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Module 3

Module 3. Brain’s Building Blocks. INTRODUCTION. Alzheimer’s disease 10% of cases start after age 50 90% of cases start after age 65 Symptoms: Problems with memory Forgetting and repeating things Getting lost Being mildly confused. INTRODUCTION (CONT’D). Alzheimer’s disease

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Module 3

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  1. Module 3 Brain’s Building Blocks

  2. INTRODUCTION • Alzheimer’s disease • 10% of cases start after age 50 • 90% of cases start after age 65 • Symptoms: • Problems with memory • Forgetting and repeating things • Getting lost • Being mildly confused

  3. INTRODUCTION (CONT’D) • Alzheimer’s disease • Period of 5 to 10 years, symptoms worsen • Result is profound memory loss • Lack of recognition of family and friends • Deterioration in personality • Emotional outbursts • Widespread damage to the brain (hippocampus, involved in memory) • no cure; always fatal

  4. INTRODUCTION (CONT’D) • Alzheimer’s disease • Diagnosis and causes • _____________________________________________ • _____________________________________________ • _____________________________________________ • _____________________________________________ • Certain chemicals (__________________) that occur naturally in all brains seem to multiply and are believed to cause Alzheimer’s (________________________________)

  5. DEVELOPMENT OF THE BRAIN • Fact that your brain doesn’t develop into a nose is because of instructions contained in your genes • Genes • Chains of chemicals arranged like rungs on a twisting ladder • You have about 20,000 to 25,000 genes that contain chemical instructions equaling roughly 300,000 pages of written instructions • Genes program the development of individual parts into a complex body and brain

  6. DEVELOPMENT OF THE BRAIN (CONT’D)

  7. STRUCTURE OF THE BRAIN • Human brain • Shaped like a small, wrinkled melon • 1,350 grams (less than three pounds) • Pinkish-white color • Consistency of firm Jell-O • Fueled by sugar (glucose) • 1 trillion cells divided into • ___________________ • ___________________

  8. STRUCTURE OF THE BRAIN (CONT’D) • Glial cells • _______________________________________ • ______________________________________________________________________________________________________________________________ • ______________________________________________________________________________________________________________________________

  9. STRUCTURE OF THE BRAIN (CONT’D)

  10. STRUCTURE OF THE BRAIN (CONT’D) • Neuron • ________________________________________ • ________________________________________ • ________________________________________________________________________________________________________________________________________________________________________

  11. Neuron

  12. GROWTH OF NEW NEURONS (CONT’D) • Repairing the brain • Advances in stem research suggest the human brain may be able to grow more neurons • Repair damages due to • accident • disease • Alzheimer’s

  13. BRAIN VERSUS MIND • Mind-body question: • How complex mental activities such as • feeling • thinking • learning • can be explained by the • physical • chemical • electrical activities • of the brain

  14. ALZHEIMER’S DISEASE AND NEURONS • Alzheimer’s disease • Excessive buildup of glue-like substances • Gradually destroy neurons • Researchers can study a person’s mental activities by taking brain scans of the neural activities going on inside the living brain

  15. ALZHEIMER’S DISEASE AND NEURONS

  16. PARTS OF THE NEURON • Cell body • Large egg-shaped structure that provides ______________________________________________________________________________________________________________________________ • Dendrite • Branch-like extensions that arise from the cell body • ____________________________________________________________________________________________ • ________________________________________________________________________________________________________________________________________________________________________________________

  17. PARTS OF THE NEURON (CONT’D) • Axon • A single thread-like structure that extends/carries signals away from the cell body to neighboring neurons, organs, or muscles • Myelin sheath • Looks like separate tube-like segments composed of fatty material that wraps around and insulates an axon • ______________________________________________________________________________________________________________________________

  18. PARTS OF THE NEURON (CONT’D) • End bulbs or terminal bulbs • Located at extreme ends of the axon’s branches • Miniature container that ______________________________________________________________________________________________________________________________ • Synapse • Infinitely small space (20-30 billionths of a meter) • Exists between an end bulb and its adjacent body organ, heart, muscles, or cell body

  19. NEURONS VERSUS NERVES • Reattaching limbs • John Thomas • lost arms in farming accident • Transplanting a face • Isabelle • face severely disfigured by a dog • received • new nose • lips • chin

  20. NERUONS VERSUS NERVES

  21. PERIPHERAL & CENTRAL NERVOUS SYSTEM • Peripheral nervous system • Made up of nerves located throughout the body, ________________________________________________________________________________________________ • Nerves • ___________________________________ that come from the spinal cord and are held together by connective tissue • Carry information from the ________________________________________________________________________________________________ • Those in the peripheral nervous system have the ability to grow or reattach if severed or damaged

  22. PERIPHERAL & CENTRAL NERVOUS SYSTEM (CONT’D) • Central nervous system • Made up of neurons located in the ____________________________________________________________________________________ • Multiple sclerosis • ________________________________________________________________________________________________________________________________________________________________________________________________________

  23. SENDING INFORMATION: ACTION POTENTIAL SEQUENCE • Stimulus (tack or nail) • Skin has sensors that pick up mechanical pressure and transform it into electrical signals • Signals are sent by the neuron’s axon to various areas in the spinal cord and brain • Brain interprets electrical signals as “pain” • axon membrane has chemical gates that can open to allow electrically charged particles to enter or can close to keep out these particles • ions are chemical particles that have electrical charges • Opposite charges attract and like charges repel

  24. SENDING INFORMATION: ACTION POTENTIAL SEQUENCE (CONT’D)

  25. SENDING INFORMATION: ACTION POTENTIAL SEQUENCE (CONT’D) • Resting state • Axon has a charge • Charge results from the axon membrane separating ______________________________________________________________________________________________________________________________ • Sodium pump • Transport process that picks up any sodium ions that enter the axon’s chemical gates and returns them back outside • Results in keeping axon charged by keeping sodium ions outside the axon membrane

  26. SENDING INFORMATION: ACTION POTENTIAL SEQUENCE (CONT’D) • Action potential • ______________________________________________________________________________________________________________________________ • Enormous __________ of sodium ions inside the axon causes the _______________to ___________ its charge • Inside becomes ____________ and outside becomes __________________

  27. SENDING INFORMATION: NERVE IMPULSE

  28. SENDING INFORMATION: NERVE IMPULSE (CONT’D) • Nerve impulse • Nerve impulse is made up of six action potentials, with the first occurring at the beginning of the axon • All-or-none law • If an action potential starts at the beginning of the axon, the action potential will continue at the same speed segment to segment to the very end of the axon

  29. TRANSMITTERS • A transmitter is a chemical messenger that transmits information between nerves and body organs, such as muscles and heart • Excitatory and inhibitory • Excitatory transmitters (agonists) • ________________________________________ • Inhibitory transmitters (antagonists) • ________________________________________

  30. Agonists

  31. Antagonists

  32. NEUROTRANSMITTERS • Neurotransmitters • Dozens of different chemicals made by ____________________________ and then used for ________________ between neurons during the performance of _____________________________________________________________________________ activities

  33. NEUROTRANSMITTERS (CONT’D)

  34. Acetylcholine (ACH) • Deals with motor movement and memory. • Too much and you will…. • Too little and you will… • Lack of ACH has been linked to Alzheimer’s disease.

  35. Dopamine • Deals with motor movement and alertness. • Lack of dopamine has been linked to Parkinson’s disease. • Too much has been linked to schizophrenia.

  36. Serotonin • Involved in mood control. • Lack of serotonin has been linked to clinical depression.

  37. ALCOHOL • Alcohol (ethyl alcohol) • A ____________________________________, which means that it _____________________ the activity of the ____________________________________________________________________________________

  38. ALCOHOL (CONT’D)

  39. WHAT DOES ALCOHOL DO? • Alcohol affects the brain by imitating a naturally occurring neurotransmitter, GABA • GABA neurons • GABA neurons have chemical locks that can be opened by chemical keys in the form of the neurotransmitter GABA • GABA keys • Alcohol molecules so closely resemble those of the GABA neurotransmitter that alcohol can function like GABA keys and open GABA receptors • When GABA neurons are excited, they decrease neural activity

  40. WHAT DOES ALCOHOL DO? (CONT’D) • Many people drink alcohol to feel less anxious and more relaxed • Appears to be a biological link between alcohol and anxiety • Deficiency in a specific brain protein is associated with high anxiety and excessive alcohol use

  41. Neurotransmitters

  42. NEW TRANSMITTERS • Number of well-known neurotransmitters, such as • Norepinephrine • GABA • Dopamine • Serotonin

  43. NEW TRANSMITTERS (CONT’D) • Endorphins (1970s) • painkiller similar to morphine • decreases effects of pain during great bodily stress • Anandamide (1990s) • similar to THC (active ingredient in marijuana) • involved with • memory • motor coordination • emotions

  44. NEW TRANSMITTERS (CONT’D) • Anandamide may help people regulate emotions, which would help them to better deal with anxiety and stress • Nitric oxide (mid-1990s) • may be involved in regulating aggressive and impulsive behaviors

  45. NEW TRANSMITTERS (CONT’D) • Orexin (hypocretin) • late 1990s • involved in the brain’s pleasure and reward system • high levels: ____________________________ • low levels: ______________________________ • involved in sleep and wakefulness • _____________________________________

  46. REFLEX • Reflex • ______________________________________________________________________________________________________________________________ • ________________________________________________________________________________________________________________________________________________________________________

  47. REFLEX (CONT’D) • Reflex sequence • Sensors • ________________________________________________________________________________________________________________________ • Afferent neurons (sensory neurons) • ________________________________________________________________________________________________________________________

  48. REFLEX (CONT’D) • Interneuron • relatively short neuron whose primary task is ________________________________________________________________________________________________________________________ • Efferent neuron • ________________________________to produce ____________________ in various muscles and organs throughout the body

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