Spinal Cord

Front 1

Regarding the development of the spinal cord, gray matter develops from the ___ zone and white matter develops from the ___ zone

Back 1

Intermediate

Marginal

Front 2

The alar and basal plates in the developing spinal cord are separated by the ____ ____.

Together, the alar and basal plates are considered which zone

Back 2

sulcus limitans


Mantle Zone

Front 3

The alar lamina will become the ___ ___. The basal lamina will become the ___ ___.

Back 3

Dorsal horns

Ventral horns

Front 4

The central area between the horns of the spinal cord is known as what?

This area contains neurons with what type of function?

Back 4

Intermediate grey commissure

Neurons have both motor (autonomic preganglionic) and sensory (Clarks column, origin of spinocerebelllar tracts)

Front 5

Ventral roots leave the cord from what area?

Dorsal roots enter the cord from what area?

Back 5

Anterolateral sulcus

Posterolateral sulcus (dorsal entry zone)

Front 6

(T/F) The Posterior intermediate sulcus is only found in lower portions of the spinal cord

Back 6

False. It is found only in thoracic and cervical spinal cord. This structure lies between the posterior median and posterior lateral sulci.

Front 7

Spinal nerves C1-C7 pass (above/below) the correspondingly numbered vertebra.

Thoracic vertebra pass (above/below) correspondingly numbered vertebra

Back 7

Above

Below

Front 8

Together the arachnoid mater and the pia mater are known as what

Back 8

leptomeninges

Front 9

Pachymeninx is another word for what?

Back 9

dura mater

Front 10

(T/F) Arachnoid mater is a delicate membrane with plentiful vessels that help supply the dura mater and spinal cord

Back 10

False. The arachnoid mater is an avascular membrane.

Front 11

Dorsal horn is composed of laminae _ - _, Lamina __ forms the intermediate zone, and the ventral horn consists of laminae __ - __.

Back 11

I - VI.
VII forms the intermediate zone

VII - IX forms the ventral

* X is surrounding the central canal

Front 12

Which lamina receive nociceptive input via lightly or unmyelinated small diameter afferents?

Back 12

Lamina I (aka posteromarginal nucleus) and V

Front 13

Lamina I and V receive what?

Back 13

nociceptive input via lightly or unmyelinated afferents

Front 14

Lamina III and IV receive what

Back 14

non noxious input via myelinated, large diameter afferents

Front 15

Lamina II is also called what?

What does it receive?

Back 15

Substantia gelatinosa

nociceptive afferents (C fibers) and collaterals from large diameter afferents. This is the site of first order sensory processing

Front 16

Which lamina receive non noxious input via myelinated, large diameter afferents

Back 16

III and IV

Front 17

What lamina is the site of first order sensory processing?

Back 17

II

Front 18

Lamina VI

Back 18

receives input from descending motor pathways and proprioceptive input from the periphery

Front 19

Where is the nucleus dorsalis of Clarke found?

What input does it receive?

Back 19

In the dorsal medial part of lamina VII at spinal cords C8-L2.

Receives proprioceptive input from muscle and sends axonal projections to the ipsilateral cerebellum (dorsal spinocerebellar tract)

Front 20

Sacral autonomic nuclei found in S2-S4 give rise to what?

Back 20

preganglionic parasympathetic

Front 21

Lamina VIII

Back 21

contains primarily interneurons, they relay and integrate segmental and descending inputs to motor neurons

Front 22

Lamina IX is the ....

It contains large ___ ___ and small ___

Where is this area the largest?

Back 22

main somatic motor area.

It contains large alpha motor neurons and small gamma motor neurons

Largest in the cervical and lumbar spinal cord

Front 23

What structure is found in the central ventral horn of segments C3-C5? What do the neurons located here do?

Back 23

Phrenic Nucleus (lamina IX)

Provide motor to diaphragm

Front 24

Regarding the ventral horn of the Spinal cord:
The __ __ neurons of lamina IX are somatotopically organized.
Neurons that innervate ____ musculature are located dorsally, whereas those innervating ___ musculature are found ventrally

Back 24

alpha motor

FLEXOR - dorsal

EXTENSOR - ventral

Front 25

Area X receives ___ conveying visceral ___ related information. Neurons from this lamina project to higher centers via the ___ columns

Back 25

AFFERENTS

PAIN - related

DORSAL columns

Front 26

Explain what muscle spindles do

Back 26

They are intrafusal muscle fibers that are attached to extrafusal fibers and act as sensory fibers capable of detecting static and dynamic aspects of stretch in a muscle.

They contain nuclear bag fibers (dynamic) and nuclear chain fibers (static)

Front 27

Motor fibers connecting to extrafusal muscle fibers are called what?

Connecting to contractile portions of intrafusal muscle spindles?

Back 27

Alpha

Gamma

Front 28

Give an example of a descending tract that contacts gamma motor neurons.

When is this connection found useful?

Back 28

Corticospinal

This occurs in the control of muscle tone, such as in postural muscles. It allows muscles to be contracted at an unconscious level.

Front 29

Golgi tendon organs form the _____counterpart to muscle spindles. These are nerve endings near_____

Back 29

inhibitory

the musculotendinous junction

These neurons activate inhibitory interneurons that will inhibit alpha motor neurons in order to prevent strong contractions.

Front 30

The spinal white matter is composed of myelinated axons organized into _____

Back 30

tracts (fasciculi).

Front 31

Where is the anterior white commissure found and what does it do?

Back 31

Dorsal end of the anterior median fissure.

It is a major PAIN pathway, neurons that contribute to the anterolateral system cross here. It is found in the cervical and thoracic regions

Front 32

The posterior spinal arteries usually originate from the _____

Back 32

posterior inferior cerebellar arteries.

Front 33

The spinal grey matter is predominantly supplied by the central branches of the _____. This includes most areas of the ___ and ____ horns.

Back 33

Anterior Spinal Artery


Ventral and Intermediate

Front 34

most vascular lesions that directly affect motor neurons involve the _____

Back 34

anterior spinal artery.

Front 35

Which tract differentiates touch, vibration, form recognition, joint and muscle sensation, conscious position (proprioception)

Back 35

Actions of Dorsal Column-Medial lemniscus pathway

Front 36

Pathway of Dorsal Column Medial lemniscus

Back 36

First order neurons are located in the dorsal root ganglia, project fibers to fasciculus gracilis (below T6) and fasciculus cuneaus. These fibers cross and form the compact medial lemniscus, which ascends and ends in the VPL nucleus of the thalamus.

Finally, 3rd order neurons starts in the VPL and end at the somatosensory cortex (3,1,2)

Front 37

Which tract is responsible for Light touch (ie. Cotton wisp)

Back 37

Ventral Spinothalamic Tract Actions

Front 38

Pathway of Ventral Spinothalamic Tract

Back 38

3 orders

dorsal root ganglia --> dorsal horn --> second order neurons cross in the ventral white commissure --> VPL nucleus --> post central gyrus (3,1,2)

Front 39

Itch, Pain, Temperature

Back 39

Lateral Spinothalamic Tract actions

Front 40

Pathway of lateral spinothalamic tract

Back 40

dorsal root ganglion --> dorsal horn -->2nd order cross at anterior white commissure -->VPL -->post central gyrus (3,1,2)

Front 41

Dorsal spinocerebellar Tract action

Back 41

unconscious proprioception, fine coordination and posture of individual muscles in the LE.

Front 42

Which tract is responisble for unconscious proprioception, Coordinated movement and posture of lower extremity

Back 42

Ventral Spinocerebellar Tract

Front 43

Dorsal spinocerebellar tract pathway

Back 43

dorsal root ganglion --> nucleus dorsalis of Clarke

This is an uncrossed tract (compared to Ventral spinocerebellar which is crossed)

Front 44

Cuneocerebellar Tract

Back 44

unconscious proprioception, fine coordination and posture of individual muscles in the UE

Front 45

tract responsible for votlitional motor, and fine skilled movements in the extremities

Back 45

corticospinal

this is part of the pyramidal system

Front 46

Tract responsible for pain, temperature, protopathic (crude) touch

Back 46

anterolateral system

Front 47

Most (80-90%) pyramidal axons cross the midline at ___and descend in the __ ___ ___.

Back 47

Foramen magnum

Lateral corticospinal tract

Front 48

The pyramidal axons that do not cross form the __ ___ ___

Back 48

anterior cortico spinal tract

This tract primarily innervates axial musculature. Specific lesions here have little clinical significance

Front 49

In general, corticospinal axons are ___ biased

Back 49

flexor

The primary function of this tract is control of fine skilled movements

Front 50

Rubrospinal tracts is ___ biased.

It originates in the ___ ___ of the ___ ___

Back 50

flexor

red nucleus of the rostral midbrain.

This tract does not extend beyond the cervical levels

Front 51

Vestibulospinal tract is ___ biased

Back 51

extensor.

It has a major effect on postural muscle activity related to balance and proximal body muscle tone.

Front 52

reticulospinal pathway is ___ biased

Back 52

extensor

It has a major effect of on postural muscle activity related to balance and proximal body muscle tone.

Front 53

The motor aspect of posture is due to ___ tract and ___ tract, both of which facilitate antigravity musculatures and maintain orientation in space.

Back 53

vestibulospinal and reticulospinal

Front 54

The hypothalamospinal tract crosses at the intermediate grey commissure (T/F)

Back 54

FALSE. This pathway is ipsilateral, ie predominantly uncrossed

Front 55

The areas of the corticospinal tract that will innervated leg areas will be ___ relative to those that innervate areas to the trunk or arm

Back 55

lateral

Front 56

Afferents traveling in the dorsal columns are somatotopically organized; afferents from the foot and leg are located ____ and the arm and neck are located ____

Back 56

medially

laterally

Front 57

Fibers for what tract enter the spinal cord in the medial division of the dorsal root entry zone

Back 57

dorsal colums

Front 58

Fibers for what tract enter the spinal cord in the lateral division of the dorsal root entry zone

Back 58

anterolateral system

Front 59

Tract that carries pain and temperature

Back 59

Lateral spinothalamic

Front 60

The anterior spinocerebellar tract crosses in the spinal cord, and the recrosses in the cerebellum (T/F)

Back 60

True. This tract carries integrated information for the whole lower limb

The Posterior spinocerebellar tract does NOT cross, it is ipsilateral