SPINAL CORD Flashcards
Length of Spinal Cord
Length of Vertebral Canal
⭐ 45 cm
⭐ 70cm
Spinal Cord Extent
Upper border of ATLAS
⬇️
L1-L2 junction
(Lower border of L1)
In children till L3 L4
Number of Vertebrae
33
C7
T12
L5
S5
Cx4
Number of SPINAL SEGMENTS
31 segments
C8
T12
L5
S5
Cx1
Development of Spinal Cord
Caudal part of Neural Tube (4th Week)
Terminal portion of Spinal Cord
Conus Medullaris
Which cranial nerves arise from Conus Medullaris
Last 4 segments
S3
S4
S5
C1
EPICONUS?
Portion of spinal cord just above Conus Medullaris
L4
L5
S1
S2
Dura meter and Arachnoid mater extend upto
🧠⚡ DAS²⚡
S2 vertebrae
Filum Terminal extends upto
🧠⚡ FIX⚡
Coccyx 1 vertebra
.
Modification of PIAMETER from tip of Conus Medullaris to Dorsum of COCCYX1
Cauda Equina
Nerves arising from the Conus Medullaris and Epiconus radiate outwards, like horse tail
⬇️
Known as CAUDA EQUINA
Formula to get Spinal Segmental level from Vertebral Level
🧠⚡ We always talk in SEGMENTAL LEVEL⚡
CAUDA Equina Syndrome
Asymmetric involvement of ROOTS
L2 S1
L3 S2
L4 S3
L5 S4
S5
Cx1
Stand on
Sit on
Stand on S1
Sit on S3
Conus Medullaris syndrome
Symmetric and B/L involvement of last 4 roots:
S3
S4
S5
Cx1
Spinal ENLARGEMENT
- Cervical enlargement (C3 to T2)
- Lumbar enlargement (L1 to S3)
Grey-White Matter Organization
⭐ Spinal Cord
⭐ Brain
🧠⚡ OPPOSITE TO EACH OTHER⚡
⭐ Spinal Cord
Grey : Inside
White: Outside
⭐ Brain
Grey: Outside
White: Inside
Grey Matter of Spinal Cord
Tracts of Spinal Cord
DCML
Dorsal Column Medial Laminiscus
DCML cross over occurs at
Anterolateral Pathway crosses over at
⭐ Medulla Oblongata
⭐ same Spinal cord Level
⭐ Medial Leminiscus
⭐ Lateral Leminiscus
⭐
⭐ DCML fibers
⭐ Internal Arcuate Fibers
⭐ External Arcuate Fibers
✨ Posterior External Arcuate Fibers
✨ Anterior External Arcuate Fibers
⭐ Internal Arcuate Fibers
🎯 DCML fibers at Medulla Oblongata
🎯 Fibers that Cross over
⭐ External Arcuate Fibers
✨ Posterior External Arcuate Fibers
🎯 Uncrossed fibers from the lateral part of the arcuate nucleus to the inferior cerebellar peduncle.
✨ Anterior External Arcuate Fibers
🎯 Fibers from the arcuate nucleus coursing over the caudal end of the olive to the caudal cerebellar peduncle. Part of the pontocerebellar tract.
Carry sensation from
⭐ Fasiculus Cuneatus
⭐ Fasiculus Gracilis
🧠⚡C comes 1st then G ⚡
⭐ Upper Limb
⭐ Lower Limb
DCML ends on Which NUCLEI IN THALAMUS?
DCML gives fibers to which NUCLEI in Spinal Cord
⭐ VPL (VENTRAL POSTEROLATERAL nucleus)
⭐ Nucleus Proprius : maintains reflex ARC
DCML fibers 3rd Order neurons pass through which limb of INTERNAL CAPSULE?
Posterior Limb of INTERNAL CAPSULE
Descending Tracts in Lateral Column
🧠⚡ RL⚡
Rubrospinal Tract
Lateral Corticospinal tract
Descending Tracts in Anterior Column
🧠⚡ A VOTe⚡
Anterior Corticospinal tract
Vestibulospinal tract
Olivospinal tract
Tectospinal tract
All tracts in spinal cord is represented in ARRANGEMENT except
🧠⚡ ML ➡️ CTLS⚡
Cervical ➡️ Thoracic ➡️ Lumbar ➡️ Sacral
⭐ Dorsal Column
ML ➡️ SLTC
SACRAL ➡️ LUMBAR ➡️ THORACIC ➡️ CERVICAL
Glove and Stocking Peripheral Neuropathy
Cervical Myelopathy
Outer Cervical column fibers affected 1st ➡️ ➡️ Inner Sacral fibers affected
ViP makes you STAND UP
⚡️VIP activates Antigravity muscles⚡️
Sit on Rubber mat
⚡️Rubber mat activates gravity muscles⚡️
- Vestibular spinal tract
- Pontine Reticulo-spinal tract
Sit down
1. Rubrospinal tract
2. Medullary Reticulo-spinal Tract
Vestibular Apparatus
Function
✨ For standing up
✨ Activates and Increases tone of ANTI-GRAVITY Muscles
Red Nucleus functions
Rubrospinal Tract
⚡️ If Red Nucleus spared: increased Gravity Muscle tone (Flexors of lower limb) As in Decorticate rigidity
Increases tone of GRAVITY muscles
Flexors of Upper limb
Inner Grey Matter
Types of Neurons
- Golgi Type I neurons: Long Axons
- Golgi Type 2 neurons: Short Axons
Decerebrate
Vs
Decorticate
Decerbrate vs Decorticate
Lesion at
Blood supply of SPINAL CORD
- Anterior Spinal Artery x1
- Posterior Spinal Artery x2
- Anterior Radiculomedullary artery
- Posterior Radiculomedullary artery
Arteria Vasa Corona
Formed by anastamosis BETWEEN Anterior and Posterior Radiculomedullary artery with Anterior and Posterior Spinal artery
Artery of Adamkiewicz
Synonyms
Artery of Adamkiewicz
Artery of Lumbar Enlargement
Arteria Radicularis Magna
Radicular artery is noticeably larger that the others, located in Lower Thoracic or Upper Lumbar
Number of RADICULAR ARTERIES
10-23 Posterior RADICULAR Artery
6-10 Anterior RADICULAR Artery
Which spinal segments not supplied by RADICULAR Arteries
C1 C2 C3 C4
Vertical WATERSHED REGION in spinal Cord
Horizontal WATERSHED REGION in spinal Cord
⭐ T3 T4 T5 T6 T7 T8 (MID Thoracic Region)
⭐ BETWEEN SUPPLY OF ANTERIOR AND POSTERIOR SPINAL ARTERY (in the LATERAL PART of SPINAL CORD)
Which tract is 1st involved in Spinal Cord Ischemia
LATERAL Corticospinal Tract
Posterior CORD Syndrome
Seen in
HYPER-EXTENSION INJURY
⭐ DCML involved only
ANTERIOR CORD SYNDROME
Seen in
✨ Anterior Spinal Artery Infarction
✨ TRAUMA
Loss of Power, Pain, Temperature
DISSOCIATIVE SENSORY LOSS
Seen in
Central CORD Syndrome
Posterior Column spared, Spinothalamic Tract involved, MOTOR and ANS involved
CENTRAL CORD SYNDROME
Seen in
Syringomyelia
Brown Sequard Syndrome
⭐ At the level of Lesion
⭐ Below the Level of Lesion
🧠💡DIM CST💡
⭐ At the level of Lesion
✨ Everything I/L Lost
⭐ Below the Level of Lesion
I/L MOTOR
I/L DCML SENSATION
C/L SPINOTHALAMIC TRACT
B/L MOTOR WEAKNESS can NEVER BE DUE To
CEREBRAL LESION
Cause: CORD
Diaphragm supply by DERMATOME
C3-C5
Phrenic Nerve
C7
Fingers.
Wrist Extensors
Triceps
C8
Little Finger: Sensory
Wrist and Finger Flexion: Motor
BEEVOR’S Sign used for
Localizing SPINAL CORD LESION to T10-11
⬇️
Upward movement of UMBILICUS when ABDOMINAL Wall Contracts
REASON for BEEVOR’S Sign
T10-T12 lesion : Paralyze the lower ABDOMINAL MUSCLES (but not UPPER abd walls)
Normally, the rectus abdominis muscle contracts as a single unit with no predominance of upper half over the lower part or left over the right side.Therefore, normally on trunk flexion, the navel does not move.
Weakness of upper part of rectus abdominis (Navel moves upward): Beevor’s sign
Weakness of lower part of rectus abdominis (Navel moves downward): Inverted Beevor’s sign