What composes the central nervous system?
The brain and spinal cord
What composes the peripheral nervous system?
All nerves outside of the brain and spinal cord
Is the following stimuli somatic or autonomic?
Touch, pressure, vibration, external forces due to gravity
Somatic
What would be a type of response from the somatic nervous system to stimuli?
Voluntary control, skeletal muscle contraction and joint movement
(Ex: kicking a ball)
What does the central nervous system (CNS) do?
Processing, integration and coordination
What is the direction of the movement of information for neurons?
Dendrite -> cell body -> axon + myelin -> synapses
What is a spinal nerve?
A bundle of sensory + motor fibers emerging from the spinal cord (CNS) that carries sensory and motor signals between the body and the CNS
Sensory (afferent) -> ___
Motor (efferent) -> ___
CNS
PNS
What are spinal and (named) nerves?
Bundles of sensory and motor axons
Where are the cell bodies of sensory (afferent) neurons?
Dorsal root ganglion (DRG) which is located outside of the spinal cord
Where are the cell bodies of motor (efferent) neurons?
Anterior (ventral) horn which is located inside of the spinal cord
What are the parts of a spinal nerve in order?
rootlets -> roots -> spinal nerve -> rami
Which rootlets are closest to the spinal cord?
Anterior
What does the posterior ramus have?
Sensory and motor to intrinsic back muscles + associated skin (smaller)
What does the anterior (ventral) ramus have?
Sensory and motor to all other muscles (except intrinsic back) + skin (larger)
What is a motor unit?
One motor neuron innervating multiple muscle fibers
What are small motor units and large motor units used for respectively?
Precise control (e.g., eye muscles)
Strength (e.g., quadriceps)
_____ work together for coordinated movement
Motor units
The spinal cord ends at ____ in adults
L1/L2
What are the 3 meninges of the spinal cord? (From outermost to inner most)
1) Dura mater (outer fibrous layer, protection
2) Arachnoids mater (middle layer, cushioning)
3) Pia mater (adhered to cord/brain, suspend them to dura/arachnoid via denticulate ligaments
What are dermatomes?
Area/region of skin innervated by a single spinal nerve
What are myotomes?
A group of muscles innervated by a single spinal nerve
