Nervous Tissue Flashcards
nerve
Neuro
nerve cell. properties of excitation, conduction, and secretion
Neuron
chemical released at the distal end of a neuron, a messenger
Neurotransmitter
towards
“af”
away
“ef”
afferent. message towards the brain
Sensory neuron
efferent, message away from the brain
Motor neuron
between
Inter
neuron between sensory and motor found only in the CNS
Interneuron
electrical and chemical means to send messages QUICKLY from cell to cell
Nervous system
Of our 11 systems, which two systems maintain internal communication/coordination?
nervous system (electrochemical) and endocrine (hormones in the blood)
What are the 2 subdivisions of the nervous system?
Central nervous system (brain and spinal cord) and peripheral nervous system (nerves and rest of nervous system)
The peripheral nervous system is divided into what divisions?
sensory and motor division
skin, muscle, bone joint
somatic subdivision
thoracic and abdominal organ. heart, lung, stomach and bladder
visceral subdivision
prepares the body for action (fight or flight)
sympathetic
rest and digest
parasympathetic
digestive tract has a nervous system of its own know as?
enteric nervous system
What are the functional classes of neurons?
Sensory (afferent) neurons, interneurons, motor (efferent) neurons
AKA soma. cell body contains the nucleus
neurosoma
receives signals from receptors (1-1000s)
dendrites
rapid conduction of nerve signal to target cell
axon
where the axon originates and where threshold occurs
axon hillock
cytoplasm of the axon
axoplasm
plasma membrane of the axon
axolemma
spiral layer of insulation
myelin sheath
production of myelin sheath
myelination
outermost layer (ending) of the myelin sheath
neurilemma
myelin covered segment
internode
gap between the myelin sheath segments
node of ranvier
bulbous end that forms the synapse with the target cell
axon terminal (terminal button)
space between 2 neurons, between the axon terminal and the target cell
synapse
Where are neurotransmitters released at?
the synapse
generate energy for neuron
mitochondria (presynaptic)
packages of neurotransmitters that will be released into the synapse by a process know as exocytosis
vesicle (presynaptic)
receives signal through synapse from neurotransmitters
receptors (postsynaptic)
How do we stop the signal?
reabsorbtion, diffusion, enzyme breakdown (synapse clearance)
bulb body, like octopus, up to 15 arms, attach to nerve fibers to form myelin sheath
oligodendrocytes (CNS Neuroglia)
resemble cuboidal ciliated epithelia that line the brain and SC, secrete/move CSF
ependymal (CNS Neuroglia)
macrophages that develop from WBC and seek out debris, will become clustered when there is an injury, trauma, or stroke
Microglia (CNS Neuroglia)
covers brain and nerves except synapse in gray mater. 90% of brain tissue. forms framework, monitors stimuli/blood flow/glucose
Astrocytes (CNS Neuroglia)
myelin sheath (PNS Neuroglia)
schwann cells
surround the soma of neurons, provide electrical insulation, regulate chemical environment (PNS Neuroglia)
Satellite cells
multi dendrite, one axon, most common, brain, SC (CNS)
multipolor
single process leading away from soma, bypasses the soma to the SC, sensory
unipolar
one dendrite, one axon, found in retina of eye
bipolar
multi dendrite, no axon, found in brain
anaxonic
