Spinal Nerve and Back Anatomy Flashcards
Sensory/afferent
carries information from body INTO the CNS
General somatic afferent (GSA)
sensations from the body such as touch, pain, temperature, proprioception and kinesthesia (perception of position and movement of muscles and joints).
general visceral afferent (GVA) / autonomic
sensations that are not usually perceived but monitor basic body functions. may perceive sensations from organs in pain
special afferent (SA)
senses of light, smell, hearing, and equilibrium
Efferent / motor modality
neurons that carry information FROM the CNS to the body
General somatic efferent (GSE)
motor control of skeletal muscle
general visceral efferent (GVE) / Autonomic nervous system
motor control of smooth muscle and glands of the viscera, heart and blood vessels, etc
Nucleus
A collection of nerve cell bodies within the central nervous system
ganglion
collection of nerve bodies outside the central nervous system
Components of a spinal cord
The spinal cord have projections of dorsal (sensory) and ventral (motor) rootlets that go on to form their perspective roots.
- Cell bodies for dorsal nerves are located in the dorsal root ganglia (DRG).
- Cell bodies for ventral root motor fibers lie within the spinal cord
Ventral roots and dorsal roots eventually merge forming a spinal nerve.
Spinal nerves (mixed nerve) have dorsal ramus (mixed nerve) and central ramus (mixed nerve) projections.
somatic afferent neuronal pathway
Exteroceptive sensation and proprioceptive sensation
Ventral ramus serves the ventrolateral trunk and limbs
Dorsal ramus serves the posterior trunk
the pathway for both ventral and dorsal ramus input goes down the dorsal root, into the Dorsal root ganglion (DRG) then onwards to the dorsal horn of the spinal cord
somatic efferent neuronal pathway
pathway starts in cell body located in the ventral horn of the spinal cord.
pathway goes though ventral root into the spinal nerve where it can go through the ventral ramus (ventrolateral thunk and limbs) or dorsal ramus (posterior trunk)
Association neurons
reside in the spinal cord and interact with the afferent and efferent spinal nerve neuron.
neurons in ascending pathways transmit sensory information to higher CNS levels
neurons in descending pathways transmit somatic and visceral motor signals from higher levels to motor neurons forming spinal nerve
short interneurons mediate reflexes within the spinal cord
intervertebral disc
disc that allows the body of the vertebrae to bend against each other but prevents them from touching
zygapophysial joints
bind together the superior articular process and inferior articular process that allows the lumbar vertebrae to from a chain
vertebral ligaments
anterior and posterior longitudinal ligaments run the length of the column and are attached to the vertebral bodies and intervertebral discs
ligamentum flava connect adjacent laminae and fill the posterior side of the spinal canal