Human AP Final Exam Review CH. 11

Main Function of Nervous System

Controls thoughts, actions, and emotions with fast signals

3 Functions of Nervous System

• Sensory input

• Integration

• Motor output

Central Nervous System (CNS)

Brain and spinal cord.

Peripheral Nervous System (PNS)

Spinal nerves, cranial nerves, and ganglia.

Sensory (Afferent) Division

Carries info to CNS.

Motor (Efferent) Division

Carries info from CNS to muscles/glands.

Somatic Motor Division

Controls skeletal muscles (voluntary).

Autonomic Nervous System (ANS)

Controls smooth/cardiac muscle and glands (involuntary).

Sympathetic

Fight or Flight

Parasympathetic

Rest and Digest

Neuroglia (Glial Cells)

Support neurons.

CNS Glial Cells

Astrocytes, microglia, ependymal, oligodendrocytes.

PNS Glial Cells

Schwann cells, satellite cells.

Neuron Parts

• Soma (cell body)

• Dendrites = receive signals

• Axon = sends signals

Axon Hillock

Where the signal starts.

Axon Terminals

End of axon, release neurotransmitters.

Anterograde Transport

Moves materials from soma to axon.

Retrograde Transport

Moves materials from axon to soma.

Myelin

Fatty layer that speeds up signals.

Myelin Makers

• CNS: Oligodendrocytes

• PNS: Schwann cells

Multipolar

many dendrites, one axon

Bipolar:

one dendrite, one axon

Unipolar:

one branch splits into two

Neuron Types by Function

• Sensory: to CNS

• Interneurons: within CNS

• Motor: from CNS to body

Bundle of axons wrapped in layers:

• Endoneurium

• Perineurium

• Epineurium

Resting Membrane Potential

Neuron at rest is charged, ready to fire.

Ion Channels Leak:

always open

Ion Channels Gated:

open by signal (chemical, voltage, or pressure)

How Neurons Create Signals

By moving sodium (Na⁺) and potassium (K⁺) ions across the membrane.