1. DO NOW
The body is organized with different levels, the smallest are called cells. Name the next three
Tissues, organs , organ systems
Name two functions of the nervous system.

2. Neuron
Cells that transmit messages carried by the nervous system.

3. Neuron Nucleus Axon terminals Cell body Myelin sheath Axon Nodes
Dendrites

4. Impulse

5. Nerve Impulse
Resting Neuron: outside of cell has net positive charge inside has net negative charge.
Where does this difference come from?

6. The Cell membrane has a Na+ / K+ pump
The Cell membrane has a Na+ / K+ pump. This pump maintains the Resting Potential
Sodium/potassium pump sits on the membrane of the neuron and uses energy to pump Na+ out of the cell and K+ into the cell.

7. Figure 35-6 Resting Potential
Section 35-2

8. Moving Impulse
Once a stimulus is received it causes a movement of ions across the membrane – the Nerve Impulse

9. Figure 35-7 An Impulse
Section 35-2

10. Figure 35-7 An Impulse
Section 35-2

11. Figure 35-7 An Impulse
Section 35-2

12. Figure 35-7 An Impulse
Section 35-2

13. action potential

14. Cell Membrane of Neuron
Contains thousands of protein channels letting the ions through.
Changing the charge of the inside of the neuron from negative to positive is called the action potential.

15. Review
Define
Neuron
Nerve Impulse
Cell Membrane of Neuron

16. Nerve impulses are ALL or NOTHING
Threshold a minimum level that the nerve need to transmit an impulse.

17. Synapse
The location where Axon Terminals of a nerve cell can transfer the nerve impulse to the dendrites of another cell.

18. Dendrite of adjacent neuron
Figure 35-8 The Synapse
Section 35-2
Direction of Impulse
Dendrite of adjacent neuron
Axon
Receptor
Vesicle
Axon terminal
Synaptic cleft
Neurotransmitter

19. Neurotransmitters
Chemicals used by a neuron to transmit an impulse from one nerve to another

20. resting potential

21. Central Nervous System
The CNS consists of the Brain and the Spinal cord

22. BRAIN – mass 1.4 kg/ 100billion neurons
Cerebrum – responsible for the voluntary or conscious activities of the body
Contains folds and grooves has four lobes – frontal, temporal, parietal, occipital
Outer layer is called cerebral cortex and is made of gray matter-cell bodies
Inner layer is white matter – axons and myelin sheaths.

23. Cerebrum, cerebellum, brain stem
Section 35-3
Cerebrum, cerebellum, brain stem
Pons
Pituitary gland
Hypothalamus
Cerebrum
Medulla oblongata
Spinal cord
Cerebellum
Pineal gland
Thalamus

24. Brain - Cerebellum
Second largest region of the brain, coordinates and balances the actions of the muscles so that the body can move without falling and efficiently,

25. Brain – The Brain Stem
Connects brain and spinal cord. Has two regions the pons and the medulla oblongata. Blood pressure, heart rate, breathing, and swallowing are controlled here.

26. Brain – thalamus and hypothalamus
Thalamus – receives messages from all sensory organs and relays it to the cerebrum.
Hypothalamus – control center for recognition of hunger, thirst, fatigue, anger, and body temp.

27. human brain cross section

28. Spinal Cord Humans have 31 pairs of spinal nerves
Some nerve impulses are processed in the spinal cord – reflex
Reflex- quick automatic response to a stimulus- allowing you to respond to danger immediately.

29. Spinal cord Spinal nerve Central canal Gray matter White matter
Meninges

30. Peripheral Nervous System
Consists of all nerves and cells that aren’t part of the CNS including the cranial nerves.
Divided into sensory division and motor division.

31. Senses
Visual System – we are able to see because light enters the eye through the cornea, the image is focused with the lens and travels across vitreous humor fluid to rest upon the rods and cones of the retnia

32. Photoreceptors Rods are responsible for light sensitivity –
Cones are able to differentiate colors.

33. Cow Eye Dissection

34. Hearing and Balance

35. Hearing
We hear because mechanical energy - from vibrations are converted into neuronal messages through the cochlear nerve.

36. Balance
The Ear contains structures that help the body maintain balance – called the semicircular canals.

37. Smell and taste
The nasal cavity contains chemoreceptors to detect chemical
Sense of taste is often confused with sense of smell
Taste is also a chemical sense, taste buds detect chemical changes- salty, bitter, sweet and sour.

38. Touch
The amount of sensory receptors on the skin varies with fingers, toes and face.

39. DRUGS - that effect the synapse
Stimulants – increases the actions regulated by the nervous system, blood pressure, breathing rate,
Depressants – decrease heart rate, breathing rate, lower blood pressure, relax muscles
Opiates – mimic endorphins – naturally occurring brain chemicals to lessen pain.

40. drugs
Marijuana – bad for the lungs, long term use can lead to memory loss, decreased ability to concentrate, and infertility in males.
Alcohol – a depressant that slows down the rate the CNS functions-
alcoholism and destruction of liver