Cells of the Nervous System Flashcards
Central Nervous System (CNS)
- comprised of the brain and spinal cord
- All encased with bone- all protected with bone like a helmet
- These are so well protected because if you damage the brain or spinal cord they won’t grow back
(no regrowth possible if you sever a nerve, could get brain plasticity. Where other areas of the brain take over and do the function) - encased within the skull and spinal column.
Peripheral Nervous System (PNS)
- comprised of nerve tissue located outside of the brain and spinal cord.
- Regrowth can happen in this system(nerves can grow back if they are severed)
Soma
the cell body of a neuron which contains the nucleus (contains the DNA which controls the function of the neuron,nucleolous)
Dendrite
A branched treelike structure attached to the soma of a neuron; receives information from the terminal button of other neurons.(way they get info from other neurons tissue, sensory connections)
Axon hillock
Site of summation for incoming information(info in forms of changes in electrical charge, if enough excitation happens then an action potential is propaganded)
Axon
The long, thin cylindrical structure that conveys information from the soma of a neuron to its terminal button
Terminal button
The bud at the end of a branch of an axon; forms synapses with another neuron; sends information to that neuron.(allow connections with neighboring neurons and send info to that neuron)
Synapse
A junction between the terminal button of an axon and the membrane of another neuron.
What is the basic structure of a neuron?
soma dendrite axon hillock axon terminal button synapse
What are the basic components of a neuron?
Input, integration(axon hillock), conduction, output (may release neurotransmitters or flex muscle or connect to blood vessels and capillaries)
Terminal Buttons
end point of axons – transform electrical signal from the axon into a chemical signal sent across the synaptic cleft.
Neurotransmitter
A chemical that is released by a terminal button; has an excitatory or inhibitory effect on another neuron
Bipolar neurons
a neuron with one axon and one dendrite attached to its soma(sensory)
Multipolar neurons
A neuron with one axon and many dendrites. Most common in CNS.
Unipolar neurons
A neuron with one axon attached to its soma; the axon divides, with one branch receiving sensory information and the other sending the information into the central nervous system.
Somatosensory (touch, pain)
How can neurons be classified?
shape: bipolar,multipolar and unipolar
size- large and small
function
Describe Classification of Neuron by size
Large- pyramidal
Small- granular
Sensory neuron
transmits sensory information to the central nervous system.(press on your skin and a signal is sent to you brain that your being touched)
Motor neuron
controls the contraction of a muscle or the secretion of a gland.
if your being touched and you don’t like your being touched you can move your arm away)
Interneuron
located entirely within the central nervous system.
Connecting everything, allow for the free flow of info from one neuron to the next
Can connect a sensory and motor neuron
i
- in your ear you have a cochlea which is filled with liquid and little cilia which vibrate depending on the noise your hearing and those get sent to a neuron in the brain
Action potential
electrical signal down the axon
Membrane
A structure consisting primarily of lipid (fat-like) molecules that makes up the outer boundary of a cell.
Cytoplasm
The viscous, semi-liquid substance inside the cell- Goop
Nucleus
Contains all of the genetic material that the neuron needs to function (chromosomes).
Mitochondria
Double membrane. Contain their own DNA and replicate independently of cells. Converts nutrients into ATP.