chapter 13 spinal cord Flashcards
what are the order from inner to outer most
pia matter to arachnid matter to dura matter
defn the spinal nerve
Mixed nerves—contain both afferent (sensory) and efferent (motor) fibers, Formed by union of posterior and anterior roots
defn the tracts
bundle of axons in CNS
Relay same type of information in same direction
how many white columns are there and what do each do?
Posterior white columns—between posterior horns and posterior median sulcus
Anterior white columns—between anterior horns and anterior median fissure
Lateral white columns—on each side of spinal cord, between anterior and posterior columns
defn gray commissures what goes around this area
Axons cross here to the other side of spinal cord
Sensory or motor nucleus location within gray matter determines which body part it controls
defn the nerves plexus
Complex, interwoven networks of nerve fibers
Formed from blended fibers of anterior rami of adjacent spinal nerves
Allows multiple spinal nerves to supply the same structures
what nerves comes from the brachial plexus
Musculocutaneous nerve (lateral cord)
Median nerve (lateral and medial cords)
Ulnar nerve (medial cord)
Axillary nerve (posterior cord)
Radial nerve (posterior cord)
what nerve innervates the diaphragm
the cervical plexus
what is the largest peripheral nerve
sciatic nerve
defn the dermatome
specific bilateral region of skin supplied by a single pair of spinal nerves
defn the shingles
rash/symptoms occur along dermatomes
spreads information from one neuron or neuronal pool to many
Especially common in sensory pathways
which neuron pools is this ?
Divergence
information moves along a single path, sequentially from one neuron or neuronal pool to the next
Example: pain signals pass sequentially through two neuronal pools to reach conscious brain
what neuron pool is this ?
serial processing
several neurons/neuronal pools process the same information at the same time
Example: step on a bee. Signals spread through several neuronal pools so you can shift your weight, lift your foot, yell in pain at about the same time
what neuron pool is this?
parallel processing
collateral branches of neurons extend back and continue stimulating presynaptic neurons
Forms positive feedback loop; continues until synaptic fatigue or inhibition occurs
Examples: may maintain consciousness, breathing, muscle coordination
what neuron pool is this ?
reverberating
