1. Trouble brewing?

2. Trouble brewing? 2 choices…

3. Trouble brewing? 2 choices…OR

4. 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
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5. Hormones and the Endocrine System
Chapter 45
Hormones and the Endocrine System

7. Andre the Giant had acromegaly: HGH secreted in adulthood
To what would hyposecretion of HGH in childhood lead?

8. Glands of the endocrine system

9. Let’s review stuff we know…

10. What’s the difference?
Endocrine
Paracrine
Autocrine

11. 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
Figure 45.2 Intercellular communication by secreted molecules.
Response
(d) Synaptic signaling
Neurosecretory cell
Blood vessel
Response
(e) Neuroendocrine signaling

12. What’s the difference?
Endocrine
Exocrine

13. How do they work differently?
Protein
Steroid

14. 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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15. 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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16. Major endocrine glands:
Figure 45.4
Major endocrine glands:
Hypothalamus
Pineal gland
Pituitary gland
Organs containing endocrine cells:
Thyroid gland
Thymus
Parathyroid glands (behind thyroid)
Heart
Liver
Adrenal glands (atop kidneys)
Stomach
Pancreas
Kidneys
Small intestine
Figure 45.4 Major human endocrine glands.
Ovaries (female)
Testes (male)

17. 3 Chemical classes of hormones ( or two )
Water-soluble (hydrophilic)
Lipid-soluble (hydrophobic)
Polypeptides
Steroids
0.8 nm
Insulin
Cortisol
Amines
Figure 45.5 Hormones differ in structure and solubility.
Epinephrine
Thyroxine

18. A simple endocrine pathway
Example
A simple endocrine pathway 
Stimulus
Low pH in duodenum
S cells of duodenum secrete the hormone secretin ( ).
Endocrine cell
Hormone
Negative feedback
Figure A simple endocrine pathway.
Blood vessel
Target cells
Pancreas
Response
Bicarbonate release

19. A simple neuroendocrine pathway
Example
A simple neuroendocrine pathway 
Stimulus
Suckling
Sensory neuron
Hypothalamus/ posterior pituitary
Posterior pituitary secretes the neurohormone oxytocin ( ).
Neurosecretory cell
Positive feedback
Neurohormone
Blood vessel
Figure A simple neuroendocrine pathway.
Target cells
Smooth muscle in breasts
Response
Milk release

20. Receptor location varies with hormone type.
SECRETORY CELL
Water- soluble hormone
Lipid- soluble hormone
VIA BLOOD
Transport protein
Signal receptor
TARGET CELL
Signal receptor
Figure 45.6 Receptor location varies with hormone type.
NUCLEUS
(a)
(b)

21. Water- soluble hormone Lipid- soluble hormone
Figure
SECRETORY CELL
Water- soluble hormone
Lipid- soluble hormone
VIA BLOOD
Transport protein
Signal receptor
TARGET CELL OR
Signal receptor
Figure 45.6 Receptor location varies with hormone type.
Cytoplasmic response
Gene regulation
Cytoplasmic response
Gene regulation
NUCLEUS
(a)
(b)

22. Animation: Water-Soluble Hormone Right-click slide / select”Play”
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23. Figure 45.7-1 Epinephrine (aka) adrenaline, has multiple effects
Adenylyl cyclase
G protein
G protein-coupled receptor
GTP
ATP
Second messenger
cAMP
Figure 45.7 Cell-surface hormone receptors trigger signal transduction.

24. G protein-coupled receptor GTP
Figure
Epinephrine
Adenylyl cyclase
G protein
G protein-coupled receptor
GTP
ATP
Second messenger
cAMP
Figure 45.7 Cell-surface hormone receptors trigger signal transduction.
Protein kinase A
Inhibition of glycogen synthesis
Promotion of glycogen breakdown

25. Animation: Lipid-Soluble Hormone Right-click slide / select”Play”
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26. Steroid hormone receptors directly regulate gene expression
Hormone (estradiol)
EXTRACELLULAR FLUID
Estradiol (estrogen) receptor
Plasma membrane
Hormone-receptor complex
Figure 45.8 Steroid hormone receptors directly regulate gene expression.

27. Estradiol (estrogen) receptor
Figure
Hormone (estradiol)
EXTRACELLULAR FLUID
Estradiol (estrogen) receptor
Plasma membrane
Hormone-receptor complex
NUCLEUS
CYTOPLASM
Figure 45.8 Steroid hormone receptors directly regulate gene expression.
DNA
Vitellogenin
mRNA for vitellogenin

28. Multiple Effects of Hormones
The same hormone may have different effects on target cells that have for two reasons:
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29. Multiple Effects of Hormones
The same hormone may have different effects on target cells that have for two reasons:
Different receptors for the hormone
Different signal transduction pathways
© 2011 Pearson Education, Inc.

30. One hormone, different effects
Same receptors but different intracellular proteins (not shown)
Different receptors
Different cellular responses
Different cellular responses
Epinephrine
Epinephrine
Epinephrine
 receptor
 receptor
 receptor
Glycogen deposits
Figure 45.9 One hormone, different effects.
Vessel dilates.
Vessel constricts.
Glycogen breaks down and glucose is released from cell.
(a) Liver cell
(b)
Skeletal muscle blood vessel
Intestinal blood vessel
(c)

32. Multiple Effects of Hormones
The same hormone may have different effects on target cells that have for two reasons:
Different receptors for the hormone
Different signal transduction pathways
Also……
Perception of physical
response
e.g. “Love on a bridge study”
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33. What functions hormones control…

34. Figure 45.1What signals caused this butterfly to grow within the body of a caterpillar?

35. Regulation of insect development and metamorphosis
Brain
Neurosecretory cells
Corpora cardiaca
Corpora allata
PTTH
Prothoracic gland
Juvenile hormone (JH)
Ecdysteroid
Figure Regulation of insect development and metamorphosis.
EARLY LARVA

36. Regulation of insect development requires multiple hormones
Brain
Neurosecretory cells
Corpora cardiaca
Corpora allata
PTTH
Prothoracic gland
Juvenile hormone (JH)
Ecdysteroid
Figure Regulation of insect development and metamorphosis.
EARLY LARVA
LATER LARVA

37. Juvenile hormone (JH) Low JH
Figure
Brain
Neurosecretory cells
Corpora cardiaca
Corpora allata
PTTH
Prothoracic gland
Juvenile hormone (JH)
Low JH
Ecdysteroid
Figure Regulation of insect development and metamorphosis.
EARLY LARVA
LATER LARVA
PUPA
ADULT

39. Homeostasis: Blood glucose level (70–110 mg/100 mL)
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).
Figure Maintenance of glucose homeostasis by insulin and glucagon.
Homeostasis: Blood glucose level (70–110 mg/100 mL)

40. Body cells take up more glucose. Insulin
Figure 45.13a-2
Body cells take up more glucose.
Insulin
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).
Blood glucose level declines.
Figure Maintenance of glucose homeostasis by insulin and glucagon.
Homeostasis: Blood glucose level (70–110 mg/100 mL)

41. 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.
Figure Maintenance of glucose homeostasis by insulin and glucagon.
Glucagon

42. Homeostasis: Blood glucose level (70–110 mg/100 mL)
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.
Alpha cells of pancreas release glucagon into the blood.
Figure Maintenance of glucose homeostasis by insulin and glucagon.
Liver breaks down glycogen and releases glucose into the blood.
Glucagon

43. 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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44. 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. 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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46. 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
Figure Endocrine glands in the human brain.
Posterior pituitary
Anterior pituitary

47. tropic hormones = target endocrine glands hypothalamus
thyroid-stimulating
hormone
(TSH)
posterior
pituitary
antidiuretic
hormone
(ADH)
Thyroid gland
anterior
pituitary
adrenocorticotropic
hormone (ACTH)
Kidney
tubules
oxytocin
Muscles
of uterus
gonadotropic
hormones:
follicle-
stimulating
hormone (FSH)
& luteinizing
hormone (LH)
growth hormone (GH)
melanocyte-stimulating hormone
(MSH)
prolactin (PRL)
Adrenal
cortex
tropins (tropic hormones) stimulate growth in target organs/cells (tropic means nourishment) When the target organ is another gland, tropic hormones cause them to produce & release their own hormones.
Melanocyte
in amphibian
Mammary
glands
in mammals
Bone
and muscle
Ovaries
Testes

48. Table 45.1a
Table 45.1 Major Human Endocrine Glands and Some of Their Hormones

49. Table 45.1b
Table 45.1 Major Human Endocrine Glands and Some of Their Hormones

50. 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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51. A hormone cascade pathway
Example
Stimulus
Cold
A hormone cascade pathway
Sensory neuron 
Hypothalamus
Hypothalamus secretes thyrotropin-releasing hormone (TRH ).
Neurosecretory cell
Releasing hormone
Blood vessel 
Anterior pituitary secretes thyroid-stimulating hormone (TSH, also known as thyrotropin ).
Anterior pituitary
Tropic hormone
Negative feedback
Thyroid gland secretes thyroid hormone (T3 and T4 ).
Figure A hormone cascade pathway.
Endocrine cell
Hormone
Target cells
Body tissues
Increased cellular metabolism
Response

52. 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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53. Hormones as homologous structures
What does this tell you about these hormones?
How could these hormones have different effects?
prolactin
growth hormone
same gene family
gene duplication?
amphibians
metamorphosis & maturation
mammals
milk production
birds
fat metabolism
fish
salt & water balance
growth & development
The most remarkable characteristic of prolactin (PRL) is the great diversity of effects it produces in different vertebrate species. For example, prolactin stimulates mammary gland growth and milk synthesis in mammals; regulates fat metabolism and reproduction in birds; delays metamorphosis in amphibians, where it may also function as a larval growth hormone; and regulates salt and water balance in freshwater fishes. This list suggests that prolactin is an ancient hormone whose functions have diversified during the evolution of the various vertebrate groups.
Growth hormone (GH) is so similar structurally to prolactin that scientists hypothesize that the genes directing their production evolved from the same ancestral gene. Gene duplication!

54. 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
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55. The roles of parathyroid hormone (PTH) in regulating blood calcium levels in mammals.
Parathyroid gland (behind thyroid)
Figure The roles of parathyroid hormone (PTH) in regulating blood calcium levels in mammals.
STIMULUS: Falling blood Ca2 level
Homeostasis: Blood Ca2 level (about 10 mg/100 mL)

56. Increases Ca2 uptake in intestines Active vitamin D
Figure
Increases Ca2 uptake in intestines
Active vitamin D
Stimulates Ca2 uptake in kidneys
PTH
Parathyroid gland (behind thyroid)
Stimulates Ca2 release from bones
Figure The roles of parathyroid hormone (PTH) in regulating blood calcium levels in mammals.
STIMULUS: Falling blood Ca2 level
Blood Ca2 level rises.
Homeostasis: Blood Ca2 level (about 10 mg/100 mL)

58. Epinephrine and norepinephrine
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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59. Effects of stress on a body
Nerve
signals
Spinal cord
(cross section)
Hypothalamus
Releasing
hormone
Nerve
cell
Anterior pituitary
Blood vessel
adrenal medulla
secretes epinephrine
& norepinephrine
Nerve cell
Adrenal cortex
secretes
mineralocorticoids
& glucocorticoids
ACTH
Adrenal
gland
Kidney
MEDULLA
CORTEX
(A) SHORT-TERM STRESS RESPONSE
(B) LONG-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
Effects of
mineralocorticoids:
1. Retention of sodium ions & water by kidneys
2. Increased blood volume & blood pressure
Effects of
glucocorticoids:
1. Proteins & fats broken down & converted to glucose, leading to increased blood glucose
2. Immune system suppressed

60. Short-term stress response and the adrenal medulla (b)
Figure 45.21
(a)
Short-term stress response and the adrenal medulla
(b)
Long-term stress response and the adrenal cortex
Stress
Nerve signals
Hypothalamus
Spinal cord (cross section)
Releasing hormone
Nerve cell
Anterior pituitary
Blood vessel
Nerve cell
ACTH
Adrenal medulla secretes epinephrine and norepinephrine.
Adrenal cortex secretes mineralo- corticoids and glucocorticoids.
Adrenal gland
Kidney
Figure Stress and the adrenal gland.
Effects of epinephrine and norepinephrine:
Effects of mineralocorticoids:
Effects of glucocorticoids:
Glycogen broken down to glucose;
increased blood glucose
• Retention of sodium ions and water by kidneys
• Proteins and fats broken down and converted to glucose, leading to increased blood glucose
Increased blood pressure
Increased breathing rate
Increased metabolic rate
• Increased blood volume and blood pressure
Change in blood flow patterns, leading to increased alertness and decreased digestive, excretory, and reproductive system activity
• Partial suppression of immune system

61. Mineralocorticoids, such as aldosterone, affect salt and water balance
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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62. 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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63. 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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64. What role do hormones play in making a mammal male or female?
RESULTS
Appearance of Genitalia
Embryonic gonad removed
Chromosome Set
No surgery
XY (male)
Male
Female
Figure Inquiry: What role do hormones play in making a mammal male or female?
XX (female)
Female
Female

65. Melatonin and Biorhythms
The pineal gland, located in the brain, secretes melatonin
Light/dark cycles control release of melatonin
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66. 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.