Neuroanatomy Week 3 - Spinal Cord Flashcards
Where does the spinal cord start and end?
Foramen magnum to L1 - L2 spinal level
or Foramen magnum to conus medallaris (medullary cone)
What’s another term for anterior?
Ventral
How are the left and right spinal cord halves segregated?
- Anterior median fissure
- Posterior median septum
What does the spinal cord grey matter comprise of?
- Cell bodies of interneurons
- Unmyelinated axons
- Glial support cells
What are the 3 main divisions of the spinal horns?
- Anterior
- Posterior
- Lateral horn (intermediate)
What is the anterior part responsible for?
Motor function
What is the posterior horn responsible for?
Sensory function
What is the intermediate horn associated with?
SNS & PNS autonomic NS
What is the somatic nervous system?
- Controls voluntary moments
- Incl. afferent & efferent signals
What is central group phrenic nucleus associated with?
Mnemonic:
C3-4-5 keeps the diaphragm alive!
What is central group phrenic nucleus associated with?
Mnemonic:
C3-4-5 keeps the diaphragm alive!
What is the spinal accessory nucleus associated with?
- Is a cranial nerve
- Between C1 - C5
- Innervates trapeziuz and sternocloidomastoid
What is the lumbosacral nucleus associated with?
- Between L2 & S3
- Function - unknown
What is the marginal nucleus of the spinal cord associated with?
- In dorsal horn
- AKA posteromarginal nucleus
- Marginal zone
- Spans whole length of spinal cord
- Relays pain and thermal stimuli
What is the gelatinous substance associated with?
- Dorsal horn
- Stretches entire length of spinal cord
- Modifies sensory input transmissions
What is the nucleus proprius associated with?
- Dorsal horn
- Full length of the spinal cord
- ## Forns lateral spinothalamic tract
What is the posterior thoracic nucleus associated with?
Aka: nucleus dorsalis, Clarkes nucleus, column of Clarke
- Stretches between C8 - L3
- Receives proprioceptive feedback
- ## Gives rise to the dorsal spinocerebellar tract
Where is the lateral horn?
- Central horn within the spinal cord grey matter
- Aka intermediate zone
What 2 nuclei does the lateral horn contain?
- Intermediolateral nucleus
- Intermediomedial nucleus
What is the intermediolateral nucleus associated with?
- Within the lateral horn (intermediate zone) of the spinal cord
- Stretches between T1 & L2
- Gives rise to preganglionic sympathetic fibres
What is the intermediomedial nucleus associated with?
- Extends from S2 to S4
- Lateral horn
- Gives rise to preganglionic PNS fibres
What is the exed laminae?
- Organization of cells and fibres within the grey matter exhibiting a defined pattern
- Has 10 defined layers Lamina I - LX
What direction are sensory signals sent to the thalamus and cerebral cortex?
Rostrally
Where is the spinal cord found?
- Spinal canal of the vertebral column
What are 4 things protecting the spinal cord?
- The vertebrae
- Attaching ligaments
- Minenges
- CSF (cushioning)
What are the 3 spinal cord meninges?
- Pia mater
- Arachnoid mater
- Dura mater
What is pia mater associated with?
- Innermost meningeal layer
- Thin
- Surface of the spinal cord
What is arachnoid mater associated with?
- between subarachnoid space & dura mater
- Forms the outer boundary of the fluid-filled subarachnoid space
What is dura mater associated with?
- Thick
- outermost layer
What is the pachymeninges?
AKA The denticulate ligament
Located between Between the pia mater (inner) and arachnoid meninges (middle)
Where is the denticulate ligament?
Between the pia mater (inner) and arachnoid meninges (middle)
How many points is the denticulate ligament aka (parchymeninges) attached?
21 points
Where is the spinal cord epidural space?
- Anterior and Posterior
- Contains fat
- Offers protection
- Contains venous plexus
How many spinal cord external segments are there?
31
How many nerves and the number of vertebrae does the cervical spine segment have?
Nerves - 8
C1 - C7
What is the cauda equina?
Lumbosacral roots
Spinal cord white matter consists of what 3 columns (funiculi)?
- The dorsal funiculus
- Lateral funiculus
- Ventral funiculus
What does grey matter contain?
- Cell bodies and glia
What is the white matter of the spinal cord associated with?
Ascending or descending fiber pathways
What is the medullary cone?
the cone-shaped terminal portion of the spinal cord.
How many spinal nerves are there?
31
What does the deep ventral (anterior) median fissure contain?
- Connective tissue of the pia mater
- Anterior spinal artery
Cerebrospinal fluid can be sampled by inserting a needle into what area?
the subarachnoid space below the level of the medullary cone
What part of the spinal cord horn are motor neurons?
Ventral horn
Where do sensory axons enter the horn?
dorsal horn and the dorsal funiculi
What fasciculi does the ascending tracts include?
Gracile & cuneate fasciculi
What is the ascending crossed tract from the dorsal horn associated with sensation?
Spinothalamic tract
What are 2 descending motor tracts?
- Vestibulospinal tract
- Crossed lateral corticospinal tract
Controls skeletal muscles
What 2 fibres influence autonomic functions?
Hypothalamospinal fibres
Reticulospinal fibers
What is the The innermost meningeal layer?
Pia Mater
What is the outmost layer of the meninges?
Dura Mater
What is the epidural space predominantly filled with?
Fatty tissue
What’s the cauda equina?
Lumbosacral roots
What colour is the filum terminale?
Blue
What segements are the spinal cord cervical enlargements?
C5 - T1
What segments of the spinal cord make lumbosacral enlargement?
L1 - S4
What does substantia gelatinosa contain?
Interneurons that have a predominent role in pain
How many layers of laminae of Rexed are there?
10
