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CELL COMMUNICATION
http://www.youtube.com/watch?v=U6uHotl
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Cells in both multicellular and unicellular
organisms need to communicate in order
to coordinate activities.
Ex. How does your brain communicate to
your stomach that you are full
Cells use various methods of
communication.
Ex. Nerve signals and hormone signals
HORMONE SIGNALS
 Act slowly and in small amounts
 Influenced by factors in the environment and body
 Dif ferent hormones have dif ferent ef fects on tissues,organs,
and metabolism
 Hormones can only af fect those cells that have receptors for
those hormones
 A signaling cell produces a signal, that is detected by the
target cell.
 Typically, target cells have specific proteins that recognize
and respond to the signal.
T YPES OF HORMONES
 TSH – Stimulates the thyroid
(role in metabolism)
 Growth Hormone – stimulates
body cells to increase in size –
major targets bones
 Antidiuretic hormone – influence
water balance in the body –
targets kidneys
 Pancreatic hormones – regulate
blood sugar
NERVE SIGNALS
 Rapid communication
throughout body
 Voluntary and involuntary
control
 Use neurotransmitters
 Neighboring cells can communicate through direct contact
between their membranes.
 Long-distance signals are carried by hormones and nerve
cells.
 A target cell is bombarded by hundreds of signals. But it
recognizes and responds only to the few signals that are
important for its function.
 This response to some signals, but not to others, is made
possible by receptor proteins, such as the ones in the cell’s
membrane.
DISRRUPTIONS OF COMMUNICATION
 When communication fails it can impact how your body
functions
 Ex. Certain drugs can mimic and block hormones and nerve
receptors
 Certain diseases are caused by an interruption of cell
communication ex. Muscular sclerosis, diabetes
Cell communication sometimes involves multiple steps and multiple signals
That can target many different organs and tissues.