Neuron Anatomy
What is another name for the cell body of a neuron?
Soma
The Sodium/Potassium Pump uses energy in the form of what?
ATP
Graded potentials are small, localized changes in a neuron's membrane potential that are typically found where?
Graded potentials are small, localized changes in a neuron's membrane potential (typically in the DENDRITES or CELL BODIES).
Chemical messengers can also be called what?
Chemical messengers are called neurotransmitters
Where do we find axoplasm?
Axoplasm is the cytoplasm of the axon, so we find it in the axon.
An axon is a long, slender projection of a nerve cell (neuron) that conducts electrical signals called action potentials - AWAY or TOWARDS - the cell body to other neurons, muscles, or glands?
Axons conduct impulses away from the cell body.
The Sodium-Potassium Pump moves sodium into or out of the cell?
Out of the cell
An action potential is a rapid, temporary rise and fall in the electrical voltage across an axon’s cell membrane, allowing neurons to do what?
An action potential allows neurons to TRANSMIT SIGNALS.
Define a synapse.
A synapse is the specialized junction or microscopic gap between two neurons, (or between a neuron and another cell like a muscle or gland), where nerve impulses are transmitted.
Neurons have extra cells around them that are supporting cells. What is the general name given to these special cells?
These support cells are called glial cells.
What is the main function of nissl bodies?
A major function of nissl bodies is they act as the primary site of protein synthesis in the neuron, producing structural proteins, enzymes, and membrane proteins required for everyday cellular maintenance.
Is the inside of the neuron more negative or more positive than the surrounding area outside the neuron?
The charge is more negative inside the neuron than the extracellular space outside of it.
What is a critical threshold?
A critical threshold is a specific limit or cut-off point where crossing it triggers an immediate change, action, or failure state.
Are chemical synapses or electrical synapses more common?
Chemical Synapses are more common
What is the name of the cells that make up the myelin sheath?
Schwann cells
The extensive branching structure of a dendrite allows it to what?
Increased Surface Area: The extensive branching structure of a dendrite allows a single neuron to connect with and listen to thousands of neighboring neurons at once.
What is the necessary ratio of sodium to potassium to keep the cell in homeostasis?
3:2
Which neuron moves impulses quicker, a myelinated or an unmyelinated axon?
A myelinated axon moves impulses quicker be cause it skips from one node of Ranvier to another.
What do we call the space between the presynaptic and postsynaptic membranes?
Synaptic cleft
What do we call the little gaps found in the myelin sheath?
Nodes of Ranvier
Where do you find the axon hillock and what does it do?
Axon Hillock: The cone-shaped region where the axon connects to the cell body (soma) and where electrical signals are summed up before firing.
The lipid bilayer cell membrane, of a neuron, is mostly impermeable to ions, requiring WHAT to control the flow of the sodium and potassium ions?
The lipid bilayer cell membrane is mostly impermeable to ions, requiring SPECIFIC CHANNEL PROTEINS to control the flow of the sodium and potassium ions.
Name the 3 types of nerve fibers.
Type A, Type B, and Type C
What are synaptic vesicles and where are they found?
Synaptic vesicles: Small, membrane-bound sacs inside the axon terminal that store and release neurotransmitters.
Explain the difference between the terms "extracellular" and "intracellular".
Extracellular means the area OUTSIDE of cells.
Intracellular means the area INSIDE a cell.