Nervous system is made up of;
Neurons- a cell of the NS that is specialized for information processing and
Glia- cells in the nervous system that support the activities of neurons (10-50 for 1 N)
Organelle- small structure within a cell that carries out a specific function (membranes
cell body/ soma- the main mass of the neuron containing the nucleus and organelles
Axons- the branch of a neuron responsible for carrying signals to other neurons
Dendrites- the branch of neuron that general receives information from other neurons
- made up of double layer of phospholipids, fatty molecules that contain phosphate
Permeability- the movement of substances across the cell membrane (IC,IP)
Ion channel- protein structure embedded in a cell membrane that allows ions to pass
without the use of additional energy
Ion pump-protein structure embedded in the cell membrane that uses energy to move ions
across the membrane
Ions- electrically charged particle in solution
Intracellular fluid- fluid inside the cell high K+, low Na & Cl
Extracellular fluid- fluid surrounding the cell (divided by the cell membrane) high Cl-
& Na+, low K+
Voltage dependent reactions- open and close in response to electrical status of adjacent
areas of the membrane
Ligand gated channels- open when they come in contact with specific chemicals (natural
Synapse- junction between two neurons where info is transferred
Sodium-potassium pumps- An ion pump that uses energy to transfer three sodium ions to
the extracellular fluid for every two potassium ions retrieved from the extracellular fluid.(
helps maintain the differences in chemical composition between the intracellular and
extracellular fluid) send out 3 Na and collect 2 K ions uses 20-40 of energy
Calcium pump -A protein structure embedded in the neural membrane that uses energy to
move calcium ions out of the cell.
Neurotransmitter- A chemical messenger that transfers information across a synapse.
Cytoskeleton -A network of filaments that provides the internal structure of a neuron.
(inside the membrane)
Microtubule- The largest fiber in the cell cytoskeleton, responsible for the transport of
neurotransmitters and other products to and from the cell body.
Anterograde transport- Movement of materials from the cell body of a neuron to the
axon terminal along the microtubules.
Retrograde transport- Movement of material from the axon terminal back to the cell
body via the cell’s system of microtubules. - Alzheimer’s disease the onset of phosphate being added to tau which unravels the
neurofilament –A neural fiber found in the cell cytoskeleton that is responsible for
structural support. (most common fiber structure similar to a hair)
Microfilament The smallest fiber found in the cell cytoskeleton that may participate in the
changing of the length and shape of axons and dendrites.
The Neural Cell Body
Nucleus-The substructure within a cell body that contains the cell’s DNA.
Nucleolus- A substructure within a cell nucleus where ribosomes are produced.
Ribosome -An organelle in the cell body involved with protein synthesis.
Endoplasmic reticulum-An organelle in the cell body that participates in protein
Golgi apparatus -An organelle in the cell body that packages proteins in vesicles.
Mitochondria-Organelles that provide energy to the cell by transforming (extracting)
pyruvic acid and oxygen into molecules of adenosine triphosphate (ATP).
- location at which information from other neurons is received
Synaptic gap- the tiny fluid- filled space between neurons forming a synapse.
Dendritic spine A knob on the dendrite that provides additional membrane area for the
formation of synapses with other neurons able to change shape based on the amount of
activity occurring at the synapse
-responsible for carrying neural messages to other neurons
- larger diameter for axons are faster then smaller ones
axon hillock The cone-shaped segment of axon located at the junction of the axon and cell
body that is specialized for the generation of action potentials transmitted down the axon
Myelin –The fatty insulating material covering some axons that boosts the speed and
efficiency of electrical signaling. formed by certain types of glia that wrap themselves