Spinal Cord and Reflexes Lecture Notes

These flashcards cover key concepts related to the anatomy and functions of the spinal cord, its associated nerves, reflexes, and other critical components of the nervous system.

Spinal Cord Functions

Relay sensory information from periphery to brain, contains motor neurons, and direct connection between motor & sensory information.

Conus Medullaris

End of the spinal cord, typically around L1-L2.

Dural Sac

Part of the dura mater that continues with the vertebral canal beyond the spinal cord.

Cauda Equina

Bundle of spinal nerves extending beyond the spinal cord, traveling to their appropriate exit points.

Filum Terminale, Internus

Thread-like extension of the pia mater from the conus medullaris.

Filum Terminale, Externus

Thread-like extension of the dura mater below the end of the dural sac, attaches to the coccyx.

Substantia Gelantinosa

Region that processes pain and temperature along the entire spinal cord.

Nucleus Proprius

Processes touch and proprioception along the entire spinal cord.

Dorsal Motor Neurons

Motor neurons in the ventral horn that innervate flexor muscles.

Ascending Tracts

Tracts that carry sensory information to the brain, including dorsal column-medial lemniscus and spinothalamic.

Descending Tracts

Tracts that carry motor commands from the brain, including corticospinal and rubrospinal.

Dermatome

Area of body's surface innervated by a single spinal nerve.

Spinal Nerve

Nerve created from the merging of the ventral root and dorsal root.

Plexus

Network formed by ventral primary rami of spinal nerves.

Motor Unit

Total number of skeletal muscle fibers innervated by one alpha motor neuron.

Reflex Arc

Pathway that includes the receptor, sensory neuron, motor neuron, and effector.

Stretch Reflex (Patellar Reflex)

Monosynaptic reflex involving muscle spindles that maintains muscle tone.

Flexor Reflex

Withdraws the body from pain via nociceptors and interneurons.

Crossed Extensor Reflex

Supports balance by activating contralateral extensors during withdrawal.