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