Ch1
When a membrane is at rest, what attracts potassium ions to the inside of the cell?
An electrical gradient
Water, oxygen, and ____ freely flow across a cell membrane
Carbon dioxide
In what direction does a local neuron transmit information?
Equally well in any direction
2 basic kinds of cells in nervous system
Neurons & Glia
Santiago Ramon y Cajal demonstrated that
Neurons are separate from one another
Dendrites
are branching fibers that get narrower near their ends
Professor Peach is lecturing in her class about glial cells. She will tell her class that glial cells
are not as well studied as neurons but have been shown to perform many important functions in the nervous system
A drug that blocks the sodium gates of a neuron's membrane will ____.
block the action potential
Why is glucose so important to the brain?
glucose is unique and can cross the blood-brain barrier to be used by neurons
Many dendrites contain short outgrowths called spines that
increase the surface area available for synapses
What type of glial cells myelinate axons in the brain and spinal cord?
oligodendrocytes
when the neuron is at rest, ______ is mostly responsible for the movement of potassium ions out of the cell
potassium's concentration gradient
The primary feature of a neuron that prevents the action potential from traveling back from where it just passed is the _______.
refractory period
A drug will prevent an action potential if it blocks the movement of ________ across the membrane
sodium
nodes or ranvier
the gaps in the myelin sheath along the axon