NERVOUS SYSTEM
ROLE → CNS = central nervous system
• receives, transmits and integrates internal
and external information based on which
it develops appropriate answers
• controls the body’s actions and sensations
• coordinates thinking, emotions, memory
SYSTEMS
• Central Nervous System (CNS)
- Structure: Brain & Spinal Cord
• Peripheral Nervous System (PNS)
- Structure: Nerves
the NEURON
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, STRUCTURE
➢ Cell Body
- cell membrane + cytoplasm
Forms the gray substance of the NS in which the nerve cells are located
➢ Neural Extensions
- dendrite + axon (it ends with the terminal buttons)
forms the white substance of the NS in which the nerve impulse
conduction
pathways are located
PROPERTIES
A. Excitability
The property of the neuron to respond through
specific manifestations (nerve impulses) DENDRITE
when stimulated
CELL BODY
B. Conductibility
The property of the neuron to conduct nerve AXON
impulses. They are unidirectional due to the synapses
TYPES OF NEURONS
According to the functions they perform, neurons can be:
▪ SENSORY – they take the impulses from
the sense organs and transmit them to
the nervous centers
▪ MOTOR – they transmit commands to
effectors (muscles and glands)
▪ INTERNEURONS – they connect the sensory
neurons to the motor neurons
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