1. The Nervous system

2. Functions of the Nervous System
1. Sensory input – gathering information
To monitor changes occurring inside and outside the body
Changes = stimuli
2. Integration
To process and interpret sensory input and decide if action is needed

3. Functions of the Nervous System
3. Motor output
A response to integrated stimuli
The response activates muscles or glands

5. Structural Classification of the Nervous System
Central nervous system (CNS)
Brain
Spinal cord
Peripheral nervous system (PNS)
Nerves outside the brain and spinal cord
Spinal nerves
Cranial nerves

6. Central Nervous System

7. Peripheral Nervous System

8. Functional Classification of the Peripheral Nervous System
Motor & Sensory Divisions
Motor division
Two subdivisions
Somatic nervous system = voluntary
Autonomic nervous system = involuntary
Figure 7.1

9. Organization of the Nervous System
Figure 7.2

10. Sympathetic and parasympathetic divisions typically function in opposition to each other

11. Nervous Tissue: Neurons (Nerve Cell)

12. Neuron Anatomy
Electrical to Chemical Signal
Figure 7.4a

13. Nervous Tissue: Support Cells
Schwann cells
Form myelin sheath that protects signal
Figure 7.3e

14. Neuron Anatomy Extensions outside the cell body
Dendrites – conduct impulses toward the cell body
Axons – conduct impulses away from the cell body
Figure 7.4a

15. Signal Pathway: Sensory to Interneuron (spinal cord) to Brain to Motor Neuron

17. Functional Classification of Neurons
Sensory (afferent) neurons
Carry impulses from the sensory receptors
Cutaneous (Skin) sense organs, for example
Motor (efferent) neurons
Carry impulses from the central nervous system to the muscles, for example

18. Functional Classification of Neurons
Interneurons (association neurons)
Found in neural pathways in the central nervous system
Connect sensory and motor neurons

19. Neuron Classification
Figure 7.6

20. Axons and Nerve Impulses
Axons end in axonal terminals
Axonal terminals contain vesicles with neurotransmitters
Axonal terminals are separated from the next neuron by a gap
Synapse – junction/space between nerves

21. How Neurons Communicate at Synapses
Figure 7.10

22. Parts & Functions of the Human Brain
Check out 3-D Brain Anatomy for more parts & more functions!
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23. 3 Major Parts of The Brain

24. Frontal Lobe Found under your forehead.
Center of reasoning, planning, some parts of speech, movement (motor cortex), emotions, and problem solving.
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25. Phineas Gage

26. Parietal Lobe Found on the top of your head.
Receives sensory input from the skin. (touch, pressure, temperature, & pain)

27. Temporal Lobe Found on the sides of your head above your ears.
Functions include speech perception, hearing, some types of memory (Broca’s Area)
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28. Occipital Lobe Found at the back of your head.
Receives input from the eyes
Often referred to as the visual cortex
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29. Cerebellum Found at the at the back of your head under the cerebrum.
Means “little brain”
Responsible for movement, balance, posture.
Often takes over learned activities-
Like riding a bike!

30. Brainstem Most basic part of your brain.
Controls functions essential to life (breathing, digesting, eliminating waste, sleeping, maintaining body temperature…)
Maintains life without “thinking”
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31. Three parts of Brain Stem:
1. medulla oblonga: innate relfexes, eg. vomiting, coughing, sneezing, heart rate, breathing rate, blood pressure 2. pons: reflexes 3. mid brain: visual

32. Corpus Callosum
This is located centrally between the left and right hemispheres of your brain.
It is a bundle of fibers that connects the left and right hemispheres.
It is believed this area is involved in creativity and problem solving.
Click here to find out more about split brains!

33. Hypothalamus
The hormones produced by this area of the brain govern body temperature, thirst, hunger, sleep, circadian rhythm, moods, and the release of other hormones in the body.