week 5 - neurons

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 bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.

dendrite

Part of a neuron that extends away from the cell body and is the main input to the neuron.

diffusion

The force on molecules to move from areas of high concentration to areas of low concentration.

elecetrostatic 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 potneitlas

A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.

inhibitory postsynaptic potential

A hyperpolarizing postsynaptic current that causes the membrane potential to become more negative and move away from the threshold of excitation.

ion channles

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.

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.

neurotransmitters

Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.

nucelus

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 while the cell is at 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.

soma

Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.

synapse

Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.

synaptic gap

Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.

synaptic vesicles

Groups of neurotransmitters packaged together and located within the terminal button.

terminal button

The part of the end of the axon that form synapses with postsynaptic dendrite, axon, or soma.

threshold of excitation

Specific membrane potential that the neuron must reach to initiate an action potential.

adrenal glands

Sits atop our kidneys and secretes hormones involved in the stress response - think of adrenalin

gonads

Secrete hormones related to sexuality, sex, reproduction, and other phenomena, including physical/bodily aspects and behaviour. The gonads are either in the ovaries (usually tied to femaleness, but not always) and testes (usually tied to maleness, but not always).

pancreas

Secretes hormones that regulate blood sugar - secrete glucagon and insulin

pituitary galnd

Secretes a number of key hormones, which regulate fluid levels in the body, and a number of messenger hormones, which direct the activity of other glands in the endocrine system

thyroid gland

Secretes hormones that regulate growth, metabolism, and appetite

agonsists vs antagonists

A drug that increases or enhances a neurotransmitter’s effect.

vs. A drug that blocks a neurotransmitter’s effect.

enzyme inductiin

Process through which a drug can enhance the production of an enzyme.

pharmackinetics

The action of a drug through the body, including absorption, distribution, metabolism, and excretion.

psychotropic drug

A drug that changes mood or emotion, usually used when talking about drugs prescribed for various mental conditions (depression, anxiety, schizophrenia, etc.).

psychoactive drugs

A drug that changes mood or the way someone feels.

psychotropic

A drug that changes mood or emotion, usually used when talking about drugs prescribed for various mental conditions (depression, anxiety, schizophrenia, etc.).

what hormone is best described as the major excitatory neurotransmitter in the brain and has an important impact on learning?

glutamate