Spinal Cord Flashcards
Identify the major gross anatomical regions of the spinal cord
Explain segmentation of the spinal cord
31 external segments demonstrated by 31 pairs of spinal nerves. no internal segmentation
What is the conus medularis
where the spinal cord ends (approx L1)
What is the filum terminale?
a piece of pia mater that extend all the way down spinal column and attaches to keep the spinal cord in position
What are the 2 spinal enlargements and why?
- Cervical enlargement - corresponds with innervation of arms/brachial plexus
- lunbosacral enlargement - corresponds with innevation of legs/lumbosacral plexus
What are the 3 meninges of spinal cord
- pia mater (innermost, adhered to spinal cord)
- arachnoid mater (middle, outer boundary of CSF filled subarachnoid space)
- dura mater (outer, thick tube)
What is denticulate ligament
serrated ligament of pia-arachnoid tissue called pachymeninges which suspends the spinal cord inside the dural sheath
Name the 3 white matter columns
- posterior funiculus
- lateral funiculus
- anterior funiculus
Name the 3 major descending motor tracts and their function
- Corticospinal tract
Lateral - skilled volitional movement
ventral - fine/conscious control of limbs - Vestibulospinal tract - balance and postural corrections
- Reticulospinal tract - movement not requiring dexteriry/volition or postural control
Name the 3 major ascending sensory tracts and their function
- Dorsal column medial lemniscus system - fine touch, 2-point discrimination, vibration
- Spinothalamic tract - pain, temperature, crude touch
- spinocerebellar tracts
dorsal - proprioceptive info (only above L3), through inferior cerebellar peducle
ventral - same as dorsal but through superior cerebellar peduncle
Describe the stretch reflex
- ie patellar reflex
- spindles pick up stretch, initiate quads, contract to protect it
- doesnt need brain input
- monosynaptic reflex
Describe the flexor reflex
- withdrawal in response to painful stimulus
- polysynaptic relfex
