Nervous System Jackie Hernandez p.5
Parts + Functions of the spinal cord
Neurotransmitter
Cranial nerves
spinal Nerves
Reflex arc
classification of neurons
Compare and contrast autonomic NS
Tissues
Parts + function of Brain
Divisions + subdivisions
Action potential + Nerve impulses
Major Functions
Central nervous system
Effectors
receptors
sensory neurons
Motor neurons
two roots
Numbered in sequence
1st pair=mixed nerves
31 pairs
ventral
Dorsal
motor
sensory
Lumbar nerves
cervical nerves
Thoracic nerves
Sacral nerves
coccygeal nerves
12 pairs
5 pairs
8 pairs
5 pairs
Subdivisions
Peripheral Nervous system
Central nervous system
sensory fibers
automatic fibers
Somatic fibers
spinal cord
brain
Parts
Functions
spinal reflexes
transmits impulses to + from brain
ascending tracts
descending tracts
house spinal reflexes
cauda equina (horse's tail)
dorsal root ganglia
white matter
lumbar enlargement
gray matter
cervical enlargement
central canal
Posterior + anterior horns
carries motor info from brain to muscles/glands
carries sensory info to brain
unipolar neurons
Bipolar neurons
Motor neuron
Multipolar Neurons
sensory neurons
Interneurons neurons
forms links between other neurons
multipolar neurons laying with CNS
some cell bodies aggregate in nuclei
Many dendrites + 1 axon arising from body
Most neurons are multipolar (cell bodies)
found in special senses
2 processes extending from the cell body
dendrite + 1 axon
1 process extending from the cell body
splits into 2 parts function
1 axon
conduct impulses from CNS to peripheral neurons
multipolar neurons
impulses from peripheral receptors to CNS
some bipolar
usually unipolar
afferent
some neurons produce one transmitter while other produce 2 or more
actions depend on type of receptor
includes acetylcholine, amino acids, neuropeptides
more than 100 neurotransmitters
diffuse across cleft + bind to receptors on membrane
stores + released from synaptic cleft
communication accomplished by a chemical
released in response to a nerve impulses
impulse conduction
Action potential either happens or not
Saltatory conduction
continuous conduction
myelin sheath insulates axons
impulses jump from one node of ranvier to the next
occurs in myelinated axons
conduct impulses over the entire length of their membrane
occurs in unmyelinated axon
occurs when charge reaches -55mv
reached cells respond by going back to their rest place
neurons are all the same strength
neuroglia
cells that support neurons
fills space, structurally support, protect +insulate neurons
doesn't generate or conduct nerve impulses
CNS
oligodendrocytes
Microglia
function as phagocytes for bacterial cells, cellular debris + produce scar tissue for injury
small cells
forms myelin sheath around axon in brain+ spinal cord
Sensory functions
Thinking, movement, internal process of physiology
motor functions
Integrative Functions
processing info for decision making
coordination of sensory info in CNS
transport info to CNS
info travels from receptors to sensory neurons
detect internal/external changes
nerve impulses conducted along motor neurons to effectors
effectors: muscle/glands responds to decision made in CNS
Parasympathetic division
Sympathetic division
short preganglionic fibers arise from neurons in gray matter
axons exit spinal cord from ventral roots
axons leave spinal nerves proceeds into sympathetic ganglia
fight or flight senses
synapse with postganglionic neurons, long axons return to spinal nerves + proceed to visceral effector
Pf extends outward in cranial or sacral nerves
long preganglionic fibers arise from brain stem + sacral region
rest + digest
synapse in terminal ganglia in or close to visceral effectors organs
12 pairs of underside of brain
1st pair arises from cerebrum + 2nd pair from thalamus
designated by number + name (superior to inferior)
most are mixed (sensory + motor nerve fibers)
Largest + most complex portion of the NS
4 Lobes
4 main parts
brain stem
cerebellum
diencephalon
Cerebrum
parietal
occipital
tempral
Frontal
Connective tissue coverings
Epineurium
Endoneurium
Perineurium
bundles
covering around fascicles of nerve fibers
outer covering of nerves
axons
covering around individual nerve fibers