1. Pancreatic Hormones

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Pancreas
The pancreas is both an endocrine and exocrine gland. It is located in the curve of the duodenum.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.

3. Exocrine is NOT endocrine, remember?
Pancreas - Exocrine
Secretes enzymes involved in digestion
Exocrine is NOT endocrine, remember?
Moving on…

4. Pancreatic Importance!!
Endocrine roles of the pancreas are to:
Maintain a constant blood glucose level
Facilitate cellular storage of foodstuffs following a meal
Provide for mobilization of metabolic substrates during periods of fasting
Over and under production of insulin and glucagon can affect storage and use of CHO, fats, and proteins within the liver, adipose tissue, and muscle.

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Pancreatic Islets

6. Endocrine Pancreas
There are ~ 1 to 2 million islets in the normal human pancreas which is only 1-2% of the pancreatic tissue
Two cell types can be visualized histologically:
a cells → glucagon (15-20%)
b cells → insulin (60-85%)
Other cells exist in smaller numbers
D cells → SST (3-10%)
F cells → pancreatic polypeptide (3-5%)
Epsilon cells → ghrelin (<1%)
Cortisol, epi, norepi- anti insulin

7. Insulin
Insulin is one of a number of hormones that is needed for normal growth and development
Insulin directly lowers blood glucose levels
most others tend to elevate blood glucose
Absolute insulin deficiency results in unrestrained glucose production, lipolysis, ketogenesis, proteolysis, and death
Insulin excess can result in hypoglycemia, brain failure and death
T3 and T4 are also needed for normal growth and development

8. Glucagon
During fasting, prevention of hypoglycemia is not solely due to decreased insulin secretion but also to an increase in glucagon.
Adrenal catecholamines become important when glucagon is deficient.

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Pancreatic Islets
Secretion of insulin and glucagon are controlled by negative feedback.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.

10. Diabetes
In patients with T1DM, there is a decrease in the number of insulin-containing beta cells.
This may result from development of cell surface AB.
It may be caused by a virus.
Type II diabetics have above normal levels of insulin but their tissues do not respond to the hormone
A.k.a. insulin resistance

11. Gonads

12. Ovaries and Testes Gonads produce gametes Ovaries produce:
Men  Testes produce sperm
Women  Ovaries produce oocytes
Ovaries produce:
2 estrogens (estradiol and estrone)
Progesterone
Relaxin  Pregnancy/Partruiton
Inhibin  FSH
Testes produce testosterone.
Also Inhibin

13. Odds & Ends

14. Pineal Gland Pineal gland Attached to the roof of the third ventricle
Secretes melatonin - helps to regulate the body’s biological clock.

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Thymus
Located behind the sternum, between the lungs.
Produces:
Thymosin
Thymic humoral factor (THF)
Thymic factor (TF)
Thymopoietin
All of which promote maturation of the immune system’s T cells.
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16. Pineal Gland and Thymus
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Pineal Gland and Thymus

17. Other Hormone Producers
Several tissues and organs which are not part of the endocrine system are able to produce hormones.
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18. Other Endocrine Tissues and Organs
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Other Endocrine Tissues and Organs

19. Eicosanoids and Growth Factors
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Eicosanoids and Growth Factors
Eicosanoids
Locally-acting hormones
Derived from arachadonic acid (F.A.)
Growth Factors
Stimulate cell growth and division.
Involved in tissue development, growth and repair.

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Growth Factors

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The Stress Response
Eustress - helpful, everyday stress that prepares us to meet challenges.
Distress - harmful stress that may be damaging.
Fight-or-flight response
1st stage of the stress response
Stimulates the body’s resources to prepare for immediate activity.
Resistance reaction
2nd stage in the stress response
Lasts longer than the fight-or-flight response.

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The Stress Response

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Focus on Homeostasis

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Endocrine Disorders
There are many endocrine disorders. Some are more common than others.
Pituitary gigantism and acromegaly are caused by excess secretion of growth hormone.
Goiter is caused by a reduction in the production of thyroid hormone.
Graves disease (with associated exophthalmos) develops due to excess thyroid hormone.
Cushing’s syndrome is caused by excess secretion of glucocorticoids.

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Endocrine Disorders