1. Hormones and the Endocrine System
Everything is Regulated
Learning Targets
Insulin and glucagon are secreted by β and α cells of the pancreas respectively to control blood glucose concentration.
Thyroxin is secreted by the thyroid gland to regulate the metabolic rate and help control body temperature.
Leptin is secreted by cells in adipose tissue and acts on the hypothalamus of the brain to inhibit appetite.
Melatonin is secreted by the pineal gland to control circadian rhythms.
Know the causes and treatments of Type I and Type II Diabetes.

2. Hormones and the Endocrine System
Everything is Regulated
The endocrine system is the only other signaling system in your body besides the nervous system. It comprises all of the glands that secrete hormones into your circulatory system.
Hormones are signaling molecules released by glands in the body that travel to target organs and affect physiology and behavior.
Digestion, excretion, metabolism, sensory perception, respiration, lactation, movement, growth and development, reproduction, sleep, stress and mood and are regulated by hormones.

3. Endocrine and Hormone Example: Controlling Blood Glucose with Insulin
High blood glucose: blurred vision, fatigue, poor wound healing, cardiac arrhythmia, coma and seizures.
Low blood glucose: anxiety, headaches, numbness, fatigue, impaired vision, slurred speech, comas and seizures.
Insulin and glucagon are secreted by α and β cells of the pancreas to control blood glucose concentration.

4. Controlling blood glucose levels

5. Diabetes: continually elevated blood glucose
Risks of living with Diabetes: tissue damage and can result in serious long-term complications such as heart disease, stroke, kidney failure, blindness, and damage to the extremities.
Diabetes doubles your risk of early death.
About 8.5% of the world’s adults have diabetes, causing 1.5 million deaths in 2012 and making it the 8th leading cause of death worldwide.

6. A Day in the Life of a Diabetic
Type I Diabetes
A Day in the Life of a Diabetic
Early-onset diabetes
Caused by an inability to produce insulin, often because the body’s own immune system destroys the beta cells in the pancreas.
Treated with timed injections of insulin and careful monitoring of blood sugar levels.

7. Where does synthetic insulin come from? Oh no! A GMO!
Since 1982 a strain of E. coli bacteria has been modified into a transgenic organism (GMO) with the human insulin gene. Today drug companies use E. coli to produce over 17,000 kg of insulin per year, which keeps tens of millions of diabetics around the world alive.
Link (with citations) to Dr. Strode’s Royal Banner commentary on transgenic technology.

8. https://microbialcellfactories. biomedcentral. com/articles/10
Figure 1. Percentage of biopharmaceuticals produced in different expression systems.

9. Type II Diabetes Late on-set diabetes
Caused by an inability of the body’s cells to respond properly to insulin, known as insulin resistance. Insulin receptors no longer function properly
Caused by genetics and lifestyle factors such as obesity, lack of physical activity, poor diet, and stress.
90% of diabetes cases worldwide are type II.
Treated with healthy diet and exercise, monitoring of blood sugar, oral medication and insulin.

10. Leptin
Leptin is secreted by cells in adipose (fat storage) tissue and acts on the hypothalamus of the brain to inhibit appetite.
More adipose tissue = higher blood leptin concentrations = long-term appetite inhibition.
Too much leptin in the blood can cause leptin receptors to become resistant to it, much like type II diabetes.
The mouse on the left is unable to create leptin. The mouse on the right is able to produce leptin.
Leptin Activity Animation and Description

11. Melatonin is secreted by the pineal gland to control circadian rhythms.
Melatonin controls the sleep-wake cycle. It is released in the evening and removed by the liver in the morning.
High concentrations of melatonin make people feel tired and drowsy.

12. Thyroxin is secreted by the thyroid gland and regulates the metabolic rate and helps control body temperature.
Affects metabolic rate of all cells in the body, but especially affects the liver, muscle, and brain.
Higher metabolic rate results in more protein synthesis, growth, and generation of body heat.
Cooling triggers the production of thyroxin, so the body heats up.
Thyroxin deficiency can lead to a lack of energy, forgetfulness, depression, weight gain, feeling cold, constipation and impaired brain development.

13. Biological sex determination
Hormones and Human Reproductive Systems
Biological sex determination
The Sex-determining Region Y (SRY), a gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone.

14. Biological sex determination
Testosterone causes pre-natal development of male genitalia and both sperm production and development of male secondary sexual characteristics during puberty.

15. Biological sex determination
Estrogen and progesterone cause pre-natal development of female reproductive organs and female secondary sexual characteristics during puberty.
Estrogen
Progesterone
Testosterone

20. Progesterone (an estrogen) in pill tricks the body into thinking it’s pregnant and suppresses luteinizing hormone.