physiology exam 3

Voltage gated sodium channels

• close during depolarization

• are often activated by inhibitory drugs

• contribute to hyperpolarization of the cell

• open at -55mV

Potassium channels during repolarization

• are ligand gated

• are inactivated at +40 mV

• contribute to the excitation of the cell

• are voltage gated

Hyperpolarizing a cell inhibits an action potential.

• true

• false

Glutamate is primarily considered an excitatory neurotransmitter, along with

• glycine

• MSG

• GABA

• serotonin

Graded potentials are summed along the neuronal axon.

• True

• False

Mark the statement that is FALSE.

• Potassium leak channels are present all throughout the neuron.

• Potassium channel activation is hyperpolarizing.

• During an action potential's relative refractory period, no stimulus will initiate further depolarization.

• Multiple sclerosis is characterized by demyelination of neurons.

Nicotinic receptors are

• ionotropic

• excitatory only

• cholinergic

• All the above

Adrenergic receptors correlate with

• epinephrine and norepinephrine

• serotonin and dopamine

• acetylcholine

• glycine and glutamate

Acetylcholine is used in the skeletal system to stimulate muscle contraction. The cholinergic receptor binds to two Ach molecules, allowing for the channel to open and sodium molecules to enter the cell. This channel is also known as

• a ligand gated channel

• a metabotropic receptor

• a G protein coupled receptor

• acetylcholine linked ion channel

Neurons cannot respond to another stimulus when Na channels are either open or inactivated. This describes the ...

• Refractory Period

• Absolute Refractory Period

• Relative Refractory Period

• Action Potential