chapter 11.txt

  1. Plasma Membrane
    • * Barrier to cell contents
    • * Double layered
    • * Embedded with proteins, Cholesterol, and Glycoproteins
  2. What happens when potassium moves out?
    • * The change in voltage is known as an action potential
    • Function of the nervous system
    • * Sensory: monitor changes that occur outside and inside the body
    • * Integration: process the information
    • * Motor: sends response
    • 1. Receive
    • 2. Process
    • 3. output
  3. How does a signal travel from one neuron to another?
    • * Neurons from chemical connetions called synapse
    • * Axon terminals of one neuron (presynapse=send) from a synapse with the dendrites of another neuron (postsynapse=receive)
    • * The space in between the two neurons is called the synapse cleft
    • Functional classification of neurons
    • * Sensory: known also as Afferent INPUT
    • o Neurons that carry information to the CNS
    • o Seeing hearing touching etc
    • * Motor: known also as Efferent OUTPUT
    • o Neurons that carry information away from the CNS
    • o Moving muscles, smiling, exhaling, taking notes, etc.
    • o Could be somatic (voluntary) or automatic (involuntary)
    • * Interneurons: known as association neurons
    • o Found in the CNS
    • o Connected to sensory and motor neurons
    • o [responsible for integrating ]
  4. Anatomy of synapse
    • * Axon terminals of the presynapse cell contain vesicles
    • * These vesicles are filled with chemicals known as neurotransmitters
    • [Communication between neurons are mediated by NT]
    • * Upon stimulation the NT are released into the Synapse cleft
    • * The NT binds to the protein channels on the postsunaptic neuron causing it to be activated
  5. Components of the nervous system
    • * Central nervous system (CNS)
    • o Brain & spinal cord
    • * Peripheral nervous system (PNS)
    • o Cranial and spinal nerves
    • * The functional nervous cells are called neurons
    • * Two major types of cells
    • o Neurons (excitable cells)
    • o Neurogial cells (support cells)
  6. Nerve
    • * Made of many axon bundled together
    • * Surrounded by connective tissue called epineurium
    • * Made of many fascicles
  7. Structure of a neuron
    • * Cell body is the central command cell where the nucleus is located
    • * Dendrites are extensions of the cell body that receives electrical signals
    • * Axons conduct impulses away from cell body
    • * Axon terminals contain vesicles filled with neurotransmitters
  8. Neurons and Glial
    • * Schwann cells produce myelin that insulate the axon
    • * Nodes of Ranvier are gaps in myelin sheath along the axon
  9. What ions are found around the neuron?
    • * Sodium is found outside the neuron
    • * Potassium is found inside the neuron
  10. Structure of a nerve
    • * Each fascicle is surrounded by a membrane called perineurium
    • * Within in each facsicle, many nerve fibers are grouped
    • * Each nerve fiber is surrounded by a membrane called endoneurium
  11. How neurons work together
    • * Sensory neurons, receive a signal and send it from the PNS to the CNS
    • * Interneurons in the CNS receive the signal and send it to motor neurons
    • * Motor neurons send signal out of the CNS to PNS causing a response
    • Structural classification of neurons
    • * Multipolar neurons:
    • o Have many dendrites
    • o Found in the brain and spinal cord
    • * Bipolar neurons
    • o Have two processes
    • o One is an axon, the other is a dendrite
    • o Found in eyes, nose, and ears
    • * Unipolar neurons
    • o Have single branches into two
    • o The cell bodies aggregate forming ganglia
  12. Resting potential
    • * Both sodium and potassium move by diffusion
    • * When permitted, sodium moves into the cell and potassium moves out of the cell
    • * Since Na+ and K+ are positively charged, when Na moves in, the cell becomes more positive
    • * When K moves out, the cell becomes less positive (more negative)
    • * At rest, Na is outside the cell
    • * K is inside the cell
  13. Component of the nervous system
    • * Two types of cells
    • o Neurons
    • o Neuroglial cells [support cells]
  14. Diffusion
    • * Molecules or ions move from region of high concentration to a region of low concentration
    • * The difference in concentration is known as concentration gradient
  15. Types of neuroglial cells
    • * Astrocytes
    • o Star-shaped cells
    • o Most abundant
    • o Form between capillaries and neurons
    • o Control the concentration of ions within the tissue
    • [fascilitated]
    • * Microglia
    • o Spider-like phangocytes
    • o Dispose of debris
    • [Protection]
    • * Ependymal cells
    • o Lines the cavities of the brain and spinal cord
    • o Circulated cerebrospinal fluid
    • * Oligodendrocytes
    • o Produce myeline sheath around nerve fibers in the CNS
    • [Myeline]
    • * Satelite cells
    • o Protect cell body of neurons
    • * Shwann cells
    • o Form myelin sheath in the PNS
  16. Neuron
    A neuron is a cells that has a unque shape and structure
Card Set
chapter 11.txt
Fundamentals of the Nervous system and nervous tissue