Neurons, synapses and signaling Flashcards
Describe neuron structure
Most have branched dendrites that receive signals from other cells, and an axon that transmits signals to other cells.
What is a synapse?
A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter
What are glia and what do they do?
the connective tissue of the nervous system, consisting of several different types of cell associated with neurons that insulate, nourish and regulate the neuron.
What is a central nervous system? What is a peripheral nervous system? What three stages do they process information in?
central: the complex of nerve tissues that controls the activities of the body. In vertebrates it comprises the brain and spinal cord
peripheral: the nervous system outside the brain and spinal cord.
sensory input>integration>motor output to effector cells.
What is an effector cell?
The muscle, gland or organ cell capable of responding to a stimulus at the terminal end of an efferent nerve fiber
What is membrane potential?
The difference in electric potential between the interior and the exterior of a biological cell. Sodium ion concentration is higher outside, potassium ion concentration is higher inside.
In resting neurons, the plasma membranes has many open ____ channels but few open _____ channels
Potassium, sodium
What is resting potential and how is it generated?
When the inside is more negative than the outside. Its generated when ions (principally potassium), diffuses through channels.
Neurons have ______ that open or close in response to stimuli, leading to changes in the membrane potential.
gated ion channels
An increase in the magnitude of membrane potential is called _______
hyperpolarization
What is depolarization?
A decrease in the magnitude of membrane potential.
What is a graded potential?
Changes in membrane potential that vary continuously with the strength of the stimulus.
