Task 2 Flashcards
What are all cells of the neurons system comprised of?
Neurons
In what to parts can the nervous system be divided in?
Central nervous system
Peripheral nervous system
What does the clnervous system serve as?
The manager of the body because it control the functions of every other system
What are the two types of cells on the nervous system?
Neurons and glial cells
What are neurons specialized for?
Reception conduction and transmission of electrochemical signals in the body
What is each neuron?
A self contained functioning unit
How does a neuron work?(in plain terms)
It receives input from other cells integrates those inputs and then distributes the processed information to other neurons
Why does the nervous system use neurons?
In order to generate and relay electrical messages called action potentials to control bodily functions
How does a neuron communicate?
Via electrical impulses or using specific chemicals such as neurotransmitters
What are the principal components of neurons?
Dendrites, soma , axon and the axon terminal
What are the dendrites?
Root like part of the cell that stretches out from the body
What is the input zone ?
Zone that receives electrical and chemical messages from other neurons by grabbing on to neurotransmitters the greater the surface of a dendrite the more information it will receive
What are the two types of messages?
Inhibitory-cell body will not transmit the message to axon
Excitatory-cell body will send the message down the axon and pass it to other neurons
What happened when the messages transmitted towards the soma are large enough?
They will generate an action potential meaning that the signal will be transmitted down the axon
What is the soma?
Ball like structure metabolic center of the neuron
What is the integration zone?
Zone that combines the information the neuron has received to determine whether or not to send a signal of its own.
What is the soma covers by?
A semipermeable membrane that encloses the neuron(cell membrane)
What does the soma contain?
The control center of the neuron which regulates cell functions (nucleus)
What do the cell body and nucleus control ?
The functions over the nerve cell
Where do neither soma nor nucleus play an active role?
In the transmission of a neural signal
What is the cell body responsible for?
-Producing the protein that the other parts of the neuron including dendrites axons and synapses need to function properly
Building new dendrites enabling the Neurons to make new connections with other neurons
-Making chemicals (=neurotransmitters) which neurons use as signals
What is the axon hillock?
Cone shaped region at the junction between axon and cell body it controls the firing of the neuron
What happens when the total strength of the signal exceeds the limit of the axon hillock?
The structure will fire signal(action potential) down the axon
What is the neurons integration zone?l(axon hillock)
Gathers and interprets information from all the synapses of the neurons dendrites and soma then it converts the processes information into a code of electrical impulses that carries the neurons message down the axon toward its targets
What is axon polarization?
The overall balance between the positive and negative charges is such that the inside of the axon is electrically negative with respect to the outside
When is the axon polarized?
In its testing start also known as resting potential
What is the axon?
It is the conduction zone carrying information from cell bodies to terminal buttons (one way street)
The larger the diameter of the axon the aster it transmits information
What are some school ns covered with?
The myelin sheath which acts as an insulator. It surrounds the neurons protects the axon and aids in the speed of transmission.
How is the myelin sheath broken up?
By points known as the nodes of ranvier
What are the nodes of ranvier?
The gap insulating sheath in the axon that causes a discontinuity which facilitates the rapid conduction of nerve impulses
What are the axon terminals?
The output zone which communicates the cells activity to other cells as synapses
What are terminal buttons?
Small knobs at the ends of the axon which release chemicals called neurotransmitters into synapses
What are neurotransmitters?
Chemicals contained in the terminal buttons that enable neurons to communicate they fit into receptor cells on the dendrites on the other neurons like a key in a lock
What are neurotransmitters responsible for?
The reuptake of any excessive neurotransmitters released during the process
What is the reuptake?
Process where excess neurotransmitter is sucked
What is a synapse?
Communication sites where neurons pass nerve impulses among themselves
What are the three main categories of neurons?
Multipolar unipolar and bipolar neurons
What are bipolar neurons?
Sensory neurons consisting of one axon and one dendrite that extend from the cell body
Where are bipolar neurons found?
In the PNS
What is the bipolar neurons main function?
Transmitting sensory information to CNS
Where are bipolar neurons found?
Olfactory visual and hearing (sensory function)
What are unipolar neurons?
One axon that extends from the cell body and divided into two or more branches
Where can unipolar neurons be found?
Ganglia and spinal cord
What are multipolar neurons?
Most common of all neuron types 99%
Have many sets of dendrites and one main axon
Where can multipolar neurons be found?
In the CNS
What are multipolar interneurons?
Neurons with a short axon or no axon at all and their function is to receive information from other neurons process it and pass the integrated info on
What are the three functional types of neurons?
Sensory neurons
Motor neurons
Interneurons
What are sensory neurons?
Neurons that detect changes in external or internal environment and send information about it to the CNS mostly unipolar
What are motor neurons?
Get information from other neurons and convey commands to muscles organs and glands
What are interneurons?
They’re neurons with short axon or no axon at all in the CNS they only receive and send output to other neurons
What is the neurosnstomical structure (table in photograph?
Look table
How are clusters of cell bodies known in the CNS how in the PNS?
CNS nuclei
PNS ganglia
How are bundles of nerve fibers (axons) known in the CNS how in the PNS?
CNS tracts
PNS nerves
How is the myelin providing ganglia known in the CNS how in the PNS?
CNS Oligodendrocytes
PNS Schwann cells
Name all the supporting cells
Glial cell
Oligodendrocyte
Schwann cells
Astrocyte
Microglia
What are all cell membranes composed of?
Lipid bilayer (two layers of fat molecules
What is the function of the lipid bilayer what does it have embedded in it?
It’s function is to take care that the intercellular and extracelular space remain separated
It has molecules and proteins embedded in it
What are the two types of proteins embedded to the lipid bilayer?
Channel proteins: Allow certain molecules to pass through
Signal proteins:Transfer signal to the inside of the neuron when particular molecules bind to them on the outside of the membrane
What two types of transport can protein channels and pumps be?
Passive transport: Channel enables ions to flow rapidly through membranes in a downhill direction, so channel action illustrates passive transport or facilitated diffusion
Active transport: pumps are energy transducers in that they convert one form of free energy into another. Thus, pump action is an example of active transport
Membrane potential (active transport)
Transport of a substance from lower to higher concentration of that substance, using energy from the cell through a living cell membrane
What does active transport (membrane potential) allows?
Cells to obtain nutrients that cannot pads through the membrane by other means
What is selective permeability,
Membrane has some control over what can cross it so that only certain molecules either enter or leave the cell.
Each ion works for one type of ion
Differences between intercellular fluid and extra cellular fluid
Intra: fluid contained within the cell A- K+ CL- Na+
Extra: Cl- Na + K+
Explain A-?
It is unable to pass through the membrane of the axon
Explain Ka+?
It is concentrated within the axon but diffusion pushes it out of the cell while electroestática pressure forces the action inside
Two opposing forces balance K+ and remain where they are
Explain CL- ?
It is the greatest concentration outside the axon
Diffusion pushes it inward electrostatic pressure pushes it outwards —> this opposing forces balance
Explain Na+
Greatest concentration outside the axon
Diffusion pushes it inward electrostatic pressure pushes it inside while sodium potassium pump pushes it out of the axon
What is resting potential?
The electrical difference across the membrane of the neuron
