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Biology, Seventh Edition
Solomon • Berg • Martin
Chapter 47
Endocrine Regulation
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• The endocrine system
• Endocrine glands, cells, and
tissues that secrete hormones
–Hormones are an important type of
chemical signal by which cells
communicate
–Secreted into the interstitial fluid and
typically transported by the blood
–Bind with receptors or in specific
target cells
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Some types of endocrine signaling
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Four main chemical groups
• Fatty acid derivatives
–Prostaglandins and the juvenile
hormone of insects
• Steroids
–Secreted by the adrenal cortex, ovary,
and testis, as well as the molting
hormone of insects
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Four main chemical groups, cont.
• Amino acid derivatives
–Thyroid hormones and epinephrine
• Peptides or proteins
–ADH and glucagon are peptide
hormones
–Insulin is a small protein
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Major
chemical
groups of
hormones
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Hormone secretion
• Typically regulated by negative
feedback mechanisms
–Hormone is released in response to
some change in a steady state
–Triggers a response that counteracts
the changed condition
–This process restores homeostasis
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Regulation by negative feedback
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Steroid and thyroid hormones
• Hydrophic molecules
–Pass through the plasma membrane
–Combine with receptors within the
target cell
–The hormone-receptor complex may
activate or repress transcription of
messenger RNA coding for specific
proteins
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Mechanism of action of steroid hormones
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Peptide hormones are
hydrophillic and do not enter
target cells
• Combine with receptors on the
plasma membrane of target cells
• Many hormones bind to G proteinlinked receptors
–Act via signal transduction
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Overview of peptide hormone action
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Mechanism
of action of
hormones
that use G
protein-linked
receptors and
second
messengers
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Most peptide hormones are first
messengers
• Carry out their actions by way of
second messengers
–Cyclic AMP (cAMP)
–Calcium ions
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Phospholipid
products as
second
messengers
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Inositol trisphosphat (IP3) and
diacylglycerol (DAG)
• Second messengers that
–Increase calcium concentration
–Activate enzymes
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Receptor tyrosine kinases
• Enzyme-lined receptors
• Bind growth factors, including
insulin and nerve growth factors
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Signal amplification
• Occurs as each hormone-receptor
complex stimulates the production
of second messenger molecules
• Second messengers activate
protein kinase molecules that
activate protein molecules
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Four functions of hormones in
invertebrates
• Neurohormones secreted by
neurons rather than endocrine
glands
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Four functions of hormones in
invertebrates, cont.
• Help regulate
–Metabolism
–Growth and development
–Regeneration
–Molting
–Metamorphosis
–Reproduction and behavior
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Regulation of
growth and
molting in
insects
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Human endocrine
glands
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Some
endocrine
glands
and their
hormones
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Consequences of endocrine malfunction
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Nervous and endocrine
regulation
• Integrated in the hypothalamus,
which regulates the pituitary gland
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Oxytocin and ADH
• Produced by the hypothalamus
• Released by the posterior lobe of
the pituitary
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Hypothalamus
• Secretes
–Releasing hormones
–Inhibiting hormones
• These regulate the hormone output
of the anterior lobe of the pituitary
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Anterior lobe of the pituitary
• Secretes the growth hormone,
prolactin
• Several tropic hormones that
stimulate other endocrine glands
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
The
hypothalamus
regulates the
anterior lobe of
the pituitary
gland
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Growth hormone (GH)
• Anabolic hormone that stimulates
body growth
• Stimulates the liver to produce
insulin-like growth factors (IGFs),
which promote skeletal and tissue
growth
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Thyroid gland
• Secretes
–Thyroxine
–Triiodothyronine
• Stimulate the rate of metabolism
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Regulation of thyroid secretion
• Depends mainly on a negative
feedback system
–Anterior pituitary gland
–Thyroid gland
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Thyroid hyposecretion
• Childhood cretinism
• Adult myxedema
• Thyroid hypersecretion
• Most common cause is Grave’s
disease
• Goiter associated with both
hyposecretion and hypersecretion
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Regulation of
thyroid
secretion by
negative
feedback
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Parathyroid glands
• Secrete PTH
–Regulates calcium level in the blood
–Stimulates calcium release from
bones
• Calcitonin, secreted by the
thyroid, acts antagonistically to
PTH
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Regulation of calcium homeostasis by PTH
and calcitonin
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Islets of Langerhans
• Secrete insulin
–Stimulates cells to take up glucose
and so lowers blood glucose
• Secrete glucagon
–Raises blood glucose concentration
• Diabetes mellitus
–Results in decreased use of glucose
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Islets of Langerhans
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
• Adrenal glands
• Secrete hormones that help the
body cope with stress
• Adrenal medulla secretes
–Epinephrine
–Norepinephrine
• Adrenal cortex secretes
–Sex hormones
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Adrenal gland
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Biology, Seventh Edition
CHAPTER 47 Endocrine Regulation
Response
to stress
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