Nervous System Study Notes

These flashcards cover important concepts related to the structure and function of the nervous system, including neuron physiology, synaptic transmission, and the roles of different types of cells within the nervous system.

What mainly performs the integrative functions of the nervous system?

Interneurons

Where is the highest density of voltage-gated ion channels found in a neuron?

In the myelin sheath gaps

What does the cell body of a mature neuron lack?

Centrioles

What type of glial cells fight infections in the CNS?

Microglia

What does post-tetanic potentiation increase the amount of in the axon terminal?

Calcium

What is an IPSP?

A hyperpolarization of the postsynaptic neuron.

Where does saltatory conduction occur?

In myelinated axons (white matter)

What can some neurotransmitters have depending on the type of receptors on the postsynaptic cell?

Either excitatory or inhibitory effects.

What carries information to the CNS?

Sensory neurons.

What are the necessary properties of neurons to perform their roles?

Excitability, secretion, and conductivity.

What is the absolute refractory period?

A period of time when a neuron cannot respond to another stimulus of any strength.

What produces myelin in the CNS?

Oligodendrocytes.

Where can action potentials be produced in myelinated axons?

Only in specialized regions called myelin sheath gaps.

What neurotransmitter is secreted at an adrenergic synapse?

Norepinephrine.

Can a presynaptic neuron cause other neurons in its vicinity to fire?

No, but it can make them more sensitive to stimulation.

What are neuromodulators?

Substances released along with a neurotransmitter that modify the neurotransmitter's effect.

What is the effect of a neurotransmitter dependent on?

The type of receptor present.

What limits the firing frequency of a neuron?

The absolute refractory period.

What characterizes learning in the nervous system?

Modification of the synapses of existing neurons.

Can neurons undergo mitosis to replace those that are lost?

No, although limited replacement occurs through the multiplication and differentiation of stem cells.