal nerves descending before exiting spinal cord

Question 4

Filum Terminale

Answer 4

Fibrous tissue connecting conus medullaris to coccyx

Made of pia mater- anchors spinal cord to vertebrae

Question 5

Dermatomes

Answer 5

Mesoderm—-> somites

Somites retain connectivity with originating vertebral level

Somites differentiate

Result in different regions of the body connected to different parts of spinal cord

Question 6

Lissauer’s Tract

Answer 6

Entry point of some DRG fibers

In PH

Question 7

Intermediate Gray (IG)

Answer 7

Contains interneurons adn tract cells , some autonomic pre-ganglionic MN

Question 8

Ventral Horn (VH)

Answer 8

Has motor neurons

Question 9

Substantia Galatinosa

Answer 9

Superficial zone of DH

Has nerve terminal

In PH

Question 10

Rexed Laminae

Answer 10

Defined by cellular structure

I-X

Question 11

Rexed Laminae- DH

Answer 11

I-VI

Question 12

Rexed Laminae- IG

Answer 12

VII

Question 13

Rexed Laminae-VH

Answer 13

VIII-IX

Question 14

Central Canal

Answer 14

X

Question 15

Fibers of the Spinal Cord

Answer 15

Long ascending—> thalamus, cerebellum, brainstem

Long descending–> from cortex to spinal cord

Local propriospinal- shorter fibers that interconnect different parts of spinal cord

Question 16

Spinal Tracts

Answer 16

Carries specific type of sensory/motor info

Most tracts consist of 2-3 neurons

Has a consistent location at all spinal cord level

Usually cross over at some point

Question 17

Ascending Tracts

Answer 17

Dorsal Column Medial Lemniscal

Spinocerebellar

Anterolateral (spinothalamic)

Question 18

Spinocerebellar Tract

Answer 18

Provide info from legs

Ipsilateral to cerebellum

Question 19

Cuneocerebellar Tract

Answer 19

Info from arms

Ipsilateral to cerebellum

Question 20

Reticulospinal Tract

Answer 20

Involved in locomotion and posture (need to be awake to move)

Includes pontine and medullary branches

Question 21

Tectospinal Tract

Answer 21

Orientation of head towards source of visual or auditory stimuli

Descending

Question 22

Vestibulospinal Tract

Answer 22

Centre of gravity/posture

Descending

Question 23

Raphespinal Tract

Answer 23

Pain modulation

Descending

Question 24

Symptoms of UMN Damage

Answer 24

Shock (paralysis and areflexia) followed by hyperreflexia

Question 25

Symptoms of LMN Disease

Answer 25

Paral | ysis followed by areflexia and muscle atrophy

Question 26

IG- Sympathetic Pre-Ganglionic

Answer 26

Thoracolumbar

Question 27

IG- Parasympathetic Pre-Ganglionic

Answer 27

Sacral and cervical

Question 28

Symptoms of Nerve Root Compression

Answer 28

Most common in lower cervical and lumbar regions Pin in muscle Paraesthesia (numbness) Loss of cutaneous snesory info Loss of spinal reflex