Thẻ ghi nhớ: Motor Neurons (focus on nervous system organization) | Quizlet

Central Nervous System (CNS)

Brain and spinal cord
Integration and command center

Peripheral Nervous System (PNS)

the sensory and motor neurons (found in cranial nerves and spinal nerves) that connect the central nervous system (CNS) to the rest of the body.

cranial nerves

12 pairs of nerves that carry messages to and from the brain

spinal nerves

31 pairs of nerves that carry impulses to and from the spinal cord

motor neurons

neurons that carry outgoing information from the central nervous system to the muscles and glands

somatic motor neuron

Neuron that stimulates contraction of skeletal muscles (voluntary muscles)

Acetylcholine in the PNS

*Stimulates skeletal muscle contraction at neuromuscular junctions.
*Mediates parasympathetic effects in the autonomic nervous system

NE in the PNS

*mediates sympathetic effects in the autonomic nervous system

Autonomic neuron myelination

generally these type of motor neurons have limited myelination and don't send signals as fast

Somatic motor neuron myelination

Generally these types of neurons are heavily myelinated and travel extremely fast

Somatic Motor Neurons Neurotransmitter

ACh - released onto these voluntary muscle targets
Picture A here

Sympathetic Neurons Neurotransmitter

NE - released on these autonomic targets

Parasympathetic Neurons Neurotransmitter

ACh - released onto these autonomic targets

Autonomic targets include

cardiac muscle
smooth muscle - around blood vessels, glands, GI organs, bladder, etc

The PNS has these two divisions

sensory (afferent)
motor (efferent)

The motor division of the PNS has these 2 branches

voluntary (somatic) - skeletal muscles

involuntary (autonomic) - cardiac muscle, smooth muscles and glands

The autonomic nervous system has these 2 branches

sympathetic
parasympathetic