1. Copyright 2009, John Wiley & Sons, Inc.
Pancreas
Copyright 2009, John Wiley & Sons, Inc.

2. Copyright 2009, John Wiley & Sons, Inc.
Pancreatic Islets
Both exocrine and endocrine gland
Roughly 99% of cells produce digestive enzymes
Pancreatic islets or islets of Langerhans
Alpha or A cells secrete glucagon – raises blood sugar
Beta or B cells secrete insulin – lowers blood sugar
Delta or D cells secrete somatostatin – inhibits both insulin and glucagon
F cells secrete pancreatic polypeptide – inhibits somatostatin, gallbladder contraction, and secretion of pancreatic digestive enzymes
Copyright 2009, John Wiley & Sons, Inc.

3. Cell Types in the Pancreatic Islets
Alpha cells (20%) produce glucagon
Beta cells (70%) produce insulin
Delta cells (5%) produce somatostatin
F cells produce pancreatic polypeptide

4. Insulin acts on various
body cells to:
• accelerate facilitated
diffusion of glucose
into cells
• speed conversion of
glucose into glycogen
(glycogenesis)
• increase uptake of
amino acids and increase
protein synthesis
• speed synthesis of fatty
acids (lipogenesis)
• slow glycogenolysis
• slow gluconeogenesis
Glucagon acts on
hepatocytes
(liver cells) to:
• convert glycogen
into glucose
(glycogenolysis)
• form glucose from
lactic acid and
certain amino acids
(gluconeogenesis)
Glucose released
by hepatocytes
raises blood glucose
level to normal
If blood glucose
continues to rise,
hyperglycemia inhibits
release of glucagon
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete
High blood glucose
(hyperglycemia)
stimulates beta cells
to secrete
INSULIN
GLUCAGON 1 5 2 3 4 6
Insulin acts on various
body cells to:
• accelerate facilitated
diffusion of glucose
into cells
• speed conversion of
glucose into glycogen
(glycogenesis)
• increase uptake of
amino acids and increase
protein synthesis
• speed synthesis of fatty
acids (lipogenesis)
• slow glycogenolysis
• slow gluconeogenesis
Blood glucose level falls
Glucagon acts on
hepatocytes
(liver cells) to:
• convert glycogen
into glucose
(glycogenolysis)
• form glucose from
lactic acid and
certain amino acids
(gluconeogenesis)
Glucose released
by hepatocytes
raises blood glucose
level to normal
If blood glucose
continues to rise,
hyperglycemia inhibits
release of glucagon
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete
High blood glucose
(hyperglycemia)
stimulates beta cells
to secrete
INSULIN
GLUCAGON 1 5 2 3 4 6 7
Insulin acts on various
body cells to:
• accelerate facilitated
diffusion of glucose
into cells
• speed conversion of
glucose into glycogen
(glycogenesis)
• increase uptake of
amino acids and increase
protein synthesis
• speed synthesis of fatty
acids (lipogenesis)
• slow glycogenolysis
• slow gluconeogenesis
If blood glucose continues
to fall, hypoglycemia
inhibits release of
insulin
Blood glucose level falls
Glucagon acts on
hepatocytes
(liver cells) to:
• convert glycogen
into glucose
(glycogenolysis)
• form glucose from
lactic acid and
certain amino acids
(gluconeogenesis)
Glucose released
by hepatocytes
raises blood glucose
level to normal
If blood glucose
continues to rise,
hyperglycemia inhibits
release of glucagon
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete
High blood glucose
(hyperglycemia)
stimulates beta cells
to secrete
INSULIN
GLUCAGON 1 5 2 3 4 6 7 8
Glucagon acts on
hepatocytes
(liver cells) to:
• convert glycogen
into glucose
(glycogenolysis)
• form glucose from
lactic acid and
certain amino acids
(gluconeogenesis)
Glucose released
by hepatocytes
raises blood glucose
level to normal
If blood glucose
continues to rise,
hyperglycemia inhibits
release of glucagon
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete
High blood glucose
(hyperglycemia)
stimulates beta cells
to secrete
GLUCAGON 1 5 2 3 4
INSULIN
Glucagon acts on
hepatocytes
(liver cells) to:
• convert glycogen
into glucose
(glycogenolysis)
• form glucose from
lactic acid and
certain amino acids
(gluconeogenesis)
Glucose released
by hepatocytes
raises blood glucose
level to normal
If blood glucose
continues to rise,
hyperglycemia inhibits
release of glucagon
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete
GLUCAGON 1 2 3 4
Glucagon acts on
hepatocytes
(liver cells) to:
• convert glycogen
into glucose
(glycogenolysis)
• form glucose from
lactic acid and
certain amino acids
(gluconeogenesis)
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete
GLUCAGON 1 2
Glucagon acts on
hepatocytes
(liver cells) to:
• convert glycogen
into glucose
(glycogenolysis)
• form glucose from
lactic acid and
certain amino acids
(gluconeogenesis)
Glucose released
by hepatocytes
raises blood glucose
level to normal
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete
GLUCAGON 1 2 3
Low blood glucose
(hypoglycemia)
stimulates alpha
cells to secrete 1
GLUCAGON

5. Copyright 2009, John Wiley & Sons, Inc.
Pineal Gland
Copyright 2009, John Wiley & Sons, Inc.

6. Copyright 2009, John Wiley & Sons, Inc.
Pineal Gland
Attached to roof of 3rd ventricle of brain at midline
Masses of neuroglia and pinealocytes
Melatonin – amine hormone derived from serotonin
Appears to contribute to setting biological clock
More melatonin liberated during darkness than light
Copyright 2009, John Wiley & Sons, Inc.

8. SCN and sleep Wild type animal with period of ~24h Tau mutant
Basics of Sleep Guide: Chronobiology
SCN and sleep
4/24/2017
4/24/2017
Wild type animal
with period of ~24h
Tau mutant
with period of ~20h A
SCN lesioning B
Transplanting SCN
of donor with ~20-h period C
SCN lesioning
abolishes circadian rhythm
Wild type animal acquires
period of donor (~20h)
Modified from Ralph and Lehman, Trends Neuro 1991
Scheer-Shea Set #8 8 8

9. Melatonin: Produced by pineal gland, released at night-inhibited during the day (circadian regulation); initiates and maintain sleep; treat symptoms of jet lag and insomnia

10. Hypothalamus and Pituitary Gland

11. Copyright 2009, John Wiley & Sons, Inc.
Anterior pituitary
Release of hormones stimulated by releasing and inhibiting hormones from the hypothalamus
Also regulated by negative feedback
Hypothalamic hormones made by neurosecretory cells transported by hypophyseal portal system
Anterior pituitary hormones that act on other endocrine systems called tropic hormones
Copyright 2009, John Wiley & Sons, Inc.

12. Hormones of the Anterior Pituitary
Human growth hormone (hGH) or somatotropin
Stimulates secretion of insulin-like growth factors (IGFs) that promote growth, protein synthesis
Thyroid-stimulating hormone (TSH) or thyrotropin
Stimulates synthesis and secretion of thyroid hormones by thyroid
Follicle-stimulating hormone (FSH)
Ovaries initiates development of oocytes, testes stimulates testosterone production
Luteinizing hormone (LH)
Ovaries stimulates ovulation, testes stimulates testosterone production
Copyright 2009, John Wiley & Sons, Inc.

13. Hormones of the Anterior Pituitary
Prolactin (PRL)
Promotes milk secretion by mammary glands
Adrenocorticotropic hormone (ACTH) or corticotropin
Stimulates glucocorticoid secretion by adrenal cortex
Melanocyte-stimulating Hormone (MSH)
Copyright 2009, John Wiley & Sons, Inc.

14. Function of Anterior Pituitary Hormones
Copyright 2009, John Wiley & Sons, Inc.

15. 1) Human Growth Hormone
Increases synthesis of insulin-like growth factors “(IGFs) or somatomedins” at target cells
target cells are liver, skeletal muscle, cartilage and bone. IGF will work locally or enter bloodstream and they will lead to:
increases cell growth & cell division
Increases cell uptake of amino acids & synthesis of proteins
stimulate lipolysis in adipose so fatty acids used for ATP
retard use of glucose for ATP production so blood glucose levels remain high enough to supply brain
Increases plasma free fatty acids (FFA) - source of energy for muscle tissue
Increases hepatic glucose output
Decreases insulin sensitivity in muscle
Is protein anabolic hormone

16. Regulation of hGH
Low blood sugar stimulates release of GNRH from hypothalamus
anterior pituitary releases more hGH, more glycogen broken down into glucose by liver cells
High blood sugar stimulates release of GHIH from hypothalamus
less hGH from anterior pituitary, glycogen does not breakdown into glucose

17. Diabetogenic Effect of Human Growth Hormone
Excess of growth hormone
raises blood glucose concentration
pancreas releases insulin continually
beta-cell burnout
Diabetogenic effect
causes diabetes mellitis

18. 2) Thyroid Stimulating Hormone (TSH)
Hypothalamus regulates the production of Thyroid Stimulating Hormone (TSH)
TSH stimulates the synthesis & secretion of T3 and T4 at thyroid gland
Metabolic rate stimulated

19. 3) Follicle Stimulating Hormone (FSH)
FSH functions
initiates the formation of follicles within the ovary
stimulates follicle cells to secrete estrogen
stimulates sperm production in testes

20. 4) Luteinizing Hormone (LH)
In females, LH stimulates
secretion of estrogen(with FSH)
ovulation of secondary
oocyte from ovary
formation of corpus luteum
secretion of progesterone
In males, stimulates interstitial cells to secrete testosterone

21. 5) Prolactin (PRL)
Under right conditions, prolactin causes milk production
Suckling reduces cause prolactin levels rise along with milk production
Nursing ceases & milk production slows

22. 6) Adrenocorticotrophic Hormone
ACTH stimulates cells of the adrenal cortex that produce glucocorticoids

23. 7) Melanocyte-Stimulating Hormone
Releasing hormone from hypothalamus increases its release From the anterior pituitary
Function not certain in humans (increase skin pigmentation in frogs )

24. Regulation of Ant. Pitutary Hormone Secretion
negative feedback
Hypothalamus
Copyright 2009, John Wiley & Sons, Inc.

25. Hypothalamus
Hypothalamus is a section of brain above where pituitary gland is suspended from by infundibulum or stalk

27. Functions of hypothalamus
Endocrine function
Caloric balance
Osmolarity balance
Thermal regulation
Autonomic balance
Sleep
Affective behavior
Memory
Somatic movements

29. Copyright 2009, John Wiley & Sons, Inc.
Hypothalamus
Hypothalamus is a section of brain above where pituitary gland is suspended from by infundibulum or stalk
Hypothalamus is a major link between nervous and endocrine system
It receives input from cortex, thalamus, limbic system & internal organs
Is influenced by emotions and the metabolic state of the individual
Copyright 2009, John Wiley & Sons, Inc.

30. Hypothalamus Releasing Hormones: Secretion
Synthesizes hormones in cell bodies of neurons
Hormones are transported down the axon and stored in the nerve endings

31. Hypothalamus Releasing Hormones: Secretion
Synthesizes hormones in cell bodies of neurons
Hormones are transported down the axon and stored in the nerve endings
Delivered to the anterior pituitary via the hypothalamic-hypophyseal portal system
Usually initiates a three-hormone sequence
Hypothalamus controls pituitary gland with 7 different releasing & inhibiting hormones

32. Hypothalamus and anterior pituitary

33. Flow of Blood to Anterior Pituitary
Controlling hormones enter blood
Travel through portal veins
Enter anterior pituitary at capillaries

34. Hypothalamic control of anterior pituitary secretions

35. Hypothalamus Releasing Hormones: Secretion
Synthesizes hormones in cell bodies of neurons
Hormones are transported down the axon and stored in the nerve endings
Delivered to the anterior pituitary via the hypothalamic-hypophyseal portal system
Usually initiates a three-hormone sequence
Hypothalamus controls pituitary gland with 7 different releasing & inhibiting hormones

36. Endocrine Control: Three Levels of Integration
Figure 7-13: Hormones of the hypothalamic-anterior pituitary pathway

37. Hypothalamus Releasing Hormones: Secretion
Synthesizes hormones in cell bodies of neurons
Hormones are transported down the axon and stored in the nerve endings
Delivered to the anterior pituitary via the hypothalamic-hypophyseal portal system
Usually initiates a three-hormone sequence
Hypothalamus controls pituitary gland with 7 different releasing & inhibiting hormones

38. Hypothalamic control of anterior pituitary
Effect on Ant Pituitary
Hormones
(+) TSH & Prolactin
Thyrotropin-releasing hormone (TRH) 1.
(+) ACTH
Corticotropin-releasing hormone (CRH) 2.
(+) GH
Growth hormone releasing hormone (GHRH) 3.
(+) Prolactin
Prolactin releasing hormone (PRH) 4.
(+) Gonadotropic hormones
(LH, & FSH)
Gonadotropin-releasing hormone (GnRH) 5.
(-) Prolactin
Prolactin inhibitory hormone (PIH)
“Dopamine” 6.
(-) GH
(-) TSH
Growth hormone inhibitory hormone (GHIH) “Somatostatin (SS)” 7.

39. Hypothalamic hormones
Hypothalamus
GnRH
GHRH
GHIH/SS
TRH
PRIH
PRH
CRH + + - - + + - + +
FSH & LH GH
TSH
Prolactin
ACTH
Anterior Pituitary
Copyright 2009, John Wiley & Sons, Inc.

40. Regulation of Ant. Pitutary Hormone Secretion
negative feedback
Hypothalamus
Copyright 2009, John Wiley & Sons, Inc.

41. Negative Feedback Regulation
Copyright 2009, John Wiley & Sons, Inc.

42. GHIH inhibits
secretion of
hGH by
somatotrophs
Low blood glucose
(hypoglycemia)
stimulates release of
High blood glucose
(hyperglycemia)
hGH
GHRH stimulates
secretion
of hGH by
GHIH
GHRH
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly
Blood glucose level
rises to normal
(about 90 mg/100 mL)
If blood glucose
continues to increase,
hyperglycemia inhibits
release of GHRH 1 6 7 3 4 5 2
GHIH inhibits
secretion of
hGH by
somatotrophs
Low blood glucose
(hypoglycemia)
stimulates release of
High blood glucose
(hyperglycemia)
Anterior
pituitary
hGH
GHRH stimulates
secretion
of hGH by
GHIH
GHRH
A low level of hGH and
IGFs decreases the rate
of glycogen breakdown
in the liver and glucose
enters the blood more
slowly
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly
Blood glucose level
rises to normal
(about 90 mg/100 mL)
If blood glucose
continues to increase,
hyperglycemia inhibits
release of GHRH 1 6 7 8 3 4 5 2
GHIH inhibits
secretion of
hGH by
somatotrophs
Low blood glucose
(hypoglycemia)
stimulates release of
High blood glucose
(hyperglycemia)
Anterior
pituitary
hGH
GHRH stimulates
secretion
of hGH by
GHIH
GHRH
A low level of hGH and
IGFs decreases the rate
of glycogen breakdown
in the liver and glucose
enters the blood more
slowly
Blood glucose level
falls to normal
(about 90 mg/100 mL)
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly
rises to normal
If blood glucose
continues to increase,
hyperglycemia inhibits
release of GHRH 1 6 7 8 9 3 4 5 2
GHIH inhibits
secretion of
hGH by
somatotrophs
Low blood glucose
(hypoglycemia)
stimulates release of
High blood glucose
(hyperglycemia)
Anterior
pituitary
hGH
GHRH stimulates
secretion
of hGH by
GHIH
GHRH
A low level of hGH and
IGFs decreases the rate
of glycogen breakdown
in the liver and glucose
enters the blood more
slowly
Blood glucose level
falls to normal
(about 90 mg/100 mL)
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly
rises to normal
If blood glucose
continues to increase,
hyperglycemia inhibits
release of GHRH
continues to decrease,
hypoglycemia inhibits
release of GHIH 1 6 7 8 9 10 3 4 5 2
Low blood glucose
(hypoglycemia)
stimulates release of
High blood glucose
(hyperglycemia)
hGH
GHRH stimulates
secretion
of hGH by
somatotrophs
GHIH
GHRH
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly
Blood glucose level
rises to normal
(about 90 mg/100 mL)
If blood glucose
continues to increase,
hyperglycemia inhibits
release of GHRH 1 6 3 4 5 2
Anterior
pituitary
Low blood glucose
(hypoglycemia)
stimulates release of
hGH
GHRH stimulates
secretion
of hGH by
somatotrophs
GHRH
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly
Blood glucose level
rises to normal
(about 90 mg/100 mL)
If blood glucose
continues to increase,
hyperglycemia inhibits
release of GHRH 1 3 4 5 2
Anterior
pituitary
Low blood glucose
(hypoglycemia)
stimulates release of
hGH
GHRH stimulates
secretion
of hGH by
somatotrophs
GHRH 1 2
Low blood glucose
(hypoglycemia)
stimulates release of
hGH
GHRH stimulates
secretion
of hGH by
somatotrophs
GHRH
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly 1 3 2
Low blood glucose
(hypoglycemia)
stimulates release of
hGH
GHRH stimulates
secretion
of hGH by
somatotrophs
GHRH
hGH and IGFs speed
up breakdown of liver
glycogen into glucose,
which enters the blood
more rapidly
Blood glucose level
rises to normal
(about 90 mg/100 mL) 1 3 4 2
Low blood glucose
(hypoglycemia)
stimulates release of
GHRH 1