introduction to the nervous system Flashcards
what do nerves do
allow us to sense our environment - both internal and external (sensory functions)
central nervous system (CNS)
brain
spinal cord
central controller
peripheral nervous system
- all other nerve tissues not in the CNS
- spinal nerves
- cranial nerves
- autonomic nerves
- wiring
neuron
basic unit of nervous system
what are axons covered in and what does this help with
a myelin sheath which makes conduction easier
nerves
bundle of axons wrapped in connective tissue
what can a single nerve fibre do
only conduct action potentials in relation ton one modality
what are the 6 modalities
Somatic sensory function
Somatic motor function
Special sensory function
Visceral afferent function
Sympathetic function
Parasympathetic function
afferent
sensory
in a nerve what kind of modality would each axon be carrying
a mix of modalities
in motor nerves where is the action potential direction
towards body wall, body cavity or organ
what is the direction of sensory nerve
action potential towards brain
what is the outermost layer of the cerebral hemisphere
cortex
- consist of gyro and sulci
how many cranial nerves are there
12 - numbered in roman numerals
some Say marry money but my brother says big brains matter more
S = Sensory
M = Motor
B = Both
where do nerves exit/ enter the cranium
the foraminae
when can pathology affect a nerve
at any point in its course
where does the spinal cord pass through
the foramen magnum
what is the spinal cord protected by
the vertebral canal
what are the 4 segments of the spinal cord
cervical
thoracic
lumbar
sacral/coccygeal
what are the 2 enlargements of the spinal cord
cervical
lumbosacral
how does the spinal cord connect with the spinal nerves
bilaterally
where does the spinal cord end
at L1/L2 IV disc level
conus medullaris
how are spinal nerves names
according to the vertebrae above it
- except in the cervical region, where they are named according to the vertebrae below it
