Nervous System: Structure, Function, and Neurotransmitters Overview chapter 12

What is the primary function of the nervous system?

It is the master controlling and communicating system of the body.

What are the two main components of the nervous system?

Neurons and Neuroglia.

What are the two main divisions of the nervous system?

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What does the Central Nervous System (CNS) consist of?

The brain and spinal cord.

What are tracts in the CNS?

Collections of neuron axons.

What are ganglia in the PNS?

Collections of neuron cell bodies.

What type of impulses do ascending tracts carry?

Sensory impulses from the PNS to the spinal cord and brain.

What type of impulses do descending tracts carry?

Motor impulses from the CNS to the PNS.

What are afferent neurons responsible for?

Carrying sensory information towards the brain.

What are efferent neurons responsible for?

Carrying motor commands away from the brain.

What are the three main functions of the nervous system?

Sensory input, integration, and motor output.

What is the role of neuroglia?

To support, segregate, and insulate neurons, and promote their health and growth.

What is the function of astrocytes in the CNS?

They form the blood-brain barrier and control K+ levels.

What is the role of oligodendrocytes?

To produce the myelin sheath around axons in the CNS.

What is the function of Schwann cells in the PNS?

To produce the myelin sheath around PNS axons and assist in regeneration of nerve fibers.

What is the neurilemma?

The outermost thicker coil of the myelin sheath containing the cytoplasm and nucleus of Schwann cells.

What are the three types of neurons?

Multipolar, bipolar, and unipolar.

What is an action potential?

A rapid rise and fall in membrane potential that occurs when a neuron fires.

What occurs during depolarization?

Na+ ions enter the cell, making the inside more positive.

What occurs during repolarization?

K+ ions exit the cell, restoring the negative membrane potential.

What is saltatory conduction?

The process of action potentials jumping from one node of Ranvier to another along myelinated axons.

What is the synaptic cleft?

The space between the presynaptic and postsynaptic neurons where neurotransmitters are released.

What are excitatory postsynaptic potentials (EPSPs)?

Changes in membrane potential that make it more likely for a neuron to fire an action potential.

What are inhibitory postsynaptic potentials (IPSPs)?

Changes in membrane potential that make it less likely for a neuron to fire an action potential.

What neurotransmitter is released at the neuromuscular junction?

Acetylcholine.

What is the role of glutamate in the CNS?

It acts as an excitatory neurotransmitter causing depolarizations.

What is the function of GABA in the CNS?

It acts as an inhibitory neurotransmitter causing hyperpolarizations.

What neurotransmitter is associated with mood regulation and sleep?

Serotonin.

What are endorphins and enkephalins?

Neuropeptides that act as natural painkillers and can affect the function of neurotransmitters.