Chapter 3.1 - 3.2 Flashcards
Neurons
Is an electrically excitable cell that processes and transmits information through electrical and chemical signals.
Gila
Support the neurons in many ways such as by insulating them, synchronizing activity among neighboring neurons, and removing waste products (small but more numerous than neurons)
Cell body
Contains the nucleus of the cell. The compact area of a nerve cell that constitutes the nucleus and surrounding cytoplasm, excluding the axons and dendrites.
Dendrites
Are widely branching structures that receive input from other neurons.
Axon
Is a single, long, thin, straight fiber with branches near its tip. The appendage of the neuron that transmits impulses away from the cell body.
Myelin
An insulating sheath that speeds up the transmission of impulses along an axon
Action potential
An excitation that travels along an axon at a constant strength, no matter how far it travels. (is a yes-no or on-off message, like flicking a light switch. This principle is known as the all-or-none law) The change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated, serving to transmit nerve signals.
Resting potential
An electrical polarization across the membrane (or covering) of an axon. - the imbalance of electrical charge that exists between the interior of electrically excitable nerve cells and their surroundings. The resting potential of electrically excitable cells lies in the range of 60 to 95 millivolts (1 millivolt = 0.001 volt), with the inside of the cell negatively charged. If the inside of a cell becomes more electronegative (i.e., if the potential is made greater than the resting potential), the membrane or the cell is said to be hyperpolarized. If the inside of the cell becomes less negative (i.e., the potential decreases below the resting potential), the process is called depolarization.
Snyapse
The specialized junction between one neuron and another, a neuron releases a chemical that either excites or inhibits the next neuron. a region where nerve impulses are transmitted and received, encompassing the axon terminal of a neuron that releases neurotransmitters in response to an impulse, an extremely small gap across which the neurotransmitters travel, and the adjacent membrane of an axon, dendrite, or muscle or gland cell with the appropriate receptor molecules for picking up the neurotransmitters.
Neurotransmitter
A chemical that activates receptors on other neurons. - any of several chemical substances, as epinephrine or acetylcholine, that transmit nerve impulses across a synapse to a postsynaptic element, as another nerve, muscle, or gland.
Postsynaptic neuron
The neuron on the receiving end of the neuron.
Terminal button
A typical axon has several branches, each ending with a little bulge called a Terminal button or (presynaptic ending) Tiny bulblike structures at the end of the dendrites, which contain neurotransmitters that carry the neuron’s message into the synapse
Dopamine
A neurotransmitter, in the central nervous system, retina, and sympathetic ganglia, acting within the brain to help regulate movement and emotion also memory and cognition : its depletion may cause Parkinson’s disease.
Parkinson’s Disease
A condition that affects about 1% of people over the age of 50. Main symptoms are difficulty in initiating voluntary movement, slow movement, tremors, rigidity, and depressed mood.
Psychoactive drugs
Alter experience by altering activity at synapses.
