Foundations of Biopsychology: Cells of the Nervous System Flashcards
The nervous system is made up of two types of cells
neurons and glia
specialized to carry out the functions of information processing and communication.
Neuron
Cells in the nervous system that support the activities of neurons.
Glia
A small structure within a cell that carries out a specific function.
organelle
The main mass of a neuron, containing the nucleus and many organelles.
cell body / soma
The branch of a neuron usually responsible for carrying signals to other neurons.
axon
The branch of a neuron that generally receives information from other neurons.
dendrite
The primary task of any _____ is to form a boundary between the cell and its external environment.
cell membrane
The ______ must separate the ______ of the cell’s interior from the _______ surrounding the neuron.
neural membrane, intracellular fluid, extracellular fluid
Because they are fats, ______ do not dissolve in water. (oil and water do not mix).
phospholipids
Neural membranes consist of _______.
Neural membranes consist of double layers of phospholipid molecules.
Embedded within the ______ are proteins that serve as ion channels and ion pumps.
lipid layers
A protein structure embedded in a cell membrane that allows ions to pass without the use of additional energy.
ion channel
A protein structure embedded in a cell membrane that uses energy to move ions across the membrane.
ion pump
Ion channels have the ability to _____ in response to stimuli in their immediate vicinity.
open and close
Some ion channels, known as _______, open and close in response to the electrical status of adjacent areas of membrane.
voltage-dependent channels
An ion channel in the neural membrane that responds to chemical messengers.
ligand-gated channel
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.
sodium-potassium pump
A protein structure embedded in the neural membrane that uses energy to move calcium ions out of the cell.
calcium pump
Sodium-potassium and calcium pumps help ________ in chemical composition between the intracellular and extracellular fluids.
maintain the differences
The structural support that maintains the shape of the neuron is provided by the ________.
cytoskeleton
3 types of cytoskeleton
microtubule
Neurofilaments
microfilament
The largest fiber in the cell cytoskeleton, responsible for the transport of neurotransmitters and other products to and from the cell body.
microtubule
run parallel to the length of the axon and provide structural support.
Neurofilaments
The smallest fiber found in the cell cytoskeleton that may participate in the changing of the length and shape of axons and dendrites.
microfilament
The substructure within a cell body that contains the cell’s DNA.
nucleus
An organelle in the cell body involved with protein synthesis.
ribosome
An organelle in the cell body that participates in protein synthesis.
endoplasmic reticulum
An organelle in the cell body that packages proteins in vesicles.
Golgi apparatus
Organelles that provide energy to the cell
mitochondria
produce and assemble the cell’s ribosomes
nucleolus
specialized for the generation of action potentials.
axon hillock
The fatty insulating material covering some axons that boosts the speed and efficiency of electrical signaling.
Myelin
The uncovered section of axon membrane between two adjacent segments of myelin.
node of Ranvier
One of the branches near the end of the axon closest to its targets.
collateral
The swelling at the tip of an axon collateral specialized for the release of neurotransmitter substances.
axon terminal
A neuron with one branch that extends a short distance from the cell body then splits into two branches.
unipolar neuron
A neuron with two branches: one axon and one dendrite.
bipolar neuron
A neuron that has multiple branches, usually one axon and numerous dendrites.
multipolar neuron
Types of neurons
astrocyte
oligodendrocyte
schwann cell
microglia
the cells in the nervous system that support the activities of neurons, are generally categorized by size.
glia
the largest varieties of glial cells
macroglia
smaller varieties of glial cells
microglia
characterized by large concentrations of sodium and chloride ions and a relatively small concentration of potassium (K+) ions.
Extracellular fluid
The measurement of the electrical charge across the neural membrane when the cell is not processing information.
resting potential
The force that moves molecules from areas of high concentration to areas of low concentration. (also through electrical force)
diffusion
Depolarization of _____ (threshold for action potential)
-65mV
2 types of synapse
chemical synapse, electrical synapse
A type of synapse in which messages are transmitted from one neuron to another by chemical neurotransmitters.
chemical synapse
A type of synapse in which a neuron directly affects an adjacent neuron through the movement of ions from one cell to the other.
electrical synapse
electrical synapse width of synaptic gap
3.5 nm
chemical synapse width of synaptic gap
20 nm
The process in which vesicles fuse with the membrane of the axon terminal and release neurotransmitter molecules into the synaptic gap.
exocytosis
A special protein structure embedded in neural membrane that responds to chemical messengers.
receptor site
Methods for Deactivating Neurotransmitters
a)diffusion away from the synapse,
b)through the action of special enzymes, or
c)through reuptake.
neurotransmitter diffuses away from areas of high concentration to areas of low concentration.
Diffusion
neurotransmitter molecules are deactivated in the synapse by enzymes in the synaptic gap.
Deactivating Enzymes
the presynaptic membrane uses its own set of receptors known as ______
transporters
the presynaptic membrane uses its own set of receptors known as transporters to recapture molecules of neurotransmitter substance and return them to the interior of the axon terminal.
Reuptake
