Download Endocrine System

Endocrine: Chemical Messages
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Hormones coordinate activities in different
parts of the body
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regulate energy use, metabolism, and growth
also maintain homeostasis
Endocrine glands secrete hormones
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chemical signals that are carried by blood and
cause specific changes in target cells
Endocrine: vs Nervous
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Both communication but:
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Endocrine take longer for effect b/c needs to
be made and travels through blood stream
throughout body and causes protein synthesis
longer lasting because hormones can trigger
protein production that lasts long time
Endocrine: vs Exocrine
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No hormones – release chemicals through
ducts instead of hormones through blood
stream
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ex. Pancreas release enzymes into small
intestine via duct
Endocrine: Glands
Endocrine: Hormones
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Hormone released by
glands and travel
through bloodstream
to target cells
Target cells have
SPECIFIC receptors
Endocrine: Hormones
Protein vs Steroid
Endocrine: Hormones
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Proteins - Most hormones
are amino acids
bind to receptor proteins
in target-cell plasma
membrane
Initiate signaltransduction pathways,
cause changes inside
target cell
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Steroid hormones bind to
intracellular receptors
steroid-receptor complex
binds to DNA, turning
specific genes on or off
Desired outcome takes
longer than protein
hormone
Only the sex glands and
the adrenal cortex
secrete steroid hormone
Table 26.3
Table 26.3, part 2
Endocrine: Hypothalamus
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Hypothalamus - master control center of
the endocrine system
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Regulates posterior and anterior pituitary
gland
Endocrine: Pituitary Glands
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Both Pituitary Glands release when they
receive message from the Hypothalamus
Posterior Pituitary Glands: stores and
releases hormones made by hypothalamus
Anterior Pituitary Glands: makes own
hormones
Endocrine: Posterior Pituitary Gland
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Oxytocin
ADH: antidiuretic hormone
Endocrine: Anterior Pituitary Gland
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FLAT PEG
FSH: follicle
stimulating
LH: lutenizing
ACTH:
adrenocorticotropic
TSH: thyroid
stimulating
Prolactin
Endorphins
Growth Hormone
Endocrine: Negative Feedback
Mechanism
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Normal Negative
Feedback
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Abnormal (Goiter)
Endocrine: Thyroid
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Thyroid gland releases Thyroxine
Regulates development and metabolism
Endocrine: Regulating Calcium
Levels
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Calcitonin
Parathyroid
Hormone
Endocrine: Regulating Blood Sugar
Levels
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Insulin
Glucagon
Endocrine: Regulating Blood Sugar
Levels
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Blood glucose levels controlled by two
hormones secreted by pancreas
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Insulin: lowers blood sugar level
- signals cells to use and store glucose as
glycogen in liver
Glucagon: raises blood sugar level
- signals cells to release stored glycogen
from liver into blood
Endocrine: Diabetes
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Diabetes (2 types): body cells unable to absorb
glucose from blood
Type I (insulin-dependent) diabetes
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Autoimmune disease: pancreatic beta cells destroyed,
not enough insulin produced
Often develops before age 15
Patient requires insulin supplement, often by injection
Endocrine: Diabetes
Body cells unable to absorb glucose from
blood
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Type I (insulindependent) diabetes
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Autoimmune disease:
pancreatic beta cells
destroyed, not enough
insulin produced
Often develops before age
15
Patient requires insulin
supplement, often by
injection
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Type II (non-insulindependent) diabetes
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Pancreatic cells function
properly; sufficient
amounts of insulin
produced
Body cells fail to respond to
insulin
Accounts for 90% of
diabetes cases in the
United States
Associated with obesity
Often develops after age
40
Endocrine: Stress Hormones
(Adrenal Gland)
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Adrenal gland hormones - maintain
homeostasis when body under stress
Adrenal Medulla: Short Term Stress
Adrenal Cortex: Long Term Stress
Endocrine: Stress Hormones
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Adrenal medulla
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Nervous signals from
hypothalamus
stimulate secretion of
epinephrine and
norepinephrine
Trigger quickly fight or
flight response
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Adrenal cortex
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Chemical signals
(ACTH) stimulate
secretion of
corticosteroids
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glucocorticoids and
mineralocorticoids
Corticosteroids boost
blood pressure and
energy in response to
long-term stress
Stimulates ADH
production
Endocrine: Stress Hormones
(Adrenal Glands)
Endocrine: Stress Hormones
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Athletes often take
glucocorticoids
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Relieve pain and
inflammation
But they also mask
injury and suppress
immunity
Example: cortisone
Endocrine: Sex Hormones
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Gonads – secrete sex hormones (steroid
hormones)
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Secretion controlled by hypothalamus and pituitary
Steroid hormones found in both sexes but in
different proportions
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estrogens
progestins
androgens
Endocrine: Sex Hormones
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Estrogen and
progestins
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maintain the female
reproductive system
stimulate the
development of female
characteristics
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Androgens, such as
testosterone,
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trigger the
development of male
characteristics
In male elephant
seals, androgens
account for
bodies weighing 2 tons
or more, a thick hide,
and aggressive
behavior