Internal Organization of the Spinal Cord Flashcards
What do vertical grooves mark?
External Spinal Cord
Is the following anterior or posterior spinal cord?
deep medial fissure & two anterolateral sulci where nerve rootlets emerge from the spinal cord
Anterior spinal cord
Is the following anterior or posterior spinal cord?
shallow median sulcus and two posterolateral sulci where nerve rootlets enter the spinal cord
Posterior spinal cord
Why do cervical & lumbar regions have more gray matter?
- regions innervate the limbs motor neurons for all limb muscles are located at these levels
- sensory neurons for all limb muscles are located at these levels
Why is there more white matter as you move from caudal to rostral segments?
- ascending/descending axons are being added
- cervical spinal cord has most white matter b/c it is carrying information to and from all levels of spinal cord
C8 spinal cord segment is at what vertebral level?
C6-7 vertebral bodies at level of C6 spinous process
T1 spinal cord segment is at what vertebral level?
C7-T1 vertebral bodies at level of C7 spinous process
T10-11 spinal cord segments are at what vertebral level?
T9 vertebral body at level of T8 spinous process
L2-L5 spinal cord segments are at what vertebral level?
T12 vertebral body at level of T10 spinous process
S1-5 spinal cord segments are at what vertebral level?
L1 vertebral body at level of T12 and L1 spinous processes
What is the following structure?
Located at the end of the spinal cord at L1-2 intervertebral space
Conus medullaris
What is the following structure?
long roots required for axons from termination of spinal cord to exit lumbosacral vertebral column
Cauda equina
What is the following structre?
- located inferior to end of spinalcord
- bundle of connective tissue & glia that connects the end of the spinal cord to coccyx
Filum terminale
What is the following structure?
axons of LMN cells that leave the anterolateral cord in small groups
Rootlets
Ventral rootlets from a single segment merge to form what?
Ventral root
Dorsal root sensory axons enter where in the spinal cord?
Posterolateral spinal cord via rootlets
Dorsal root ganglion contains what
Cell bodies of sensory neurons
Sensory axons with large-diameter fibers transmitting propriocetive and touch info. are located medially or laterally?
Medially
Sensory axons with small-diameter fibers transmitting nociception and temp. information are located medially or laterally?
Laterally
How is spinal cord organized?
Segmentally
What part of the spinal cord is this?
Spinal nerve roots exit the vertebral column through intervertebral foramen above correspoinding vertebra
Cervial region
C8 spinal nerve roots emerges from where?
Between C7 and T1 vertebra
After transitting through intervertebral foramen, the spinal nerve splits into 2 marking what?
End of spinal region and beginning of peripheral nervous system
What does the dorsal rami innervate?
Paravertebral muscles, posterior parts of vertebrae and overlying cutaneous areas
What does the ventral rami innervate?
Skeletal, muscularm and cutaneous areas of limbs & anterior & lateral trunk
What type of neruon is this?
neurons that begin and end within the spinal cord
Propriospinal nerve