Transcript APEndocrinologyStudentNotesm

ENDOCRINE SYSTEM
Glands, Hormones, and intercellular
communication
WHAT IS A HORMONE?

Similar, sometimes identical substances that
have a similar mechanism of action wherever
they’re produced.
WHY ARE HORMONES IMPORTANT?
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Regulate Homeostasis
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Keeps everything balanced
Regulate function of other
body systems
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i.e. structural/skeletal
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i.e. digestive system
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Bone formation
metabolism
i.e. reproductive system
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menstrual cycle
HOW DO HORMONES WORK ANYWAY?
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Endogenous substance
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Made by a cell or gland
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Travels to target cells via
the bloodstream
Enter the cell by
endocytosis or…
 Binds and initiates a
response
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Sonic Hedgehog
“faster than the
naked eye!”
WHAT ARE SOME CAUSES OF
HORMONE IMBALANCE?
Dude looks
like a lady!
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Genetic:
Genes may not function
 Proteins may not be
synthesized correctly
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Ex. Myostatin Protein
 Ex. Collagen Production
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MY, OH MY, OH MYOSTATIN!
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I’ll have what
he’s havin!!!
Protein that inhibits muscle growth
Mighty Mouse!
THE DIFFERENCE BETWEEN THE
ENDOCRINE AND EXOCRINE SYSTEM
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Gland: Structure that synthesizes a product to be
exported from the cells.
Endocrine glands: NO DUCTS!
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Exocrine glands: DUCTS!
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i.e. sweat, oil for hair/skin
Move substances to a body organ or to the surface
LET’S MEET THE GLANDS THAT MAKE THE
MAGIC HAPPEN!
THE PITUITARY GLAND
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Posterior:
Oxytocin: Uterine Contractions
 Anti-Diuretic Hormone (ADH)
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Controls blood fluid volume
 Targets the kidneys
 More water is removed from urine
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Anterior:
Melanocyte stimulation
 growth hormone
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Growth
 Hypo= Dwarfism
 Hyper= GIGANTISM!
A QUICK STORY ABOUT LIFE, LOVE, AND
FROG PITUITARY GLANDS!
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Xenopus laevis
“The African Clawed Frog”
 Hypophysectomy
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THYROID GLAND: G. THYREOS=SHIELD
Affects almost every physiological process in your
body
 Looks like a butterfly landed on your windpipe
 2 lobes connected by isthmus
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Think “isthmus of Panama!”
THYROID CONTINUED:
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Main duties of the thyroid:
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Regulate cellular metabolism
Regulate cellular respiration
Rate cells use glucose
Rate of glycogen breakdown
Maintains 98.6
Regulate growth
Stimulate mental processes
THE LIST CONTINUES!
THYROID PROBLEMS
Hypothyroidism: Underproduction of thyroid hormone
Leads to Weight Gain
Hyperthyroidism: Overproduction of thyroid hormone
Leads to Weight Loss
Thyroid Cancer
Goiter
Hypothyroidism
INTERMISSION! LET’S RELAX A MINUTE!
ADRENAL GLAND

Located on top of
kidneys
“Ad”=
 “renal”=
 Produces Epinephrine
 a.k.a.
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Fight or Flight!
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What happens when
the fight or flight
response is activated?
MOOORTALLL COMMBAAAAAATT!!!
TEST YOUR MIGHT!
Saliva:
Skin:
Eyes:
Lungs:
Heart:
Bowel:
Stomach:
Blood Vessels:
Muscles:
TESTES/OVARIES
TESTOSTERONE
Testes produce estrogen
ESTROGEN
 Ovaries produce testosterone
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Both lead to development of
secondary sex characteristics
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HORMONE MANIPULATION:
REPLACEMENT THERAPY
Testosterone
 High Levels: Men
Estrogen
 High Levels: Women
Increased Sex Drive
 Increased Muscle Mass
Decreased Sex Drive
 Decreased Muscle Mass
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Low Levels: Men
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Low Levels: Women
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Hormone replacement therapy may be used to
combat these symptoms! OR . . . . It can do
other stuff!