Each gland has a

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Endocrine glands are not physically connected but
are scattered throughout the body.
Each gland has a function to regulate bodily
functions.
Diseases can be result of an imbalance or
deficiency of hormone
The glands work together to keep the body in
balance
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• Living cells can function only within a narrow
  range of such conditions as temperature, pH, ion
  concentrations, and nutrient availability, yet
  living organisms must survive in an environment
  where these and other conditions vary from hour
  to hour, day to day, and season to season

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• The human body, for example, maintains blood pH
  within the very narrow range of 7.35 to 7.45. A
  pH below this range is called acidosis and a pH
  above this range is alkalosis. Either condition
  can be life-threatening. One can live only a few
  hours with a blood pH below 7.0 or above 7.7, and
  a pH below 6.8 or above 8.0 is quickly fatal. Yet
  the body's metabolism constantly produces a
  variety of acidic waste products that challenge
  its ability to maintain pH in a safe ran

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Endocrine System

• Primary Function To coordinate physiological
  responses to maintain homeostasis
• (works with the nervous system to do this)
• Physiological- changes inside the body. Such as
  blood pressure, blood sugar level, heart rate

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Endocrine System

• Definition
• The bodys network of glands that produce more
  than 50 different known hormones
• Maintain and regulate body functions, like
  Growth and Development
• Immunity Digestion Reproduction
  Homeostasis

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Nervous System Endocrine System

• Quick Response
• Electrical Signal
• Carried by neurons
• No diffusion

• Slower response, but longer lasting
• Chemical signal (hormones)
• Bloodstream to target organs (have receptors)
• Yes diffusion (thats why its slower)

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Location of Endocrine Glands

• A. Pineal Gland - melatonin (sexual maturity,
  biological circadian rhythms)
• B. Pituitary Gland - FSH (sperm/egg), LH (sex
  hormones)
• C. Thyroid Gland - thyroxine (growth/metabolism)
• D. Hypothalamus - ADH (water reabsorption in
  kidney), oxytocin (milk release, uterine
  contract)
• E. Thymus - thymosin (white blood cells)
• F. Adrenal glands- corticoids (metabolism of
  protein, carb and fats)
• G. Pancreas - Insulin, Glucagon
• H. Ovaries - estrogen/progesteron
• I. Testes - testosterone

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Hormones chemical messengers in the body

• A, Made in glands, secreted (sent) into
  bloodstream
• B. Example Pituitary, thyroid, adrenal,
  ovaries, testes, pancreas

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Secreting cell a gland Blue circles hormone
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Hormones you need to know

• 1. Epinephrine
• 2. Glucagon
• 3. Insulin
• 4. Oxytocin
• 5. Antidiuretic hormone (ADH)

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Epinephrine (adrenaline)

• Made by gland adrenal glands
• Target tissue muscle, blood vessels
• Effect it has Initiates response to stress.
• Increases metabolic rate, heart rate and blood
  pressure
• dilates blood vessels
• raises blood sugar

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Oxytocin

• Made by gland pituitary gland
• Target tissue Uterus, mammary gland
• Effect it has
• Stimulate uterine contraction
• Release of milk

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ADH (antidiuretic hormone)

• Made by gland pituitary gland
• Target tissue Kidneys
• Effect it has
• Stimulates reabsorption of water (keeps water in
  the body)

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Glucagon

• Made by gland pancreas
• Target tissue liver, fatty tissues
• Effect it has
• raises blood sugar
• tells liver to turn its stored glycogen into
  glucose and to put it into the bloodstream

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Insulin

• Made by gland pancreas
• Target tissue all tissues
• Effect it has
• lowers blood sugar
• Changes glucose to glycogen

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Feedback process that allows the body to sense
changing internal conditions and respond to them

• A. Positive
• Definition Change toward initial conditions
• When does this happen? When some critical process
  must be completed quickly

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• Positive feedback.... the best example of this is
  during pregnancy. When a woman goes into labor
  the whole process is controlled by a positive
  feedback system. The uterus senses increased
  pressure and sends a message to the brain saying
  "woah.... too much pressure... need to get rid of
  it." The brain send a message (through a
  hormone.. oxytocin) back to the uterus which
  allows it to begin contracting. This system stays
  in effect until the pressure (baby) is expelled.
  In short, a positive feedback system is one where
  something is sensed somewhere in the body and the
  brain sends messgaes to that part to increase
  some action.

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• An example of beneficial positive feedback is
  seen in childbirth, where stretching of the
  uterus triggers the secretion of a hormone,
  oxytocin, which stimulates uterine contractions
  and speeds up labor. Yet another is seen in
  protein digestion, where the presence of
  partially digested protein in the stomach
  triggers the secretion of hydrochloric acid and
  pepsin, the enzyme that digests protein. Thus,
  once digestion begins, it becomes a
  self-accelerating process.

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• In the positive feedback loop, the body senses a
  change and activates mechanisms that accelerate
  or increase that change. This can also aid
  homeostasis, but in many cases it produces the
  opposite effect and can be life-threatening.An
  example of its beneficial effect is seen in blood
  clotting. Part of the complex biochemical pathway
  of clotting is the production of an enzyme that
  forms the matrix of the blood clot, but also
  speeds up the production of still more thrombin.
  That is, it has a self-catalytic,
  self-accelerating effect, so that once the
  clotting process begins, it runs faster and
  faster until, ideally, bleeding stops.

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Example of positive feedback

• Damage is done to a blood vessel
• Clotting fibers accumulate at the site of damage
• Clot formation triggers release of chemicals
• Chemicals stimulate the production of more
  clotting fibers
• Goes back to step 2

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Watch animation of blood clotting

• http//www.mhhe.com/biosci/esp/2002_general/Esp/fo
  lder_structure/tr/m1/s7/trm1s7_3.htm

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Negative Feedback

• Definition change away from initial conditions
• When does this happen? Corrects an abnormal
  situation

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Example of Negative Feedback

• Dehydration leads to low blood pressure
• Low blood pressure detected by baroreceptors on
  the heart
• Those baroreceptors send message to brain
• The brain sends a message to both the blood
  vessels and the heart
• Arteries constrict and heart rate increases
• Result Normal blood pressure

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Feedback Insulin and Glucagon

• If sugar gets above 100 mL, the pancreas makes
  insulin, which lowers blood sugar
• If sugar gets below 100 mL, the pancreas makes
  glucagon, which acts to raise the blood sugar

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• The usual means of maintaining homeostasis is a
  general mechanism called a negative feedback
  loop. The body senses an internal change and
  activates mechanisms that reverse, or negate,
  that change.An example of negative feedback is
  body temperature regulation. If blood temperature
  rises too high, this is sensed by specialized
  neurons in the hypothalamus of the brain. They
  signal other nerve centers, which in turn send
  signals to the blood vessels of the skin. As
  these blood vessels dilate, more blood flows
  close to the body surface and excess heat
  radiates from the body. If this is not enough to
  cool the body back to its set point, the brain
  activates sweating. Evaporation of sweat from the
  skin has a strong cooling effect, as we feel when
  we are sweaty and stand in front of a fan

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• Body temperature also requires careful
  homeostatic control. On a spring or fall day in a
  temperate climate, the outdoor Fahrenheit
  temperature may range from the thirties or
  forties at night to the eighties in the afternoon
  (a range of perhaps 4 to 27 degrees Celsius). In
  spite of this environmental fluctuation, our core
  body temperature is normally 37.2 to 37.6 degrees
  Celsius (99.0 to 99.7 degrees Fahrenheit) and
  fluctuates by only 1 degree or so over the course
  of 24 hours. Indeed, if core body temperatures
  goes below 33 degrees Celsius (91 degrees
  Fahrenheit) a person is likely to die of
  hypothermia, and if it goes above 42 degrees
  Celsius (108 degrees Fahrenheit), death from
  hyperthermia is likely.