post lab spinal cord

• Dermatome:

  Area of skin supplied by the sensory fibers from a single spinal nerve (Specifically: Dorsal Root)
• Important Dermatomes:

  •Digits 1-2: C6

  •Digit 3: C7

  •Digits 4-5: C8

  •Nipple: T4

  •Umbilicus: T10

  •Knee: L3

  •Medial Leg:L4

  •Big Toe: L5

  •Heel: S1

  
• What is the difference between the dermatomes of the limbs and torso?

  Torso: Horizontal Bands, Segmental (T2-T12)

  Limbs: Spiral Arrangement

  
• Dermatome -

  A) C5

  B) C6

  C) C7

  D) C8

  E) T1

  F) T2

  G) C4

  H) C3

  I) C2

  J) T3

  K) T12

  L) T10

  M) T4

  N) L2

  O) L3

  P) L4

  Q) L5

  R) S1

  S) S2

  T) S3

  U) S4

  V) S5

  
• What is what

  A) dorsal

  B) ventral

  C) white matter

  D) grey matter

  E) posterior medium sulcus

  F) Anterior Median Fissure

  
• what is what

  A) dorsal

  B) ventral

  C) ventral horn

  D) dorsal horn

  E) dorsal root

  F) dorsal root ganglion

  G) ventral root

  H) mixed spinal nerve

  
• what is what

  A) Posterior Funiculi

  B) Lateral Funiculus

  C) Anterior Funiculi

  D) Lateral Funiculus

  
• Epidural Space:

  •Real Space

  •Internal Vertebral Venous Plexus & Fat
• Subdural Space:

  •Potential Space
• Subarachnoid Space:

  •Real Space

  •Cerebrospinal Fluid
• meninges layers

  A) dura mater

  B) Arachnoid Mater

  C) Pia Mater

  D) Epidural Space

  E) Subdural Space

  F) subarachnoid space

  
• When administering an epidural injection, which layers of the spinal cord does the needle pass through?

  The needle does not pass through any layers of the spinal cord because an epidural injection is inserted into the epidural space. Remember the epidural space is superficial to the dura mater of the spinal cord which is the outermost layer of the spinal cord meninges.
• When performing a lumbar puncture to collect cerebrospinal fluid (CSF), which layers of the spinal cord does the needle pass through, and which space does it enter?

  To collect CSF, the needle must enter the subarachnoid space, specifically the lumbar cistern caudal to the conus medullaris. The needle must pass through the dura mater & arachnoid mater to enter the subarachnoid space.
• Why is it important to perform both procedures at the L4/L5 level? Consider the anatomy of the spinal cord and potential risks when the needle is inserted at higher levels?

  Both procedures should be performed at the L4/L5 level to avoid any possibility of piercing the most caudal part of the spinal cord, the conus medullaris. In most people, the conus medullaris is at the L1/L2 level.
• Organize the Sections – Spinal Cord

  A) dorsal

  B) ventral

  C) cranial

  D) caudal

  E) cervical

  F) thoracic

  G) lumbar

  H) sacral

  
• Organize the Sections – Brainstem

  A) ventral

  B) dorsal

  C) cranial

  D) caudal

  E) upper midbrain

  F) lower midbrain

  G) pons

  H) upper medulla

  I) lower medulla

  
• Tract Identification – Spinal Cord

  A) DCML tract

  B) Lateral Corticospinal Tract

  C) Spinothalamic Tract

  D) Anterior Corticospinal Tract

  E) DCML Tract

  F) DCML Tract

  G) DCML Tract

  H) Anterior Corticospinal Tract

  I) Lateral Corticospinal Tract

  J) Spinothalamic Tract

  
• Tract Identification – Brainstem

  A) Spinothalamic Tract

  B) Spinothalamic Tract

  C) Spinothalamic Tract

  D) Nucleus Cuneatus

  E) Nucleus Gracilis

  
• What is the function of the spinothalamic tract?

  Information about pain, temperature, & crude touch

  
• Where does the spinothalamic tract begin & end?

  Begins: Sensory Receptors

  Ends: Primary Somatosensory Cortex

  
• Is the spinothalamic tract ascending or descending?

  Ascending because it carries sensory information

  
• How many neurons are involved in the spinothalamic tract?

  3

  
• Where does the spinothalamic tract decussate?

  Spinal Cord Entry

  
• What is the function of the DCML tract?

  Information about fine touch, 2-point discrimination, vibration, & proprioception

  
• Where does the DCML tract begin & end?

  Begins: Sensory Receptors

  Ends: Primary Somatosensory Cortex

  
• Is the DCML tract ascending or descending?

  Ascending because it carries sensory information

  
• How many neurons are involved in the DCML tract?

  3

  
• Where does the DCML tract decussate?

  Caudal Medulla Oblongata

  
• How would patients with a lesion affecting the DCML tract be different from those with a lesion affecting the spinothalamic tract?

  A patient will present with DIFFERENT sensory deficits.

  DCML Lesion:

  Patient loses fine touch, vibration, proprioception, & 2-point discrimination sensation

  Spinothalamic Lesion:

  Patient loses pain, temperature, crude touch, & pressure sensation

  
• What is the function of the corticospinal tract?

  Voluntary Movement

  
• Where does the corticospinal tract begin & end?

  Begins: Primary Motor Cortex

  Ends: Skeletal Muscles

  
• Is the corticospinal tract ascending or descending?

  Descending because it carries motor information

  
• How many neurons are involved in the corticospinal tract? What are they referred to as?

  2 neurons referred to as upper & lower motor neurons

  
• Where does the corticospinal tract decussate?

  Anterior Tract: Spinal Cord Exit Level (Postural Muscles)

  Lateral Tract: Medulla (Limb Muscles)

  
• If a patient has a unilateral right-sided corticospinal tract lesion at the lumbar level, how would they present in a clinic? Consider which side of the body would be affected and the type of deficits you might see?

  The lateral corticospinal tract would have already decussated in the medulla, so the patient would have ipsilateral motor deficits of the right lower limb.

  
• How would the patient presentation differ if the right-sided lesion were in the pons instead?

  The anterior & lateral corticospinal tracts would be traveling together and not decussated yet, therefore the patient would have contralateral motor deficits of the body below the neck on the left side.

  
• Case 1: A 58 year old man arrives at the hospital with a ruptured anterior spinal artery aneurysm at the cervical level.

  Identify the spinal cord tracts affected by this vascular injury?

  Lateral Corticospinal Tract, Anterior Corticospinal Tract, Spinothalamic Tract

  (Ventral Horns also impacted)

  
• Case 1: A 58 year old man arrives at the hospital with a ruptured anterior spinal artery aneurysm at the cervical level.

  Describe what symptoms the patient is probably experiencing?

  •Loss of pain, temperature, crude touch & pressure sensation below the neck

  •Loss of voluntary movement to limb and postural muscles below the neck

  
• Case 1: A 58 year old man arrives at the hospital with a ruptured anterior spinal artery aneurysm at the cervical level.

  Determine whether the deficits are unilateral or bilateral.?

  Bilateral

  
• Case 2: A 19 year old woman arrives at the hospital after a motor vehicle accident where her RIGHT posterior spinal artery was severed at the lumbar level.

  Identify the spinal cord tracts affected by this vascular injury?

  The right DCML tract, specifically the gracile fasciculus, is affected. The right dorsal grey horn is also affected.