Transcript lecture presentations

Trouble brewing?
Trouble brewing? 2 choices…
Trouble brewing? 2 choices…
OR
Two systems coordinate communication
throughout the body: the endocrine system and the
nervous system
• The endocrine system secretes hormones that
coordinate slower but longer-acting responses
including reproduction, development, energy
metabolism, growth, and behavior
• The nervous system conveys high-speed
electrical signals along specialized cells called
neurons; these signals regulate other cells
© 2011 Pearson Education, Inc.
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.
Andre the Giant had acromegaly: HGH secreted in adulthood
To what would hyposecretion of HGH in childhood lead?
Glands of the endocrine system
Let’s review stuff we know…
What’s the difference?
• Endocrine
• Paracrine
• Autocrine
Methods of
intercellular
communication by
secreted molecules
Blood
vessel
Response
(a) Endocrine signaling
Response
(b) Paracrine signaling – short distances
Response
(c) Autocrine signaling – short distances
Synapse
Neuron
Response
(d) Synaptic signaling
Neurosecretory
cell
Blood
vessel
(e) Neuroendocrine signaling
Response
What’s the difference?
• Endocrine
• Exocrine
How do they work differently?
• Protein
• Steroid
Synaptic and Neuroendocrine Signaling
• In synaptic signaling, neurons form specialized
junctions with target cells, called synapses
• At synapses, neurons secrete molecules called
neurotransmitters that diffuse short distances
and bind to receptors on target cells
• In neuroendocrine signaling, specialized
neurosecretory cells secrete molecules called
neurohormones that travel to target cells via the
bloodstream
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Signaling by Pheromones, hormones
outside the self
• Pheromones serve many functions, including:
 marking trails leading to food, defining territories,
warning of predators, and attracting potential mates
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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)
3 Chemical
classes of
hormones
( or two )
Water-soluble (hydrophilic)
Lipid-soluble (hydrophobic)
Polypeptides
Steroids
0.8 nm
Insulin
Cortisol
Amines
Epinephrine
Thyroxine
Example
Pathway
A simple
endocrine
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
Example
Pathway

A simple
neuroendocrine
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
SECRETORY
CELL
Lipidsoluble
hormone
Watersoluble
hormone
Receptor location
varies with hormone
type.
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
Animation: Water-Soluble Hormone
Right-click slide / select”Play”
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Figure 45.7-1 Epinephrine (aka) adrenaline,
has multiple effects
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
Animation: Lipid-Soluble Hormone
Right-click slide / select”Play”
© 2011 Pearson Education, Inc.
Hormone
(estradiol)
Steroid
hormone
receptors
directly
regulate
gene
expression
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 for two reasons:
© 2011 Pearson Education, Inc.
Multiple Effects of Hormones
• The same hormone may have different effects on
target cells that have for two reasons:
1. Different receptors for the hormone
2. Different signal transduction pathways
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One
hormone,
different
effects
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
Multiple Effects of Hormones
• The same hormone may have different effects on
target cells that have for two reasons:
1. Different receptors for the hormone
2. Different signal transduction pathways
Also……
3. Perception of physical
response
e.g. “Love on a bridge study”
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What functions hormones control…
Figure 45.1What signals caused this butterfly to grow within the body of a caterpillar?
Brain
Neurosecretory cells
Regulation of insect development
and metamorphosis
Corpora cardiaca
Corpora allata
PTTH
Prothoracic
gland
Juvenile
hormone (JH)
Ecdysteroid
EARLY
LARVA
Brain
Regulation of insect
development requires
multiple hormones
Neurosecretory cells
Corpora cardiaca
Corpora allata
PTTH
Prothoracic
gland
Juvenile
hormone (JH)
Ecdysteroid
EARLY
LARVA
LATER
LARVA
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
Maintenance of glucose homeostasis is done by paired hormones, insulin and
glucagon
Insulin
Beta cells of
pancreas
release insulin
into the blood.
STIMULUS:
Blood glucose level rises
(for instance, after eating a
carbohydrate-rich meal).
Homeostasis:
Blood glucose level
(70–110 mg/100 mL)
Figure 45.13a-2
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/100 mL)
Figure 45.13b-1
Homeostasis:
Blood glucose level
(70–110 mg/100 mL)
STIMULUS:
Blood glucose level
falls (for instance, after
skipping a meal).
Alpha cells of pancreas
release glucagon into
the blood.
Glucagon
Figure 45.13b-2
Homeostasis:
Blood glucose level
(70–110 mg/100 mL)
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
Diabetes Mellitus
• Diabetes mellitus is perhaps the best-known
endocrine disorder
• It is caused by a deficiency of insulin or a
decreased response to insulin in target tissues
• It is marked by elevated blood glucose levels
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• Type 1 diabetes mellitus (insulin-dependent) is an
autoimmune disorder in which the immune
system destroys pancreatic beta cells
• Type 2 diabetes mellitus (non-insulin-dependent)
involves insulin deficiency or reduced response of
target cells due to change in insulin receptors
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45.3 Coordination of Endocrine and
Nervous Systems in Vertebrates
• The hypothalamus receives information from the
nervous system and initiates responses through
the endocrine system
• Attached to the hypothalamus is the pituitary
gland, composed of the posterior pituitary and
anterior pituitary
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Figure 45.14
Cerebrum
Pineal
gland
Thalamus
Hypothalamus
Cerebellum
Pituitary
gland
Spinal cord
• The posterior pituitary
stores and secretes
hormones that are
made in the
hypothalamus
• The anterior pituitary
makes and releases
hormones under
regulation of the
hypothalamus
Hypothalamus
Posterior
pituitary
Anterior
pituitary
tropic hormones = target endocrine glands
hypothalamus
thyroid-stimulating
hormone
(TSH)
Thyroid gland
Adrenal
cortex
posterior antidiuretic
pituitary hormone
(ADH)
anterior
pituitary
gonadotropic
hormones:
folliclestimulating
hormone (FSH)
& luteinizing
hormone (LH)
Kidney
tubules
Muscles
of uterus
Melanocyte
in amphibian
Bone
and muscle
Testes
Ovaries
Mammary
glands
in mammals
Table 45.1a
Table 45.1b
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
hormone cascade pathway
• The release of thyroid 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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Example
Pathway
Stimulus
Cold
Sensory neuron

A
hormone
cascade
pathway
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
Evolution of Hormone Function
• Over the course of evolution the function of a
given hormone may diverge 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
resorption of the tadpole tail during metamorphosis
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Hormones as homologous structures
What does this tell you about these hormones?
How could these hormones have different effects?
same gene family
gene duplication?
prolactin
mammals
milk
production
birds
fat
metabolism
fish
amphibians
salt &
water
balance
metamorphosis
& maturation
growth
hormone
growth
& development
• Melanocyte-stimulating hormone (MSH)
regulates skin color in amphibians, fish, and
reptiles by controlling pigment distribution in
melanocytes
• In mammals, MSH plays additional roles in
hunger and metabolism in addition to
coloration
© 2011 Pearson Education, Inc.
The roles of parathyroid hormone (PTH) in regulating blood calcium
levels in mammals.
PTH
Parathyroid
gland (behind
thyroid)
STIMULUS:
Falling blood
Ca2 level
Homeostasis:
Blood Ca2 level
(about 10 mg/100 mL)
Figure 45.20-2
Increases Ca2
uptake in
intestines
Active
vitamin D
Stimulates Ca2
uptake in kidneys
PTH
Stimulates
Ca2 release
from bones
Parathyroid
gland (behind
thyroid)
STIMULUS:
Falling blood
Ca2 level
Blood Ca2
level rises.
Homeostasis:
Blood Ca2 level
(about 10 mg/100 mL)
Multiple hormonal pathways/effects during “fight or flight”
• Epinephrine and norepinephrine
– Trigger the release of glucose and fatty acids
into the blood
– Increase oxygen delivery to body cells
– Direct blood toward heart, brain, and skeletal
muscles and away from skin, digestive system,
and kidneys
• The release of epinephrine and norepinephrine
occurs in response to involuntary nerve signals
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Effects of stress on a body
Stress
Nerve
Spinal cord
signals
(cross section)
Hypothalamus
Releasing
hormone
Nerve
cell
Anterior pituitary
Blood vessel
adrenal medulla
secretes epinephrine
& norepinephrine
Nerve cell
ACTH
Adrenal
gland
Adrenal cortex
secretes
mineralocorticoids
& glucocorticoids
Kidney
(A) SHORT-TERM STRESS RESPONSE
Effects of epinephrine and norepinephrine:
1. Glycogen broken down to glucose;
increased blood glucose
2. Increased blood pressure
3. Increased breathing rate
4. Increased metabolic rate
5. Change in blood flow patterns, leading
to increased alertness & decreased
digestive & kidney activity
(B) LONG-TERM STRESS RESPONSE
Effects of
mineralocorticoids:
Effects of
glucocorticoids:
1. Retention of
sodium ions &
water by kidneys
1. Proteins & fats broken
down & converted to
glucose, leading to
increased blood
glucose
2. Increased blood
volume & blood
pressure
2. Immune system
suppressed
Figure 45.21
(b) Long-term stress response
and the adrenal cortex
(a) Short-term stress response
and the adrenal medulla
Stress
Spinal cord
(cross section)
Hypothalamus
Nerve
signals
Releasing
hormone
Nerve
cell
Anterior pituitary
Blood vessel
Adrenal medulla
secretes epinephrine
and norepinephrine.
Nerve cell
ACTH
Adrenal cortex
secretes mineralocorticoids and
glucocorticoids.
Adrenal
gland
Kidney
Effects of epinephrine and norepinephrine:
• Glycogen broken down to glucose;
increased blood glucose
• Increased blood pressure
• Increased breathing rate
• Increased metabolic rate
• Change in blood flow patterns, leading to
increased alertness and decreased digestive,
excretory, and reproductive system activity
Effects of
mineralocorticoids:
Effects of
glucocorticoids:
• Retention of sodium
ions and water by
kidneys
• Proteins and fats broken
down and converted to
glucose, leading to
increased blood glucose
• Increased blood
volume and blood
pressure
• Partial suppression of
immune system
• Glucocorticoids, such as cortisol, influence
glucose metabolism and the immune system
• Mineralocorticoids, such as aldosterone, affect
salt and water balance
• The adrenal cortex also produces small amounts
of steroid hormones that function as sex
hormones
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Sex Hormones
• The gonads, testes and ovaries, produce most of
the sex hormones: androgens, estrogens, and
progestins
• All three sex hormones are found in both males
and females, but in significantly different
proportions
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• The testes primarily synthesize androgens,
mainly testosterone, which stimulate
development and maintenance of the male
reproductive system
– Testosterone causes an increase in muscle and bone
mass and is often taken as a supplement to cause
muscle growth, which carries health risks
– It has been suggested by some scientists that the ratio of two digits in
particular, the 2nd (index finger) and 4th (ring finger), is affected by
exposure to testosterone (androgens) in the uterus
– Low 2D:4D is positively correlated with success in sport
– Discovery article about ratio outcomes
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What role do hormones play in
making a mammal male or female?
RESULTS
Appearance of Genitalia
Chromosome Set
No surgery
Embryonic gonad
removed
XY (male)
Male
Female
XX (female)
Female
Female
Melatonin and Biorhythms
• The pineal gland, located in the brain, secretes
melatonin
• Light/dark cycles control release of melatonin
© 2011 Pearson Education, Inc.
Did you know?…
• One reason that kittens sleep so much is because a
growth hormone is released only during sleep.
• The levels of two stress hormones, cortisol and
epinephrine which suppress the body's immune
system, will actually drop after a dose of laughter.
• Chocolate is associated with the release of serotonin,
the hormone that makes you feel relaxed, calm, and
happy. So are hugs.