The Nervous System

1. The Nervous System

2. Structural Classification of the Nervous System • Central nervous system (CNS) • Brain • Spinal cord • Represents the input and output pathways • Peripheral nervous system (PNS) • Nerve outside the brain and spinal cord • Afferent ( towards CNS) and Efferent ( to peripheries) • Efferent is broken down into the somatic and autonomic systems

3. 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. Motor output • A response to integrated stimuli • The response activates muscles or glands

4. Nervous Tissue: Support Cells (Neuroglia or Glia) • Made of Neurons and neuroglia • Astrocytes ( look like stars) • Metabolic and structural support cells • Control the chemical environment of the brain (CNS) Figure 7.3a

5. Nervous Tissue: Support Cells • Microglia (CNS) • Spider-like phagocytes • Dispose of debris • Ependymal cells (CNS) • Line cavities of the brain and spinal cord Figure 7.3b, c

6. Nervous Tissue: Support Cells • Oligodendrocytes(CNS) • Hold nerve fibers together • Produce myelin Figure 7.3d

7. Nervous Tissue: Neurons • Neurons = nerve cells • Cells specialized to transmit messages from one cell to another

8. Neuron Anatomy • Cell body • Nucleus • Large nucleolus Figure 7.4a

9. Neuron Anatomy • Extensions outside the cell body • Dendrites – conduct impulses toward the cell body • Axons – conduct impulses away from the cell body (only 1!) Figure 7.4a

10. Spaces between axon terminals and receiving cells called SYNAPSES • NEUROTRANSMITTERS help signals jump synapses to the next neuron • Neurons can be • MULTIPOLAR ( 1 axon, many dendrites) • BIPOLAR (1 axon, 1 dendrite) • UNIPOLAR One process that extends from the cell body

11. The Human Brain

12. FACTS • The human brain weighs 3lbs and is made of 100 billion neurons. • Protected by the cranium ( skull) • It is protected by 3 different membranes called meninges. • Blood and oxygen is a must. • Brain damage will occur within 4 to 8 minutes without it.

13. Brain Anatomy • 3 Main Parts • Cerebrum • Cerebellum • Brain Stem

14. Brain Anatomy Meninges/Coverings • Dura mater - outermost layer • Subdural hematoma • Arachnoid mater  -  no blood vessels, in between layer (resembles a spider web) • Pia mater -inner membrane, contains nerves and blood vessels to nourish cells Cerebrospinal Fluid • Fills space between the arachnoid and the pia mater • Serves as a liquid shock absorber

15. Dura mater is being peeled away in this photo.

16. The Cerebrum

17. Brain Anatomy 4 Lined Cavities/Ventricles • Right and Left (Lateral) Ventricles • Largest; inside the cerebral hemisphere • Third Ventricle • Behind and below lateral ventricles • Fourth Ventricle • Below the third, in front of the cerebellum and behind the pons and medulla

18. Cerebral Cortex CerebralCortex Cerebral Cortex - The outermost layer of gray matter making up the superficial aspect of the cerebrum. Highest center of reasoning and intellect. Conscious thought, judgment, memory, reasoning and willpower! Makes humans the most intelligent of all animals

19. Cerebrum Cerebrum Cerebellum Cerebrum -The largest division of the brain. It is divided into two hemispheres, each of which is divided into four lobes Covered with fissures which are deep and sulci which are shallow. Also have elevated ridges called gyri

20. Cerebral Features: • Gyri – Elevated ridges “winding” around the brain. • Sulci – Small grooves dividing the gyri • Central Sulcus – Divides the Frontal Lobe from the Parietal Lobe • Fissures – Deep grooves, generally dividing large regions/lobes of the brain • Longitudinal Fissure – Divides the two Cerebral Hemispheres • Transverse Fissure – Separates the Cerebrum from the Cerebellum • Sylvian/Lateral Fissure – Divides the Temporal Lobe from the Frontal and Parietal Lobes

21. Gyri (ridge) Sulci (groove) Fissure (deep groove)

22. 4.  Fissures – separate lobes Longitudinal fissure - separate right and left sides

23. Transverse Fissure - separates cerebrum from cerebellum

24. Lateral Fissure separates the temporal lobe from the Frontal and Parietal lobes

25. : Central Sulcus Longitudinal Fissure Sylvian/Lateral Fissure Transverse Fissure http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif

26. THE CEREBRUM: • Two divisions made by the longitudinal fissure • Left brain functions Right brain function • Analytical Thoughts Holistic thoughts • Logic Intuition • Language Creativity • Science/ Math Art and music Connect with each other through Corpus Collosum

27. Are you right or left brain dominant?

28. Frontal Parietal Occipital Temporal Lobes of the Brain (4) http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

29. The Frontal Lobe of the brain is located deep to the Frontal Bone of the skull. Lobes of the Brain - Frontal • It plays an integral role in the following functions/actions: • - Memory Formation • - Emotions • - Decision Making/Reasoning • - Personality • - Voluntary Muscles • - Speech (Investigation: Phineas Gage) Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

30. The Parietal Lobe of the brain is located deep to the Parietal Bone of the skull. Lobes of the Brain - Parietal Lobe • It plays a major role in the following functions/actions: • Senses and integrates sensation(s) • Pain, touch , heat and cold • Spatial awareness and perception • (Proprioception - Awareness of body/ body parts in space and in relation to each other) • - distance, size and shape Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

31. Lobes of the Brain – Occipital Lobe • The Occipital Lobe of the Brain is located deep to the Occipital Bone of the Skull. • Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli. Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

32. Lobes of the Brain – Temporal Lobe • The Temporal Lobes are located on the sides of the brain, deep to the Temporal Bones of the skull. • They play an integral role in the following functions: • Hearing • Organization/Comprehensionof language • Information Retrieval (Memory and Memory Formation) Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

33. Cerebellum • 2 hemispheres/wings • Balance and coordination to do with skeletal muscles • Maintains Balance: sensory receptors in inner ear • Maintenance of Muscle Tone • Coordination of Muscle Movements: Allows muscles to contract at right time with right strength • Injury results in motor impairment

34. Investigation Phineas Gage: Railroad worker in the 19th century living in Cavendish, Vermont. Set off explosive charges in large rock During a detonation occurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rod to be blown right up through his skull and out the top Rod entered his skull below his left cheek bone and exited after passing through the anterior frontal lobe of his brain.

35. Remarkably, Gage never lost consciousness Suffered little to no pain Was awake and alert when he reached a doctor approximately 45 minutes later. He had a normal pulse and normal vision, and following a short period of rest, returned to work several days later . However, he was not unaffected by this accident. http://www.sruweb.com/~walsh/gage5.jpg Frontal

36. Pre-accident Gage as hard-working, responsible, and "a great favorite" with the men in his charge After Gage's accident, "considered the change in his mind so marked that they could not give him his place again His personality was fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), impatient of restraint and obstinate, devising many plans of future operations then abandoning ideas ( couldn’t make decisions) Before his injury he had a well-balanced mind, shrewd, smart business man, very energetic and persistent in executing all his plans of operation.

38. BRAIN STEM: 3 Parts • Regulates visceral functions (autonomic system) • Midbrains • Pons • Medulla Oblongata

39. Midbrain Medulla Oblongata Pons

40. Midbrain – vision, eye movements, hearing Pons - relay sensory information Medulla oblongata – heart, respiration, Blood Pressure, Center for swallowing and vomiting DAMAGE TO BRINSTEM CAN RESULT IN COMA

41. Diencephalon         has 2 parts..... Thalamus - relay station to and from peripheral nervous system Damage to this area results in increased sensitivity to pain or loss consciousness. Hypothalamus –” Brain of the brain “ Function is to control: 1. Autonomic Nervous System 2. Cardiovascular Control: HR B/P 3. Temperature control 4. Gastrointestinal control 5.Manufactures oxytocin 6. Water Control 7. Emotional State 8. Sleep Control 9. Mind Over Body Experiences

42. Corpus callosum Thalamus Pineal gland Hypothalamus

43. Located just under the Cerebrum • Plays a key roll in your EMOTIONAL life • Added functions with memories and smell.  • Crayolas are created today with the same scent because it reminds people of their happy times in childhood. The LIMBIC SYSTEM

44. Memory is controlled by the HIPPOCAMPUS (“sea horse”; that’s its shape) • In ALZHEIMERS disease , hippocampus is one of the first parts of brain to be damaged. HIPPOCAMPUS

45. We used to classify memory as being Long-term: Infinite amount of space can last a lifetime Short-term: 7&2 ( Miller Law) number of things that can be stored in short term memory: less than one minute We can use other types of memory to assist short term memory MEMORY

47. Long term Memory • Long-term: Infinite amount of space can last a lifetime

48.  Episodic Memory Involved in remembering personal experiences, such as a phone conversation you had yesterday or the movie you watched last week. Challenge: Do you remember the first Harry Potter movie?  What was the story?  How many details do you remember?

49. Manages the storage and retrieval of general knowledge of facts, such as the number of days in a year or the colors in a rainbow.  Naming objects is also semantic memory. Semantic Memory Tasks 1. What do you call this thing? 2. Where do Kangaroos live?3. What actor played Bella in Twilight? Semantic Memory

50. Allows us to learn activities and skills that will then be performed automatically with little or no conscious thought. Examples are riding a bicycle or driving a car. Do you know how to use a can opener? Procedural Memory