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Flashcards in The Spinal Cord Deck (70):
1

How many spinal nerves we have ?

31 Spinal nerves

  • 8 cervical
  • 12 thoracic
  • 5 lumbar
  • 5 sacral
  • 1 coccygeal

2

Where and what are the spinal cord enlargments ?

  1. Brachial plexus (C5-T1)
  2. Lumbar plexux ( L1-S3)

3

In which part of the spinal cord motor neurons are located ?

In the grey mater of the ventral horns of the spinal cord

4

The white matter contains Which important structures ?

 

  • Tracts or faciculli which ascend or descend in the spinal cord

5

Dorsal horns are ______, and ventral horns are ______, with an intermediate segment which contains ________?

Dorsal: sensory

Ventral: Motor

Intermediate segments: Autonomic neurons of T1-L2 and S2-S4

Also contains clarkes neurons

6

The conus medullaris ends ant which level ?

 

L2

7

Nerve roots of the lumbar, sacral and coccygeal regions came as ?

Cauda equina

8

The dorsal horn neurons responnd to ______ information, information enters using _____ nerves by the dorsal _____?

Respond to sensory information

Use spinal nerves

Dorsal  roots

9

Which are the two major functions of the dorsal root neurons ?

  1. Transmit information to higher regions
  2. reflexes repsonses

10

The sensory fibers that enter thorugh the dorsal root are divided into two tpes which are ?

  1. Medial division
  2. Lateral division

11

The medial division of fibers entering the dorsal root contain which type of fibers ?

  • Proprioception
    • Ia: muscle spindle
    • Ib: golgi organs
  • Touch: a beta fibers

12

The fibers responsable of carrying pain information and cold sensation are ?

A delta fibers entering in the lateral division

13

C fibers entering the dorsal roots of the spinal cord carry which information?

Dull pain and warmth sensation

Are unmyelinated

14

Rexed laminae I-VI recieve mainly information from ?

The lateral division

15

Rexed laminae VII corresponds to ?

Autonomic neurons and cerebellar unconcious sensory

16

Motor neurons and axons arising from the are located in which lamina ?

Mainly numbre IX in the ventral horns

17

Ventral neurons contain which type of motor neurons ?

Alfa: innervate skeletal muscle, in charge of producing muscle contraction

Gamma: innervate muscle spindles

18

In the spinal cord how are topographically neurons arranged ?

 

  • Dorsally: Flexors
  • Ventral: Extensors
  • Lateral to medial: hand,forearm,arm, shoulder,trunk

19

The intermediate zone  is located in lamina ____ and contains ?

Lamina VII of T1-L2 segments

Contains:

  • Preganglionic Sympathetic neurons
  • Clarkes nucleus

20

Three neural systems are formed by _________,________ which are sensitive and one motor which is ?

  • The dorsal column system
  • Spinothalamic system
  • Upper-lower motor neuron system

21

How many neurons we need two make skeletal muscle contract voluntary ?

Two

  1. UMN
  2. LMN

22

Where are the LMN located ?

  • In the ventral horn of the spinal cord 
  • Cranial nerve nuclei in brain stem

23

Where are the UMN located ?

  • Cerebral motor cortex
  • Brain Stem (red nucleus, lateral vestibular nuclei, reticular formation)

24

How Axons of the UMN reach the LMN ?

 

By the corticospinal tract

25

Lesions of the corticospinal tract above the medulla produce contralateral lesions because ?

80-90% of the fiber Decussate in the pyramids and continue al the way down in the contralateral spinal cord.

26

Cortico sponal tract lesions abive the pyramidal decussation produce _______ weakness and below the pyramidal decussation produce ______ weakness.

contralateral

Ipsilateral

27

How many neurons are neccesary to produce skeletal muscle contraction as a reflex ?

Just the LMN

28

Alpha motor neurons innervate :

Gamma motor neurons innervate :

 

Alpha: skeletal muscle fibers

Gamma: muscle spindles

29

Deep tendon reflexes are mono or polysnaptic ?

monosynaptic

 

30

Whic segmens are being evaluated when testing the following reflexes ?

  • Patelar
  • ANkle
  • Elbow
  • Elbow

Patelar: L2-L4 the femoral nerve (cuadri)

Ankle: S1 the tibial N. (gastrocnemius)

Elbow: C5-C6 (musculocutane) biceps

Elbow: C7-C8 Radial N (Triceps)

31

The Strech reflex is ?

A basic reflex in all muscles and regulates muscle tone.

32

When we tap on a muscle ligament searching for a myotactic reflex which fibers will be in charge of receiving the signal ?

The muscle spindle is innervated by the Ia fibers

33

Ia fibers enter to the spinal cord by ______, there synapse with _______, producing ______ contraction of the stimulated muscle.

Enter through the dorsal root in the dorsal horn , the synapse with the LMN in the anterior horn prosucng contraction of the stimulated muscle.

34

When UMN neurons are lessioned what general signs are seen ?

 

  • Hyperactive muscle strech fibers
  • Clasp knife reflex due to overactive golgi organs.

35

How whe a muscle contracts the antaganist muscle relaxes ?

In the spinal cord the LMN activates the muscle and at the same time by inhibitory interneurons inhibit the antagonist muscle.

36

UMN has a net _________effect over Muscle strech fibers 

 

Inhibitory

37

Which cells are in charge of monitoring muscle tension ?

And which fibers are in charge of carrying that information ?

 

Golgi organs

Ib fibers

Stop overstreching muscle and activating  antagonist muscles.

38

A patient is examinated and presents :

  • lower limbs hypotonicity
  • Hyporreflexia
  • Fasciculations
  • no Voluntary control of muscles

LMN lession

39

UMN lesions present as ?

Spastic Paresis with :

  • Muscle hyperreflexia
  • muscle hypertonia
  • Clasp kinfe reflex
  • Babinski sign

40

A patient presents in this position:

 

Decorticate rigidity

Postural flexion of the arms ans leg extension

UMN lesion

41

A patient presents tthis posture :

 

Decerebrate rigidity

Postural extension of arms and legs

42

Babinski sign is ?

UPN lesion indicator in the corticospinal tract.

Extension of the great toe and fanning of other toes.

 

43

Which are the two sensory pathways in the spinal cord ?

 

  1. Dorsal column or medial lemniscal system
  2. NAterolater
  3. Anterolateral system or spinothalamic tract

44

Sensory pathways use how many neurons ?

3 neurons

45

  • vibration
  • Pressure
  • Touch
  • consious propioception
    • THIS INFORMATION IS CARRIED BY ?

Dorsal column tract

46

The spinothalamic pathway carries inoformation regarding ?

Temperature and Pain

47

Location of the three neurons of the sensory pathways :

1st Neuron: DRG

2nd: Brain stem or spinal cord (decussates)

3rd: Thalamus

48

COMPLETE REGARDING THE DORSAL COLUMN:

  1. Fibers preentering the spinal cord :
  2. Sensation form lower trunk and lower limb is carried by ?
  3. Sensation form upper trunk and upper  limb is carried by ?

  1. FIbers : A beta fibers of the medial division
  2. Fasciculus gracilis (below T6)
  3. fasiculus cuneatus(above T5)

49

The dorsal columns ascend and synapse in the second neurons in the ________,________ respectively, then cross midline at the level of _______, as ______ fibers.

They continue as the medial _______, to the thalamus  to synapse with the third neuron in  ________.

Gracilis and cuneatus nucleus

At the level of the medulla as arcuate fibers

Continue to the thalamus as the medial lemniscus.

3Rd neuron: Ventroposterolateral nucleous of the thalamus.

50

A lesion of the dorsal columns produce ?

  • Loss of joint position sensation
  • Loss of vibratory sensation
  • Loss of pressure sensation
  • loss of two point discrimination

51

How we evaluate a dorsal column lesion ?

  1. Vibration
  2. Romberg sign

52

Positive romberg sign

Ask patient to place feet together, if theres a marked deterioration of posture with the eyes closed is positive.

53

A patient has balance problems with eyes open.

Lesio  of the dorsal columns ?

NO

Cerebellar damage

54

A unilateral lesion in the spinothalamic tract causes ?

 

Contralateral loss of pain and temperature no matter where the lesion is .

But the anesthesia begins 1-2 segments below the lesion.

55

The second neuron of the spinothalamic tract is located in ?

The dorsal hoen of grey matter

 

56

How the cerebellum gets information about unconcious proprioceptive ?

 

By the spinocerebellar tract

57

Degeneration of :

  • Spinocerebellar tract
  • Dorsal columns
  • corticospinal tracts
  • cerebellum

IS COMMONLY SEEN ?

 

Friedrich Ataxia

Autosomal recessive

58

Lesion of the spinocerebellar tract causes ?

Ataxia of gait

Patient doesnt know where their limbs are

59

Clarke nucleus and external cuneate nucleus transmit iformation of the ?

Spinocerebellar tracts

60

If we see a cut of the spinal cord with large ventral horns could be ?

 

Cervical enlargement : C5-T1

Lumbosacral enlargment : L2-S2

61

If in a spinal cord section dorsal comuns help us identify section . HOW?

Two columns present: Above T5

Justo one: below T5

62

Lateral horns are present in sections?

T1- L2

63

If no lateral segments are present in a spinal cord section might be ?

C1-C8

L3-S5

64

Brown Sequard manifestations

Hemisection of the spinal cord

  • Ipsilateral spactic weakness and below the lesion
  • Ipsilateral loss of vibration, pressure, touch sensation below the lesion
  • Loss of pain and temperature contralateral which begins two levels down the lesion.
  • Ipsilateral loss of pain and temperature (level of lession)

65

POLIO CHARACTERISTICS

  • Bilateral degeneration of LMN
  • Flaccid paralysis
  • Fasciculations
  • Areflexia

more common at lumbar levels

66

Bilateral degeneration of dorsal roots

Degeneration of dorsal columns

Impaired vibration, pression, astereognosis,ataxia

diminished reflexes.

TABES DORSALIS

 

67

  • Paresthesias
  • Pain
  • polyuria related to ?

 

Tabes dorsalis

Hypersensitivity to pain

Bladder sensation altered (present either polyurea or retension)

68

Argyl Robbertson pupils

Accomodation reflex but not ligh reflex of pupils

TABES DORSALIS

69

Cavitation of the spinal cord

Loss of pain and temperature at the level of the lesion.

Posteriorly: Muscle weakness and flaccid paralysis

SYRINGOMELIA

Usually cervical

first compress the medial fibers that give rise to the spinothalamic tract

Grows: compress the anterior horns

70

AMYOTRHOPHIC LATERAL SCLEROSIS

  • Affect LMN-Corticospinal tracts
    • spastic paralysis in lower limbs
    • increased tone and reflexes
    • flaccid paralysis in lower limbs
  • Progressive muscular atrophy
  • Common in cervical enlargment