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Endocrine System 15.3 Metabolism Bio 30
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Case Study: Andre the Giant
What condition does Andre have?
In what ways, does it affect his life?
Daily life?
Health?
Lifespan?
Emotional Effects?
What is the treatment for this condition?
https://www.youtube.com/watch?v=nj ZBYfNpWoE
+ A story about a man…
Robert Wadlow
http://en.wikipedia.org/wiki/Robert_W adlow
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Growth Hormone (hGH)
Produced
by anterior pituitary
Stimulates
skeleton
Problems
elongation of
with levels: Hyposecretion: Too little hGH – dwarfism Hypersecretion: Too much hGH – gigantism (if high only as child) Too much hGH – acromegaly (if high as adult)
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Human Growth Hormone (hGH) Excessive
amounts during adulthood leads to acromegaly (hypersecretion) Bones begin to widen since plates have already fused and cannot grow in length
Untreated: Cardiovascular disease Sugar intolerance (diabetes) Muscle weakness Colon cancer Breathing problems
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hGH
increases cell size (hypertrophy) and connective tissues by promoting synthesis while inhibiting protein degradation or breakdown. Hyperplasia- increasing the number of cells
As
a person ages, hGH declines and cellular repair and protein replacement are compromised. As one ages, protein is replaced by fat, causing changes in the body’s shape
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This is clearly a problem… Your
body is trying to achieve a balance, a homeostasis
Page
471
Look
at the four graphs.
What
conclusions can you draw?
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This is clearly a problem… Endocrine
system’s main job is to maintain a
balanced internal environment Deviations
from the normal condition are USUALLY corrected
What
are some examples? (try balancing with your eyes closed)
Examples: The body works best at: a temperature of 37°C 0.1% blood glucose blood pH of 7.35
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How does the body prevent things from going out of control? Control Three
mechanisms
parts: Receptors, modulator (coordinating center), and effectors
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Homeostatic
control mechanisms can be divided into 2 groups: 1. Negative 2. Positive Read pg 472
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Negative
: most common, an imbalance causes a corrective action to restore body to its original state Ex: body temperature (furnace), hormones
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Positive
: process by which a small effect is amplified, it perpetuates itself Ex: fever, hormones released by mother when a baby suckles
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It’s game time!
Using your cue cards decide whether each of the following systems is an example of positive or negative
You will get a 30 second discussion period before you must “play your card”!
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Negative or Positive ?
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Negative or Positive ?
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Negative or Positive ?
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Negative or Positive ?
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Negative or Positive ?
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Negative or Positive ?
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Negative or Positive ?
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Negative or Positive ?
+ How are hormones controlled? Loops Hormone production must have a turn-off switch
If
hormones are not shut off, they can have serious health problems
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Negative Loop Hypothalamus,
anterior pituitary (release hGH), liver (releases growth factors), stimulate muscle, bone and fat cells
Let’s
Draw It!
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Practice Questions:
1. Define homeostasis in your own words.
2. Use the example of a thermostat to explain homeostasis. 3. Think of an example of a positive and a negative loop in everyday life.