The endocrine system

  1. Function of chemical messengers
    To relay information and instructions between cells
  2. Gap junction communication
    Communication between adjacent cells through the exchange of ions
  3. Example of direct communication
    Gap junction communication-Communication between cells of the same type-Must have extensive physical contact
  4. Details about endocrine system
    Contains 30 hormones that regulate= body temperature, sleep, hunger, stress management, growth development and reproduction.
  5. Hormones
    Chemical messengers to relay information and instructions between cells

    Chemical messengers that are released in one tissue and transported in bloodstream to alter activities of specific cells in other tissues

    Have a known chemical structure
  6. Paracrine
    Neighbor signalling Local hormones (Prostaglandins)
  7. Function of gap junctions
    -Coordinate ciliary movement among epithelial cells-Coordinate cardiac muscle cell contraction-Facilitate propagation of action potentials
  8. Difference between paracrine and hormones (endocrine)
    1. Most cells release paracrine signals/factors

    2. Specialized cells release hormones

    3. Hormones can stimulate the same cell type or can affect distant cells as well.
  9. What do hormones alter?
    They coordinate cellular activities of tissues in distant portions of the body.

    Alter operations of genes, existing proteins (and the rate of synthesis of proteins (by changing the rate of transcription and translation)

    Turn an existing enzyme or membrane channels "on" or "off" by changing its shape or structure.
  10. If hormones travel all over the body, can they activate the wrong cell type?
    Even though all cells get exposed to said hormone they may not have the functional (necessary) receptor.
  11. How can hormones affect tissues?
    Hormones can modify the physical structure or biochemical properties of its target cells. This target cells can be affected by one hormone, Slowly altering the cells metabolic functions, then the tissues and finally the organs.
  12. Direct communication
    transmission: Through gap junctions

    Chemical mediators: Ions, small solutes, lipid soluble materials

    Distribution of effects: Usually limited to adjacent cells of the same type that are interconnected by connexons.
  13. Paracrine communication
    Transmission: Through extracellular fluid

    Chemical Mediators: Paracrine factors

    Distribution of effects: Primarily limited to local area, where concentrations are relatively high. Target cells must have appropriate receptors.
  14. Endocrine communication
    Transmission: Through the circulatory system

    Chemical Mediators: Hormones

    Distribution of effects: Target cells are primarily in other tissues and organs and must have appropriate receptors.
  15. Synaptic communication
    Transmission: Across synaptic clefts

    Chemical Mediators: Neurotransmitters

    Distribution of effects: Limited to very specific area. Target cells must have appropriate receptors.
  16. What type of molecule is a hormone
    Steroid or amino acid-based
  17. Master endocrine gland that regulates other endocrine organs
    Anterior pituitary
  18. How are hormones regulated
    Negative feedback
  19. Factors
    Have no set chemical structure
  20. As the glucose levels decrease _____ is released by the _______ so cells can take up glucose.

  21. Function of posterior pituitary or hypothalamus
Card Set
The endocrine system
Mechanisms of intracellular communication, introduction to the endocrine system.