Week 5 Flashcards
(49 cards)
Action potential
A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation
Axon
Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron
Cell membrane
A lipid bilayer of molecules that separates the cell from the surrounding extracellular fluid
Dendrite
Part of a neuron that extends away from the cell body that is the main input to the neuron
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
Excitatory postsynaptic potentials
A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold if excitation
Inhibitory postsynaptic potentials
A hyperpolarizing current that causes the membrane potential to become more negative and move away from the threshold of excitation
Ion channels
Proteins that span the cell membrane, forming channels that specific ions can flow through between the intracellular and extracellular space
Ionotropic receptor
Ion channel that opens to allow ions to permeate the cell membrane under specific conditions, such as the presence of a neurotransmitter or a specific membrane potential
Myeline sheath
Substance around the axon of a neuron that serves as insulation to allow the action potential to conduct rapidly toward the terminal buttons
Neurotransmitters
Chemical substance released by presynaptic terminal button that acts on the postsynaptic cell
Nucleus
Collection of nerve cells found in the brain which typically serve a specific function
Resting membrane potential
The voltage inside the cell relative to the voltage outside the cell which the cell is at rest (approx. -70mV)
Sodium-potassium pump
An ion channel that uses the neuron’s energy (ATP) to pump three NA+ ions outside the cell in exchange for bringing two K+ ions inside the cell
Soma
Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis
Spines
Protrusions on the dendrite of a neuron that forms synapses with terminal buttons of the presynaptic axon
Synapse
Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic dendritic spine, axon, or soma
Threshold of excitation
Specific membrane potential that the neuron must reach to initiate an action potential
5a-reductase
An enzyme required to convert testosterone to 5a-dihydrotestosterone
Aggression
A form of social interaction that includes threat, attack, and fighting
Aromatase
An enzyme that converts androgens into estrogens
Chromosomal sex
The sex of an individual as determined by the sex chromosomes
Defeminization
The removal of the potential for female traits
