AnaPhy Chapter 8: Nervous System (Electrical Signals)

Resting membrane potentials and action potentials occur in neurons
True False

2 types of membrane channels

Channels that are always open; Ions can "leak" across the membrane down their concentration gradient

Channels that are generally closed, but can be opened due to voltage or chemical

Channels that can be opened by neurotransmitters

Channels that can be opened by a change in membrane potential

Maintains resting levels of ions across the cell membrane

The sodium-potassium pump actively transports ___ into the cell and ___ out of the cell

The sodium-potassium pump consumes ___ of all the ATP in a typical cell and ___ of the ATP in a neuron

Changes in response to stimuli

Allow conductivity along nerve or muscle membrane, similar to electricity going along an electrical wire

Is generated primarily by the uneven distribution of K+, Na+, and negatively charged proteins across the cell membrane

In neurons, there are ______ more K+ leak channels than Na+ leak channels in the cell membrane

Movement of Na+, called a ____, causes the inside of the cell membrane to become positive, a change called _____.

What constitutes an action potential?

Action potentials are conducted slowly in myelinated axons and more rapidly in unmyelinated axons
True False

Is a junction where the axon of one neuron interacts with another neuron or with cells of an effector organ, such as a muscle or a gland

3 Major components of a synapse

Diffuse across the synaptic cleft and bind to specific receptor molecules on the postsynaptic membrane

Best known neurotransmitters

Enzyme that breaks down the acetylcholine