Week 5: Neurons Flashcards
Neurons, Hormones and Behaviour, Psychopharmacology
Dendrites
Part of a neuron that extends away from the cell body and is the main input to the neuron.
Soma
Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
Axon
Collection of nerve cells found in the brain which typically serve a specific function.
Synapse
Collection of nerve cells found in the brain which typically serve a specific function.
Myelin Sheath
Substance around the axon of a neuron that serves as insulation to allow the action potential to conduct rapidly toward the terminal buttons.
Terminal Button
The part of the end of the axon that form synapses with postsynaptic dendrite, axon, or soma.
Spines
Protrusions on the dendrite of a neuron that form synapses with terminal buttons of the presynaptic axon.
Synaptic Gap
Protrusions on the dendrite of a neuron that form synapses with terminal buttons of the presynaptic axon.
Synaptic Vesicles
Groups of neurotransmitters packaged together and located within the terminal button.
Neurotransmitters
Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Types of Neurons - Cells in the Brain
SENSORY - neurons that help us receive information about the world around us
MOTOR - neurons that allow us to initiate movement and behavior, ultimately allowing us to interact with the world around us.
INTERNEURONS - process the sensory input from our environment into meaningful representations, plan the appropriate behavioral response, and connect to the motor neurons to execute these behavioral plans.
Three main categories of neurons:
UNIPOLAR - structured in such a way that is ideal for relaying information forward, so they have one neurite (axon) and no dendrites. They are involved in transmission of physiological information from the body’s periphery such as communicating body temperature through the spinal cord up to the brain.
BIPOLAR - involved in sensory perception such as perception of light in the retina of the eye. They have one axon and one dendrite which help acquire and pass sensory information to various centers in the brain.
MULTIPOLAR - most common and they communicate sensory and motor information in the brain. For example, their firing causes muscles in the body to contract. Multipolar neurons have one axon and many dendrites which allows them to communicate with other neurons.
GLIA - While glial cells play a vital role in neuronal support, they do not participate in the communication between cells in the same fashion as neurons do.
Cell Membrane
A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.
ION Channels
Proteins that span the cell membrane, forming channels that specific ions can flow through between the intracellular and extracellular space.
Diffusion
The force on molecules to move from areas of high concentration to areas of low concentration.
Electrostatic Pressure
The force on two ions with similar charge to repel each other; the force of two ions with opposite charge to attract to one another.
Resting Membrane Potential
The voltage inside the cell relative to the voltage outside the cell while the cell is a rest (approximately -70 mV).
Sodium-Potassium Pump
An ion channel that uses the neuron’s energy (adenosine triphosphate, ATP) to pump three Na+ ions outside the cell in exchange for bringing two K+ ions inside the cell.
