• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content

Loading…

Flash Player 9 (or above) is needed to view presentations.
We have detected that you do not have it on your computer. To install it, go here.

Like this presentation? Why not share!

Module 03

on

  • 2,146 views

Brain's Building Blocks

Brain's Building Blocks

Statistics

Views

Total Views
2,146
Views on SlideShare
2,146
Embed Views
0

Actions

Likes
1
Downloads
0
Comments
1

0 Embeds 0

No embeds

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

11 of 1 previous next

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Module 03 Module 03 Presentation Transcript

    • Module 3 Brain’s Building Blocks
    • DEVELOPMENT OF THE BRAIN
      • fact that your brain does not develop into a nose is because of instructions contained in your genes
      • Genes
        • chains of chemicals that are arranged like rungs on a twisting ladder
        • there are about 20,000-25,000 genes that contain chemical instructions that equal about 300,000 pages of written instructions
        • genes program the development of individual parts into a complex body & brain
    • DEVELOPMENT OF THE BRAIN (CONT.)
    • DEVELOPMENT OF THE BRAIN (CONT.)
    • STRUCTURE OF THE BRAIN
      • Human brain:
        • is shaped like a small wrinkled melon
        • 1,350 grams (less than 3 pounds)
        • pinkish-white color
        • consistency of firm Jell-O
        • Fueled by sugar (glucose)
        • 1 trillion cells divided into
          • glial cells
          • neurons
    • STRUCTURE OF THE BRAIN (CONT.)
    • STRUCTURE OF THE BRAIN (CONT.)
      • Glial cells
      • 3 Functions:
        • guide the growth of developing neurons
        • wrap around neurons and form an insulation to prevent interference from other electrical signals
        • release chemicals that influence a neuron’s growth and function
    • STRUCTURE OF THE BRAIN (CONT.)
      • Neuron
        • a brain cell with 2 specialized extensions
        • one extension is for receiving electrical signals
        • the other extension is for transmitting electrical signals
    • GROWTH OF NEW NEURONS
      • Can a brain grow new neurons?
        • canary brain
          • can grow about 20,000 neurons a day during the spring (learns new breeding song)
        • primate and human brain
          • researchers conclude that adult monkey and human brains are capable of growing relatively limited numbers of neurons throughout adulthood
          • Some new neurons play important role in continuing to learn and remember new things (hippocampus)
    • GROWTH OF NEW NEURONS (CONT.)
      • Repairing the Brain
        • advances in stem research suggest the human brain may be able to grow more neurons
        • repair damages:
          • accident
          • disease
          • Alzheimer’s
    • PARTS OF THE NEURON
    • PARTS OF THE NEURON
      • Cell Body
        • large egg-shaped structure that provides fuel, manufactures chemicals, and maintains the entire neuron in working order
    • PARTS OF THE NEURON
      • Dendrite
        • branchlike extensions that arise from the cell body
        • receive signals from other neurons, muscles, or sense organs
        • pass these signals onto the cell body
    • PARTS OF THE NEURON
      • Axon
        • a single threadlike structure that extends from and carries signals away from the cell body to neighboring neurons, organs, or muscles
    • PARTS OF THE NEURON
      • Myelin Sheath
        • looks like separate tubelike segments composed of fatty material that wraps around and insulates an axon
        • prevents interference from electrical signals generated in adjacent axons
    • PARTS OF THE NEURON
      • End bulbs or Terminal bulbs
        • located at extreme ends of the axon’s branches
        • miniature container that stores chemicals called neurotransmitters (used to communicate with neighboring cells)
    • PARTS OF THE NEURON
      • Synapse
        • infinitely small space (20-30 billionths of a meter)
        • exists between and end bulb and its adjacent body organ (e.g. heart), muscles (e.g. head), or cell body
    • ALZHEIMER’S DISEASE AND NEURONS
      • Alzheimer’s disease
        • excessive buildup of gluelike substances
        • gradually destroy neurons
      • Researchers recently discovered an experimental vaccine that may help stop the buildup of these gluelike, killer substances and they continue to search for other interventions
    • ALZHEIMER’S DISEASE AND NEURONS
    • PERIPHERAL & CENTRAL NERVOUS SYSTEM
      • Peripheral Nervous System (PNS)
        • made up of nerves that are located throughout the body, except in the brain & spinal cord
      • Central Nervous System (CNS)
        • made up of neurons located in the brain & spinal cord
    • PERIPHERAL & CENTRAL NERVOUS SYSTEM (CONT.)
      • Nerves
        • stringlike bundles of axons and dendrites that come from the spinal cord and are held together by connective tissue
        • carry information from the senses, skin, muscles, and the body’s organs to and from the spinal cord
        • nerves in the peripheral nervous system have the ability to grow or reattach if severed or damaged
    • SENDING INFORMATION: ACTION POTENTIAL SEQUENCE
        • 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
    • SENDING INFORMATION: ACTION POTENTIAL SEQUENCE (CONT.)
    • SENDING INFORMATION: ACTION POTENTIAL SEQUENCE (CONT.)
      • Resting state
        • the axon has a charge
        • the charge results from the axon membrane separating positive ions on the outside from negative ions on the inside
    • SENDING INFORMATION: ACTION POTENTIAL SEQUENCE (CONT.)
      • Action potential
        • tiny electric current that is generated when the positive sodium ions rush inside the axon
        • enormous increase of sodium ions inside the axon causes the inside of the axon to reverse its charge
        • inside becomes positive and outside becomes negative
    • SENDING INFORMATION: ACTION POTENTIAL SEQUENCE (CONT.)
    • SENDING INFORMATION: NERVE IMPULSE
      • Sending information
        • action potential is a tiny electrical current that is generated when the positive sodium ions rush inside the axon
        • the enormous increase of Na ions inside the axon causes the inside to reverse its charge
        • the inside becomes positive & the outside becomes negative
    • SENDING INFORMATION: NERVE IMPULSE (CONT.)
      • 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
      • Nerve impulse
        • nerve impulse is made up of 6 action potentials, with the first occurring at the beginning of the axon
    • 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
          • open chemical locks and turn on neurons
        • inhibitory transmitters
          • block chemical locks and turn off neurons
    • NEUROTRANSMITTER
      • Neurotransmitters
        • dozens of different chemicals that are made by neurons and then used for communication between neurons during the performance of mental or physical activities
    • ALCOHOL
      • Alcohol (ethyl alcohol)
        • A psychoactive drug that is classified as a depressant, which means that it depresses the activity of the central nervous system
    • ALCOHOL
    • 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
    • WHAT DOES ALCOHOL DO? (CONT.)
      • 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
    • NEW TRANSMITTERS
      • Number of well-known neurotransmitters, such as
        • Acetylcholine
        • GABA
        • Norepinephrine
        • Epinephrine
        • Dopamine
        • Serotonin
    • NEW TRANSMITTERS (CONT.)
      • New
        • Endorphins (1970’s)
          • painkiller similar to morphine
          • decreases effects of pain during great bodily stress
        • Anandamide (1990’s)
          • similar to THC (active ingredient in marijuana)
            • involved with
              • memory
              • motorcoordination
              • emotions
    • NEW TRANSMITTERS (CONT.)
      • Anandamide may help people regulate emotions, which would help them to better deal with anxiety and stress
        • Nitric oxide (mid-1990’s)
          • may be involved in regulating aggressive and impulsive behaviors
    • REFLEX
      • Reflex
        • unlearned, involuntary reaction to some stimulus
        • neural connections underlying a reflex are prewired by genetic instructions
    • REFLEX (CONT.)
      • Reflex sequence
        • sensors
          • sensors trigger neurons that start the withdrawal effect
        • afferent neurons
          • carry information from the senses to the spinal cord
    • REFLEX (CONT.)
        • Interneuron
          • relatively short neuron whose primary task is making connections between other neurons
        • Efferent neuron
          • carry information away from the spinal cord to produce responses in various muscles and organs throughout the body
    • REFLEX (CONT.)
    • PARKINSON’S DISEASE
      • Parkinson’s Disease
        • includes symptoms of tremors and shakes in the limbs, a slowing of voluntary movements, muscle stiffness, problems with balance and coordination and feelings of depression
        • as the disease progresses, patients develop a shuffling walk and may suddenly freeze in space for minutes or hours at a time
        • Michael J. Fox
    • PARKINSON’S DISEASE (CONT.)
      • Parkinson’s Disease
        • it is caused by destruction of neurons that produce dopamine
        • L-dopa is a medication that boosts the levels of dopamine in the brain
        • eventually the drug causes involuntary jerky movements
        • after prolonged use, L-dopa’s beneficial effect may be replaced by unwanted jerky movements
    • EXPERIMENTAL TREATMENTS
      • Sterotaxic procedure
        • fixing a patient’s head in a holder and drilling a small hole through the skull
        • the holder has a syringe that can be precisely guided into a predetermined location in the brain
    • EXPERIMENTAL TREATMENTS
    • EXPERIMENTAL TREATMENTS
    • EXPERIMENTAL TREATMENTS
      • Removing part of the brain
        • Thalamotomy (Michael J. Fox)
      • Brain Stimulation
        • electrodes placed into thalamus
        • patient controls amount of stimulus
        • helps reduce tremors
    • EXPERIMENTAL TREATMENTS