Biology Nervous System Module 7

Nerves

Bundles of neuron axons and their coverings, which are found outside the CNS

Ganglia

Collections of neuron cell bodies that are found outside the CNS

Spinal nerves

Nerves that originate from the spinal cord

Cranial nerves

Nerves that originate from the brain

Afferent neurons

Beaton that transmit action potential from the sensory organs to the CNS

Efferent Neurons

Neurons that transmit action potentials from CNS to the effector organs

Somatic Motor nervous system

PNS neurons that transmit action potentials from the CNS to skeletal muscles

Automatic nervous system

PNS neurons that transmit action potentials from the CNS to smooth muscles, cardiac muscles, and glands

Sympathetic division

Division of the ANS that generally prepares the body for increased energy expenditure

Parasympathetic division

Division of the ANS that regulates resting and nutrition related functions such as digestion, defecation, and urination

Axon

The part of the neuron process that carries signals away from the cell body

Resting Potential

The inside of the neuron is negative

Higher Na+ outside and higher K+ inside

Sensory Nerves

Can only send incoming messages from the CNS to muscles or glands

Motor (efferent) Nerves

Can only send outgoing messages from the CNS to muscles or glands

Astrocytes, Microglia, Ependymal cells, OligodendrocytesI

In the CNS

Astrocytes

Neuralgia that form the blood brain barrier

Microglia

Neuroglia that engages in phagocytosis to fight infections in the brain.

Ependymal cells (ciliated) CNS

Moves cerebrospinal fluid

Ependymal cells (non-ciliated) CNS

Secretes cerebrospinal fluid

Oligodendrocytes

Binds together and insulates CNS neurons

Schwann cells

The only PNS cells, insulates PNS neurons