1. Functions, Divisions, & Neurons
The Nervous System
Functions, Divisions, & Neurons

2. Functions
Sensory Input
Integration
Motor functions

3. Divisions of Nervous System
Central nervous system (CNS)
Peripheral nervous system (PNS)

4. Central Nervous System
Brain
Spinal cord

5. Peripheral Nervous System
Consists of nerves and ganglia
Further divided:
Afferent division (sensory)
Efferent division (motor)

6. Efferent Division of PNS
Further divided:
Somatic nervous system (voluntary)
Autonomic nervous system (involuntary)

7. Autonomic nervous system
Further divided:
Sympathetic
Parasympathetic

9. Nerve Tissue
Neuron
Neuroglia (glial cell)

10. Neuron

11. Types of Neurons Afferent (sensory) Efferent (motor)
Inter-neurons (association neurons)

12. Neuroglia Do not conduct nerve impulses
Serve as protection and nourishment for neurons

13. Nerve Impulses
Resting membrane
Stimulation of neuron

14. Resting membrane Non-conducting neuron Lots of Na+ outside neuron
Lots of K+ inside neuron, but even more negative ions found inside
Membrane is polarized

16. Stimulation of Neuron
A stimulus changes the membrane to allow passive movement of ions.
Stimulus must be strong enough to make membrane highly permeable (threshold).

17. Action Potential – Nerve Impulse
Depolarization
Reverse polarization
Repolarization

19. Action Potential Animation
Nerve Impulse

20. Conduction of Impulse
Action potential must continue the length of a neuron
Neurotransmitters carry impulse across the synaptic cleft to new neuron

21. Continuous vs Saltatory Action Potentials

22. Reflex Arcs Functional unit of nervous system
Allows for rapid response to stimulus
Components:
Receptor
Sensory neuron
Integration center
Motor neuron
Effector