Download AP Biology Chapter 45 Endocrine System Guided Notes

LECTURE PRESENTATIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 45
Hormones and the Endocrine
System
Lectures by
Erin Barley
Kathleen Fitzpatrick
© 2011 Pearson Education, Inc.
Overview: The Body’s Long-Distance
Regulators
• Animal _______________ are chemical signals
that are secreted into the circulatory system and
communicate regulatory messages within the
body
• Hormones reach ____________ of the body, but
only target cells have ________ for that hormone
• Insect metamorphosis is regulated by hormones
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• Two systems coordinate communication
throughout the body: the endocrine system and
the nervous system
• The __________________ secretes hormones
that coordinate slower but longer-acting
responses including reproduction, development,
energy metabolism, growth, and behavior
• The ________________ conveys high-speed
electrical signals along specialized cells called
neurons; these signals regulate other cells
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Concept 45.1: Hormones and other
signaling molecules bind to target receptors,
triggering specific response pathways
• ________________ is just one of several ways
that information is transmitted between animal
cells
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Intercellular Communication
• The ways that signals are transmitted between
animal cells are classified by two criteria
– The _______________
– The ___________________ by the signal in
reaching its target
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Endocrine Signaling
• Hormones secreted into extracellular fluids by
endocrine cells reach their targets via the
______________________________
• Endocrine signaling maintains _____________,
mediates _______________, regulates ______
______________________
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Figure 45.2
Blood
vessel
Response
(a) Endocrine signaling
Response
(b) Paracrine signaling
Response
(c) Autocrine signaling
Synapse
Neuron
Response
(d) Synaptic signaling
Neurosecretory
cell
Blood
vessel
(e) Neuroendocrine signaling
Response
Paracrine and Autocrine Signaling
• _________________ are molecules that act over
short distances, reaching target cells solely by
diffusion
• In __________________, the target cells lie near
the secreting cells
• In __________________, the target cell is also
the secreting cell
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Figure 45.2a
Blood
vessel
Response
(a) Endocrine signaling
Response
(b) Paracrine signaling
Response
(c) Autocrine signaling
Synaptic and Neuroendocrine Signaling
• In________________, neurons form specialized
junctions with target cells, called synapses
• At synapses, neurons secrete molecules called
______________ that diffuse short distances
and bind to receptors on target cells
• In neuroendocrine signaling, specialized
neurosecretory cells secrete molecules called
___________________ that travel to target cells
via the bloodstream
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Figure 45.2b
Synapse
Neuron
Response
(d) Synaptic signaling
Neurosecretory
cell
Blood
vessel
(e) Neuroendocrine signaling
Response
Signaling by Pheromones
• Members of the same animal species sometimes
communicate with________________, chemicals
that are released into the environment
• Pheromones serve many functions, including
marking trails leading to food, defining
territories, warning of predators, and
attracting potential mates
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Endocrine Tissues and Organs
• In some tissues, endocrine cells are grouped
together in ductless organs called ____________
_______________
• Endocrine glands secrete ______________
directly into surrounding fluid
• These contrast with _______________, which
have ducts and which secrete substances onto
body surfaces or into cavities
– Ex. Salivary glands
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Figure 45.4
Major endocrine glands:
Hypothalamus
Pineal gland
Pituitary gland
Thyroid gland
Parathyroid glands
(behind thyroid)
Organs containing
endocrine cells:
Thymus
Heart
Liver
Adrenal glands
(atop kidneys)
Stomach
Pancreas
Kidneys
Ovaries (female)
Small
intestine
Testes (male)
Chemical Classes of Hormones
• Three major classes of molecules function as
hormones in vertebrates
– __________________ (proteins and peptides)
– _________________ derived from amino acids
– ____________________
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• _______________hormones (steroid hormones)
pass easily through cell membranes, while
__________________hormones (polypeptides
and amines) do not
• The solubility of a hormone correlates with the
location of ______________ inside or on the
surface of target cells
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Figure 45.5
Water-soluble (hydrophilic)
Lipid-soluble (hydrophobic)
Polypeptides
Steroids
0.8 nm
Insulin
Cortisol
Amines
Epinephrine
Thyroxine
Cellular Response Pathways
• Water- and lipid-soluble hormones differ in their
____________ through a body
• Water-soluble hormones are secreted by
______________, travel freely in the
bloodstream, and bind to ___________________
• Lipid-soluble hormones ___________across cell
membranes, travel in the bloodstream bound to
transport proteins, and diffuse through the
membrane of target cells
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Figure 45.6-1
SECRETORY
CELL
Lipidsoluble
hormone
Watersoluble
hormone
VIA
BLOOD
Signal receptor
Transport
protein
TARGET
CELL
Signal
receptor
NUCLEUS
(a)
(b)
Figure 45.6-2
SECRETORY
CELL
Lipidsoluble
hormone
Watersoluble
hormone
VIA
BLOOD
Signal receptor
TARGET
CELL
Cytoplasmic
response
Transport
protein
OR
Gene
regulation
Signal
receptor
Cytoplasmic
response
NUCLEUS
(a)
(b)
Gene
regulation
Pathway for Water-Soluble Hormones
• Binding of a hormone to its receptor initiates a
________________ pathway leading to
responses in the cytoplasm, enzyme activation,
or a change in gene expression
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• The hormone ____________ has multiple effects
in mediating the body’s response to short-term
stress
• Epinephrine binds to receptors on the plasma
membrane of _____________ cells
• This triggers the release of messenger
molecules that activate enzymes and result in
the release of ___________ into the bloodstream
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Figure 45.7-1
Epinephrine
Adenylyl
cyclase
G protein
G protein-coupled
receptor
GTP
ATP
cAMP
Second
messenger
Figure 45.7-2
Epinephrine
Adenylyl
cyclase
G protein
G protein-coupled
receptor
GTP
ATP
cAMP
Inhibition of
glycogen synthesis
Promotion of
glycogen breakdown
Protein
kinase A
Second
messenger
Pathway for Lipid-Soluble Hormones
• The response to a lipid-soluble hormone is
usually a change in ______________________
• ________________ hormones, and the hormonal
form of ___________enter target cells and bind
to protein receptors in the cytoplasm or nucleus
• Protein-receptor complexes then act as
___________________ in the nucleus, regulating
transcription of specific genes
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Figure 45.8-1
Hormone
(estradiol)
Estradiol
(estrogen)
receptor
EXTRACELLULAR
FLUID
Plasma
membrane
Hormone-receptor
complex
Figure 45.8-2
EXTRACELLULAR
FLUID
Hormone
(estradiol)
Estradiol
(estrogen)
receptor
Plasma
membrane
Hormone-receptor
complex
NUCLEUS
CYTOPLASM
DNA
Vitellogenin
mRNA
for vitellogenin
Multiple Effects of Hormones
• The same hormone may have different effects on
target cells that have
– Different ______________ for the hormone
– Different ______________________________
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Figure 45.9
Same receptors but different
Different receptors
intracellular proteins (not shown)
Different cellular
responses
Different cellular
responses
Epinephrine
Epinephrine
Epinephrine
 receptor
 receptor
 receptor
Glycogen
deposits
Glycogen
breaks down
and glucose
is released
from cell.
(a) Liver cell
Vessel
dilates.
(b) Skeletal muscle
blood vessel
Vessel
constricts.
(c) Intestinal blood
vessel
Signaling by Local Regulators
• _________________ are secreted molecules that
link neighboring cells or directly regulate the
secreting cell
• Types of local regulators
– ______________ and ________________
– __________________
– __________________
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• In the immune system, prostaglandins promote
__________ and ______________ and intensify
the sensation of pain
• Prostaglandins help regulate _______________
_______________, an early step in formation of
blood clots
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Coordination of Neuroendocrine and
Endocrine Signaling
• The endocrine and nervous systems generally
act __________________ to control reproduction
and development
• For example, in larvae of butterflies and moths,
the signals that direct molting originate in the
brain
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• In insects, molting and development are
controlled by a combination of hormones
– A _____________(PTTH) stimulates release of
________________from the prothoracic glands
– _______________________ promotes retention
of larval characteristics
– _______________________ promotes molting
(in the presence of juvenile hormone) and
development (in the absence of juvenile
hormone) of adult characteristics
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Figure 45.10-3
Brain
Neurosecretory cells
Corpora cardiaca
Corpora allata
PTTH
Prothoracic
gland
Juvenile
hormone (JH)
Low
JH
Ecdysteroid
EARLY
LARVA
LATER
LARVA
PUPA
ADULT
Concept 45.2: Feedback regulation and
antagonistic hormone pairs are common
in endocrine systems
• Hormones are assembled into _____________
_______________________
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Simple Hormone Pathways
• Hormones are released from an endocrine cell,
travel through the bloodstream, and interact with
specific receptors within a target cell to cause a
__________________ response
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• For example, the release of acidic contents of the
stomach into the duodenum stimulates endocrine
cells there to secrete _________________
• This causes target cells in the _____________, a
gland behind the stomach, to raise the pH in the
duodenum
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Figure 45.11
Example
Pathway
Negative feedback

Low pH in
duodenum
Stimulus
Endocrine
cell
S cells of duodenum
secrete the hormone
secretin ( ).
Hormone
Target
cells
Response
Blood
vessel
Pancreas
Bicarbonate release
• In a simple neuroendocrine pathway, the stimulus
is received by a sensory neuron, which stimulates
a __________________ cell
• The neurosecretory cell secretes a
__________________________, which enters
the bloodstream and travels to target cells
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Figure 45.12
Example
Pathway

Stimulus
Suckling
Sensory
neuron
Positive feedback
Hypothalamus/
posterior pituitary
Neurosecretory cell Posterior pituitary
secretes the
neurohormone
Neurohormone
oxytocin ( ).
Blood vessel
Target
cells
Response
Smooth muscle in
breasts
Milk release
Feedback Regulation
• A _________________ loop inhibits a response
by reducing the initial stimulus, thus preventing
excessive pathway activity
• ___________________ reinforces a stimulus to
produce an even greater response
• For example, in mammals ____________ causes
the release of milk, causing greater suckling by
offspring, which stimulates the release of more
oxytocin
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Insulin and Glucagon: Control of Blood
Glucose
• _____________ (decreases blood glucose) and
_____________ (increases blood glucose) are
antagonistic hormones that help maintain glucose
homeostasis
• The pancreas has clusters of endocrine cells
called ______________ with _________ cells
that produce glucagon and __________ cells that
produce insulin
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Figure 45.13
Insulin
Body cells
take up more
glucose.
Blood glucose
level declines.
Beta cells of
pancreas
release insulin
into the blood.
Liver takes
up glucose
and stores it
as glycogen.
STIMULUS:
Blood glucose level rises
(for instance, after eating a
carbohydrate-rich meal).
Homeostasis:
Blood glucose level
(70–110 mg/m100mL)
STIMULUS:
Blood glucose level
falls (for instance, after
skipping a meal).
Blood glucose
level rises.
Liver breaks
down glycogen
and releases
glucose into
the blood.
Alpha cells of pancreas
release glucagon into
the blood.
Glucagon
Target Tissues for Insulin and Glucagon
• Insulin ___________blood glucose levels by
– Promoting the ________________________
– Slowing _____________________ in the liver
– Promoting ______________, not breakdown
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• Glucagon ___________ blood glucose levels by
– Stimulating conversion of ___________ to
__________________ in the liver
– Stimulating breakdown of _______and _______
into glucose
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Diabetes Mellitus
• __________________ is perhaps the bestknown endocrine disorder
• It is caused by a deficiency of __________ or a
_________________ to insulin in target tissues
• It is marked by __________blood glucose levels
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• _____________________ (insulin-dependent) is
an autoimmune disorder in which the immune
system destroys pancreatic ________cells
• ____________________(non-insulin-dependent)
involves insulin deficiency or reduced response of
target cells due to change in insulin receptors
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Concept 45.3: The hypothalamus and
pituitary are central to endocrine regulation
• Endocrine pathways are subject to regulation by
the_______________, including the brain
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Coordination of Endocrine and Nervous
Systems in Vertebrates
• The _________________ receives information
from the nervous system and initiates responses
through the endocrine system
• Attached to the hypothalamus is the __________
________________, composed of the posterior
pituitary and anterior pituitary
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• The __________________ stores and secretes
hormones that are made in the hypothalamus
• The __________________ makes and releases
hormones under regulation of the hypothalamus
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Figure 45.14
Cerebrum
Pineal
gland
Thalamus
Hypothalamus
Cerebellum
Pituitary
gland
Spinal cord
Hypothalamus
Posterior
pituitary
Anterior
pituitary
Posterior Pituitary Hormones
• The two hormones released from the posterior
pituitary act directly on nonendocrine tissues
– _______________ regulates milk secretion by
the mammary glands
– _____________________ regulates physiology
and behavior
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Figure 45.15
Hypothalamus
Neurosecretory
cells of the
hypothalamus
Neurohormone
Axons
Posterior
pituitary
Anterior
pituitary
HORMONE
ADH
Oxytocin
TARGET
Kidney
tubules
Mammary glands,
uterine muscles
Anterior Pituitary Hormones
• Hormone production in the _______________ is
controlled by releasing and inhibiting hormones
from the hypothalamus
• For example, prolactin-releasing hormone from
the hypothalamus stimulates the anterior pituitary
to secrete ___________________, which has a
role in milk production
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Figure 45.16
Tropic effects only:
FSH
LH
TSH
ACTH
Neurosecretory
cells of the
hypothalamus
Nontropic effects only:
Prolactin
MSH
Nontropic and tropic effects:
GH
Hypothalamic
releasing and
inhibiting
hormones
Portal vessels
Endocrine cells
of the anterior
pituitary
Pituitary
hormones
Posterior
pituitary
HORMONE
FSH and LH
TSH
ACTH
Prolactin
TARGET
Testes or
ovaries
Thyroid
Adrenal
cortex
Mammary
glands
MSH
GH
Melanocytes Liver, bones,
other tissues
Table 45.1
Thyroid Regulation: A Hormone Cascade
Pathway
• A hormone can stimulate the release of a series
of other hormones, the last of which activates a
nonendocrine target cell; this is called a
_______________________________
• The release of ______________hormone results
from a hormone cascade pathway involving the
hypothalamus, anterior pituitary, and thyroid
gland
• Hormone cascade pathways typically involve
negative feedback
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Figure 45.17
Example
Pathway
Stimulus
Cold
Sensory neuron

Hypothalamus
Neurosecretory cell
Hypothalamus secretes
thyrotropin-releasing
hormone (TRH ).
Releasing hormone
Blood vessel
Negative feedback

Anterior pituitary
Tropic hormone
Endocrine cell
Anterior pituitary secretes
thyroid-stimulating
hormone (TSH, also known
as thyrotropin ).
Thyroid gland secretes
thyroid hormone
(T3 and T4 ).
Hormone
Target
cells
Response
Body tissues
Increased cellular
metabolism
Disorders of Thyroid Function and
Regulation
• _________________, too little thyroid function,
can produce symptoms such as
– Weight gain, lethargy, cold intolerance
• __________________, excessive production
of thyroid hormone, can lead to
– High temperature, sweating, weight loss,
irritability, and high blood pressure
• __________________can alter thyroid function
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• ____________disease, a form of
hyperthyroidism caused by autoimmunity, is
typified by protruding eyes
• Thyroid hormone refers to a pair of hormones
– _________________, with three iodine atoms
– _________________, with four iodine atoms
• Insufficient dietary ____________ leads to an
enlarged thyroid gland, called a ___________
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Evolution of Hormone Function
• Over the course of evolution the function of a
given hormone may _______ between species
• For example, thyroid hormone plays a role in
metabolism across many lineages, but in frogs
has taken on a unique function: stimulating the
_______________ of the tadpole tail during
metamorphosis
• ______________ also has a broad range of
activities in vertebrates
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• _____________________________________
regulates skin color in amphibians, fish, and
reptiles by controlling pigment distribution in
melanocytes
• In mammals, MSH plays additional roles in
__________ and _______________ in addition
to coloration
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Tropic and Nontropic Hormones
• A ________ hormone regulates the function of
endocrine cells or glands
• Three primarily tropic hormones are
– __________________________
– __________________________
– _______________________________
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• __________________ is secreted by the anterior
pituitary gland and has tropic and nontropic
actions
• It promotes growth directly and has diverse
metabolic effects
• It stimulates production of growth factors
• An excess of GH can cause ______________,
while a lack of GH can cause dwarfism
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