Chapter 12 Practice Quiz Flashcards
If a sodium channel in the plasma membrane of a neuron open, the [Na+] will move
inside the cell
Impulses that are going toward the CNS are called __________ and impulses going away from the CNS are called __________.
Afferent, efferent
__________ is the term used to describe the movement of potassium ions to the outside of a neuron, and __________ is the term used to describe excess potassium ions moving to the outside of a neuron.
Repolarization, hyperpolarization
The smooth muscles and glands are controlled by the __________________________ nervous system.
.
autonomic nervous system
During repolarization, the sodium channels are closed and inactivated. How does this affect a neuron?
The neuron cannot respond to new stimuli
The all-or-none principle states that
all stimuli great enough to bring the membrane potential to threshold will produce identical action potential
The myelin sheath that covers many Central nervous system axons is formed by
oligodendrocytes
Mechanically –gated ion channels are a class of transmembrane ion channels which open their pores in response to mechanical deformation of a neuron’s plasma membrane.
True
When the sodium potassium pump breaks down a molecule of ATP, ______ K+ ions are moved into the cell and ______ Na+ are moved out of the cell.
2/3
voltage-gated potassium channels are open and potassium leaves the cell making cell more negative inside.
The junction between two communicating neurons is called the
synapse
The skeletal muscles are controlled by the _______________________________nervous system
somatic motor nervous system
The 2 divisions of the somatic nervous system are the sympathetic division and the parasympathetic division.
False
An example of an effector
Skeletal Muscle
Smooth muscle
Glands
Extracellular potassium levels are ____________________ intracellular potassium levels
lower than