Nervous System material! Flashcards
nervous system is divided into which 2 nervous systems?
central & peripheral
peripheral nervous system aka as ? divided into what 2 big divisions?
autonomic and somatic
autonomic division is further divided into what 2 divisions?
parasympathetic & sympathetic
Major function of the neuron?
excitability (respond to stimuli)
nerve tissue consists of what 2 cells?
neurons and neuroglia
function of dendrites
input area; receives signals from other neurons
function of soma (cell body)
input area; main nutritional and metabolic area
function of axon
conductive region; generates action potential along its length
4 types of neuroglia in CNS and function of each
astrocytes- attach to blood capillaries & neurons to create blood-brain barrier, restricts movement of substances btwn blood & neurons of CNS, provide nutrients to neurons, regulate ion concentration, remove excess neurotransmitters
oligodendrocytes- produce & maintain myelin
microglia- acts as phagocytes (remove damaged nerve tissue & invading microbes)
ependymal cells- line brain ventricles & central canal of spinal cord to protect & nourish CNS, produce & asist in circulation of cerebrospinal fluid
what support cell forms the myelin sheath?
Schwann cells
myelin is found around which part of the neuron ?
axon
what substance is found in synaptic vesicles of the axon terminal
ACh acetylcholine
neurons have only one or many axons?
only one
axons are never or frequently branched?
frequently
dendrites have only one or many branches?
many
region of the cell body from which the axon originates from the cell body?
axon hillock
secretes neurotransmitters; at ends of axon
axon terminal
receptive region of a neuron
dendrite
insulates the nerve fibers
myelin sheath
site of the nucleus and most important metabolic processes
cell body (soma)
impulse transmitter
axon
3 types of functional neurons and their function
sensory (afferent) neurons - transmit impulses to CNS
motor (efferent) neurons - carry info from CNS to effectors
interneurons - contact w/ nearby neurons
bipolar vs unipolar vs multipolar
unipolar- cell body is not in direct line of axon & dendrite (pulled off to the left side of axon)
bipolar- cell body located in the middle of axon
multipolar- several dendrites with cell body in the middle of them
oligondendrocytes are located where?
they are attached to schwann cells bc they produce and maintain myelin, no projections
CNS involves what parts of the body? (2)
brain and spinal cord
PNS involves what parts of body? (5)
cranial nerves spinal nerves ganglia enteric plexuses in small intestine sensory receptors in skin
what do all neurons consist of ?
cell body, dendrites, and axon
how does information flow in neuron structure?
dendrites to cell body to axon to axon terminal to synaptic end bulbs
cell body
contains organelles typical of any other cell that maintains normal life functions
aka soma
synthesizes new cell products
dendrites
extensions of the cell body that RECEIVE information
axon hillock
site where impulses begin
cone shape at end of cell body (like wrist, triangle)
axon collateral
branch of an axon
axon
long process that conducts information to another cell (neuron effector) extends from axon hillock single axon per neuron axoplasm -cytoplasm of axon axolemma -cell membrane of axon
schwann cell
maintains myelin sheath around a peripheral neuron
myelin sheath
layered fatty covering that insulates axon
node of ranvier
axon exposed between schwann cells (no myelin)
helps impulse travel faster!
axon terminal
ending of axon where it meets another cell
synaptic bulb
tip of the axon terminal
Polarity of neurons. Which are which?
Multipolar- motor & interneurons
Bipolar & unipolar- sensory
Characteristics of bipolar
One dendrite
One axon
Located: retina, inner ear, olfactory, brain areas
Characteristics of unipolar
Dendrites & axon fused into 1 process (cell body not direct line of axon and dendrite)
Located: most sensory neurons
Characteristics of multipolar
Several dendrites
One axon
Located: brain and spinal cord
