1. NERVOUS SYSTEM

2. Nervous System Overview
Role: Maintain homeostasis
Sense changes (____ neurons)
Integrate information (_______)
Respond (______ neurons)
Basic Anatomy
Mass = ____ lbs 3% total body mass
Main Subdivisions
Central Nervous System (CNS)
Peripheral Nervous System (PNS)

4. CELLS OF THE NERVOUS SYSTEM
2 Types of cells found in the N S:
1. NEURONS: nerve cells
2.NEUROGLIA (Glia): specialized connective tissue

5. NEURONS Also called ________ neurons. Also called _______neurons.
Motor neurons
Also called ________ neurons.
Interneurons
Also called _______neurons.
Sensory neurons

6. AXON: is surrounded by segmented wrapping called _______. - It is:
STRUCTURE OF NEURON
AXON: is surrounded by segmented wrapping called _______.
- It is:

7. Axon - long section, transmits impulses
Dendrite - small extensions from the cell body; receive information
Neurofibrils - fibers within the axon

8. Interesting Facts about the Neuron
Longevity – can live and function for a lifetime
Do not divide – fetal neurons lose their ability to undergo mitosis; neural stem cells are an exception
High metabolic rate – require abundant oxygen and glucose
The nerve fibers of newborns are unmyelinated - this causes their responses to stimuli to be course and sometimes involve the whole body.  Try surprising a baby!

9. GLIA Glia or neuroglia: They are special types of supporting cells
- Function: is to:
* Large cells look like stars: astrocytes
* Smaller cells are Microglia
Example: Oligodendrocytes: helps hold fibers together, produce the fatty myelin sheath that envelops nerve fibers in the brain and spinal cord

11. NERVES
Nerve is a group of peripheral nerve fibers (axons) bundled together like the strands of a cable.
Myelin is found on nerves and is white.
Nerves are referred to as _____ matter of the PNS and also the CNS.
Unmyelinated axons and dendrites are called ________. (because of their color)

12. Brain = Gray over White

13. Spinal Cord = White over Gray

14. REFLEX ARC
Nerve impulses are conducted from receptors to effectors over neuron pathways known as ___________
This results in a _______. (a contracted muscle or secretion from a gland)
2 types of reflex arcs:
- two-neuron arcs: spinal cord and motor neuron
- three-neuron arcs: sensory neurons, interneurons and motor neurons

15. Animation http://www.youtube.com/watch?v=Y5nj3ZfeYDQ

16. RECEPTORS Impulse conduction normally starts in the_______.
Found at the beginning of the dendrites of sensory neurons
Location:

18. MS (MULTIPLE Sclerosis) DAMAGE TO MYELIN
Hard lesions replace the destroyed Myelin
As the myelin is lost, nerve conduction is ______
Causing weakness, loss in coordination, visual impairment, speech disturbances
No known cure, occurs most in women ages
impaired

19. Synapse
A microscopic space from the axon ending of one neuron to the dendrite of another neuron.
The nerve impulse stops, chemicals are sent across the gap, the impulse continues alone the dendrites.

20. Neurotransmitters Chemicals by which neurons communicate
Some help us sleep, inhibit pain, make us energetic
Examples
Acetylcholine-
Norepinephrine and Dopamine-
Serotonin-
Endorphins-
Acetylcholine - stimulates muscle contraction
Monoamines - Norepinephrine & Dopamine (sense of feeling good, low levels = depression)
Serotonin (sleepiness) and mood
Endorphins (reduce pain, inhibit receptors)

21. Neurotransmitters
Excitatory - increase membrane permeability, increases chance for threshold to be achieved
Inhibitory - decrease membrane permeability, decrease chance for threshold to be achieved

22. The Action Potential- an All-or-None Electrical Signal

23. Cell Membrane Potential
At rest, the inside of a neuron's membrane has a negative charge. As the figure shows, a Na+ / K+ pump in the cell membrane pumps sodium out of the cell and potassium into it. However,  more potassium ions leak out of the cell. As a result, the inside of the membrane builds up a net negative charge relative to the outside.
Animations of Nerve Impulses
view0/chapter14/animation __the_nerve_impulse.html

24. Action Potential Overview
Signals or impulses of communication
Travel along axons
Are “all-or-none” events
Threshold must be reached
Two phases
Depolarization
Repolarization

25. Axon Diameter and Action Potentials
Recall that axons are also called nerve fibers
Larger fibers propagate impulses faster
Larger fibers usually myelinated
Smallest fibers are unmyelinated and therefore propagate impulses slower

26. Resting Membrane Potential
Recall that there is a separation of charges across the membrane of excitable cells.
Extracellular fluid contains more sodium ions than are found inside a cell
Cytosol contains more anions and negatively charged proteins
Thus sodium ions cling to the outside cell surface

27. Resting Membrane Potential
Cell somewhat permeable to potassium
Much less permeable to sodium
Sodium quick to rush in when gates open
following both electrical and concentration gradients
Potassium not quick to rush out
only has concentration gradient to drive flow

28. Resting Membrane Potential
small build-up of anions in cytosol
equal build-up of cations in extracellular fluid

29. Change in Membrane Potential
Na+ channels open
Fast Na+ influx
Inside of cell becomes less negative
If change is +15mV action potential occurs

30. Ongoing Research
Improve environment for spinal cord axons to bridge injury gap
Find ways to stimulate dormant stem cells to replace lost, damaged, or diseased neurons
Develop tissue cultured neurons that can be used for transplantation purposes.

31. Drugs that Affect Synapses and Neurotransmitters
Strychnine poisoning can be fatal to humans and animals and can occur by inhalation, swallowing or absorption through eyes or mouth
Strychnine is a neurotoxin which acts as an antagonist of acetylcholine receptors. It primarily affects the motor nerves in the spinal cord which control muscle contraction. An impulse is triggered at one end of a nerve by the binding of neurotransmitters to the receptors.   
Strychnine use by athletes?  
Used as a pesticide to kill rats
Also found mixed with street drugs such as LSD, heroin and coke

32. Drugs that Affect Synapses and Neurotransmitters
Cocaine, morphine, alcohol, ether and chloroform
Ecstasy

33. LSD  (hallucinogen)

34. Dangers of Ecstasy (MDMA)
The most common cause of Ecstasy-related death is overheating (hyperthermia). MDMA interferes with the body's ability to regulate its own body temperature and to see other warning signs allowing the body to overheat without discomfort especially when dancing for hours in hot clubs.
The neurotransmitter serotonin is vital in regulating many of our basic functions. Serotonin is, among other things, the feel good neurotransmitter and helps to regulate body temp.
Our brain cells are constantly trying to bring some amount of serotonin back into the cells and out of the synapse using serotonin reuptake transporters. 
Ecstasy essentially takes these upkeep transporters and reverses their roles. This causes a massive flood of serotonin from the brain cells into the synapse. 

35. LSD; lysergic acid diethylamide
Actions/Effects: LSD alters the action of the neurotransmitters serotonin, norepinephrine, and dopamine, triggering extreme changes in brain function. Physical effects include increased body temperature, heart rate, and blood pressure. Psychological effects include perceptual and thought distortions, hallucinations, delusions, and rapid mood swings.
Cocaine blocks reuptake of dopamine

36. Central Nervous System
Integrates and correlates incoming sensory information
Source of thoughts, emotions, memories
Most motor signals originate in CNS

37. CNS (CENTRAL NERVOUS SYSTEM) Spinal Cord and Brain
4 Divisions of the brain:
Brainstem
Cerebellum
Diencephalon
Cerebrum
Brainstem
Medulla Oblongata
Pons
Midbrain
Cerebellum
Diencephalon
Hypothalamus
Thalamus
Cerebrum

38.                       .

39. BRAINSTEM - extension of the _________
* Medulla Oblongata: largest part of the brainstem.
- extension of the _________
- Location: lies below the _______
- Functions: reflex center
-It controls:
* Medulla Oblongata: largest part of the brainstem.
- extension of the spinal cord
- Location: lies below the pons and the midbrain
- Functions: reflex center (control heartbeat, respiration and blood vessel diameter)
PONS- functions in sensory analysis;

42. DIENCEPHALON Hypothalamus: - Structure:
- Function: Acts as the major center for
controlling the _____. (function of internal
organs)
- Controls _____________
- Centers for controlling:
Dienceph-deep in core of brain; sits on top of brainstem
2 main parts: thalamus and hypo
Hypothalamus:
- Structure: consists mainly of the posterior pituitary gland, pituitary stalk and gray matter.
- Function: Acts as the major center for
controlling the ANS. (function of internal
organs)
- Controls hormone secretion
- Centers for controlling appetite, wakefullness and pleasure

44. DIENCEPHALON THALAMUS:
- Structure: dumbbell shaped mass of gray matter in each cerebral hemisphere
- Function:
- Produces emotions of pleasantness and unpleasantness associated with sensation
- Structure: dumbbell shaped mass of gray matter in each cerebral hemisphere
- Function: relays sensory impulses to cerebral cortex
- Produces emotions of pleasantness and unpleasantness associated with sensation

46. CEREBELLUM Second largest part of the brain Structure:
- composed of _____in outer layer and _______in the inner layer
Function:
Second largest part of the brain
Structure: Lies under the occipital lobe of the cerebrum
- composed of gray matter in outer layer and white matter in the inner layer
Function: helps control muscle contractions to produce coordinated movements.
Also, maintain balance, move smoothly and sustain normal posture

48. CEREBRUM Largest part of the brain
Structure: Structures: Series of ridges and grooves
-Ridges are called convolutions or ____
-Grooves are called _____ (deepest sulci are called fissures)
-Divided into two halves- ________
-Hemispheres connected by the _________
Largest part of the brain
Structure: Structures: Series of ridges and grooves
-Ridges are called convolutions or Gyri
-Grooves are called Sulci (deepest sulci are called fissures)
-Divided into two halves- Hemispheres
-Hemispheres connected by the Corpus callosum

51. CEREBRUM HEMISPHERES: Divided into lobes
Lobes are named after bones that lie over them.

52. CEREBRUM Function: mental process of all types Sensations
Consciousness
Thinking
Memory
Willed Movements

53. Cerebrum Specific areas have specific functions
Temporal lobe’s auditory areas interpret incoming nervous signals as specific sounds
Visual area of the occipital lobe helps you understand and identify images
If a specific part of the brain is damaged, for example the Primary Taste Area, you would not be able to taste things.

54. __________CEREBRUM

55. SPINAL CORD Structure: Outer part composed of white matter
- Interior part composed of gray matter
Function: center of all spinal cord reflexes
- sensory tracts conduct impulses ___ the brain.
- motor tracts conducts impulses ____ the brain To
From

56. Cutting the Cord
Completely severing the spinal cord produces a loss of sensation for all areas below the cut, called anesthesia.
It also produces a loss of the ability to make voluntary movements, called paralysis.

58. Peripheral Nervous System (PNS) Cranial and Spinal Nerves
Function:
Cranial Nerves:
- 12 pairs of cranial nerves
- Functions vary

61. SPINAL NERVES
Structure: contain dendrites of sensory neurons and axons of motor neurons
Function: conduct impulses necessary for sensations and voluntary movements
Connect the Brain and Spinal Cord to Peripheral structures like skin and muscles.

63. Autonomic Nervous System (ANS)
Structure: Consists of motor neurons that conduct impulses from spinal cord or brainstem to:
1. Cardiac Muscle tissue
2. Smooth muscle tissue
3. Glandular epithelial tissue
Function:
Structure: Consists of motor neurons that conduct impulses from spinal cord or brainstem to:
1. Cardiac Muscle tissue
2. Smooth muscle tissue
3. Glandular epithelial tissue
Function: regulate involuntary functions
- heartbeat, contractions of the stomach and intestines and secretions by glands

64. 2 Divisions of ANS 1. Sympathetic nervous system: -Structure:
-Function:
1. Sympathetic nervous system:
-Structure: dendrites and cell bodies located in gray matter of the thoracic and upper lumbar segments of the spinal cord
-Function: serves as the emergency or stress system during strenuous exercise and strong emotions (hate, anger, fear or anxiety)
- controls the “ fight or flight” response

65. 2 Divisions of ANS 2. Parasympathetic Nervous System: Structure:
Function:

67. Autonomic Neurotransmitters
Each division of the ANS signals its effectors with a different neurotransmitter.
This is how an organ can tell which division is stimulating it.
Ex. The heart responds to acetylcholine from the parasympathetic division by slowing down. If norepinephrine, from the sympathetic division, is present, the heart speeds up.

68. ANS as a Whole
Regulates the body’s autonomic functions in ways that maintain HOMEOSTASIS