1. Nervous System (Overview)

2. REVIEW: CNS PNS Brain and spinal cord Protected by
Meninges
skull and vertebrae
PNS
All the other neurons
Serves limbs and organs
Sensory and motor branches
Exposed to toxins and more susceptible to injuries

3. Involuntary (e.g. Heartbeat, peristalsis)
Quick Responses (fight or flight)
Slower Responses
(rest & digest)

7. Neuron Dendrites (receives electrical stimulation from other neurons)
Cell Body
Axon terminals (transmits
electrical stimulation to other
neurons)

8. Functional Differences b/w Neurons
Sensory Neurons
E.g. Those in skin
Receive sensory information & transmit the information (as a nerve impulse) to the CNS (brain & spinal cord)
Motor Neurons
Take information from CNS to effectors (e.g. Muscles, glands, other organs)
Interneurons
Link sensory & motor neurons

9. Example: the reflex arc
Sensory neurons are stimulated by the pricking of the rose thorns
signal travels to the spinal cord along sensory neurons
synapse with interneurons within the CNS
Interneurons stimulate motor neurons
travels along their axons to the muscle
Muscle contracts to withdraw the hand

10. Non neural Cells Oligodendrocytes Schwann cells
form the myelin sheaths of axons in CNS
Schwann cells
form a myelin sheath around each axon in PNS

11. Myelin Sheath 80% lipid + 20% protein
Protects the axon and helps speed up the conduction of nerve impulses

12. Homework Make yourself a glossary for the following terms:
Glial Cell, Myelin Sheath, node of Ranvier
Central Nervous System, Peripheral Nervous System
Somatic Nervous System, Autonomic Nervous System, Sympathetic Nervous System, Parasympathetic Nervous System