2. How have you changed over the past year?
What has caused those changes?
How do you think you will change in the next few years?

3. The Endocrine System regulates, coordinates and controls:
Growth and development.
Male and female development.
How your body uses energy.
Levels of salts and sugars in your blood.
The amount (volume) of fluid in your body.
Appetite.
Many other body functions.

4. The Endocrine Glands are the organs of the Endocrine System.
They produce and secrete (release) Hormones.
They are located all over your body.

5. Gland What it Regulates Pituitary
“Master Gland” that regulates all other Endocrine Glands, also releases growth hormone
Thyroid
Metabolism, body heat, bone growth
Parathyroids
Use of Calcium and Phosphorous
Hypothalamus
Links nervous system to endocrine system
Adrenal
Response in emergency or stressful situations, metabolism, blood pressure, salt balance
Pancreas
Blood sugar
Ovaries
Production of eggs; female characteristics
Testes
Production of sperm; male characteristics
Thymus
Parts of the immune system

6. The answer is Hormones!

7. Hormones are chemical messengers that are secreted (released) from glands into the blood and affect cells in another part of the body.
Because they are in the blood, hormones can get transported to the organs (genitals, brain, blood vessels, etc.).

8. Hormones only work on certain cells, called target cells.
The target cells have special receptors that “recognize” the hormones and allow them to influence that cell.
Target Cell for Hormone A
Target Cell for Hormone A
Target Cell for Hormones A and B
Target Cell for Hormone B
Hormone A
Hormone B
These receptors recognize the hormones.
They “fit” like a lock and key.

9. External stimuli Internal stimuli
by way of nerves from the sensory organs in the nervous system
by way of nerves and other hormones from inside the body
Nerves and various hormones act on the brain to affect the what the brain does. Such action can affect both behavior and certain control functions of the brain on the body (including feedback control on the level of hormones). External stimuli through the sense organs can also act on the brain to affect what it does.

10. Brain also reacts by way of nerves from hypothalamus and brainstem
Brain reacts by way of secretions from neurons in hypothalamus (neurohormones)
Brain also reacts by way of nerves from hypothalamus and brainstem
The hypothalamus controls the many gland cells in the pituitary by way of secretions from the hypothalamus that get carried by venous blood into the pituitary. Various hormones from the pituitary control many other organs that make hormones. That is why the pituitary is called the “master gland” of the body. The hypothalamus and some neurons in the brainstem supply peripheral nerves that provide automatic and subconscious control over many vital functions, such as blood-vessel diameter, rate and strength of heart beat. This system also can “turn on” the adrenal gland to make adrenalin, a true hormone that raises blood pressure, increases heart rate and strength of contraction.
“Autonomic Nervous System”

11. What is the difference between nerve and hormone control?
They control in different ways.
Why both kinds of controls?
Nerve action is quick (think reflexes) and can be stopped quickly. Hormone action is slower to develop and can last a lot longer.

12. Remember, external means coming from outside of your body and internal means coming from inside of your body.

13. Stimulus: You hear a loud noise
A large dog runs toward you, growling and barking
You eat a large candy bar
You have not eaten in six hours
You have strep throat
Ask the students to classify these stimuli as external, internal, or combination of both.

14. A chain of events occur that lead from the stimulus to the response.
Picture from:

15. Negative feedback means that when enough hormone is in the body, the body stops producing the hormone until it is needed again.
Increased glucose is detected by receptors
that notify the brain. It sends a message
to the pancreas to produce insulin.
You eat. Glucose (sugar)
in the blood increases.
Have students locate the places where there are stimuli and responses. Note that these stimuli are internal (within the body).
Point out the places where the pancreas produces insulin when blood sugar is high, but then stops producing insulin when the blood sugar drops.
This ties into the activities of building the dog watering device and the cup demonstration activity.
Description:
A good example of negative feedback is the hormone insulin. Insulin is a hormone that is made by the pancreas. Insulin is released by the pancreas when you eat glucose (a kind of sugar). The glucose goes from your stomach to the blood. The amount of glucose in the blood goes up. The pancreas sees this high glucose level. It makes insulin and releases it into the blood. Then the insulin goes through the whole body and tells cells to take glucose out of the blood. Cells use some of this for energy. But some extra is also saved in the cells to use later. When cells take up glucose from the blood this makes the glucose level go down. The pancreas sees this and stops making insulin. When the pancreas stops sending this message (insulin), the cells in the body stop taking extra glucose out of the blood.
So the negative feedback works to keep the blood glucose level normal. If glucose is high, the pancreas makes insulin. The insulin causes the glucose to fall. Then this lower level of glucose tells the pancreas to stop making insulin.
Pancreas stops making insulin.
Insulin tells muscle and liver to take up
glucose from the bloodstream and use it for energy
or store it for later. Brain reduces appetite.
Blood glucose level drops as
it is removed by the cells.

16. Diabetes
In diabetes, either the body does not produce enough insulin or the cells ignore the insulin. Insulin is necessary for the body to be able to use glucose for energy. When you eat food, the body breaks down all of the sugars and starches into glucose, which is the basic fuel for the cells in the body. Insulin takes the sugar from the blood into the cells. When glucose builds up in the blood instead of going into cells, it can lead to diabetes complications.
In the case shown in this picture, the body produces insulin but the target cells become resistant and unresponsive to it. Diabetes can also be caused by the body not producing enough insulin. The glucose does not enter the muscle and liver cells like it should and it builds up in the blood causing complications.

18. A few hormone systems are positive feedback systems:
The pituitary gland sends a signal by way of the hormone oxytocin to the uterus causing contractions. The pressure of the fetus on the cervix sends a signal back to the brain which then stimulates the release of more oxytocin. This causes more contractions. The fetus pushes harder on the cervix. More oxytocin is released. The system continues until birth occurs.
Vocabulary:
Fetus- The unborn baby calf
Uterus-the reproductive organ that holds the developing fetus
Cervix- the lower part of the uterus that is tightly closed until birth, upon which it opens to allow the baby to pass through to be born
Again, have students identify the stimuli and responses.
Description of picture:
An example of positive feedback is the hormone that causes childbirth (when babies are born.) The hormone that causes this is oxytocin. When the baby is ready to be born, it stretches the muscle in the cervix (the bottom of the womb.) Nerves in the cervix send a message to the pituitary. This message makes the pituitary release more oxytocin. The oxytocin then causes the muscles of the womb to contract, or squeeze. This causes more stretching in the cervix. This stretching then tells the pituitary to make even more oxytocin. So levels of oxytocin keep rising until the squeezing or contractions of the womb force the baby out. (The womb is also called the uterus.)

19. When normal functions lose their negative feedback control, many times disease is the result.
An example:
Neurons in the hypothalamus secrete thyroid releasing hormone (TRH), which stimulates cells in the anterior pituitary to secrete thyroid-stimulating hormone (TSH).
TSH binds to receptors to cells in the thyroid gland, stimulating thyroid hormones, which affect all cells in the body.
When blood concentrations of thyroid hormones increase above a certain level, TRH-secreting neurons in the hypothalamus are inhibited and stop secreting TRH.
If this process is disrupted, the Thyroid keeps producing hormones and hyperthyroid disease ensues.
Disruption

20. Where it comes from: Adrenal Gland
Where it acts: heart, blood vessels, eyes
What it does: stimulates heart rate, increases blood pressure, dilates pupils
Causes "Adrenaline Rush”
A 'fight and flight' hormone.
It is released in high stress conditions or in excitement or fear.
Loud noise, high temperature etc. may also trigger its release since these are also high stress situations.

21. Where it comes from: ovary (where an egg was released)
Where it acts: uterus
What it does: controls menstruation in women and plays a role in pregnancy.
One of the components of birth control pills

22. Where it comes from: thyroid gland
Where it acts: most cells of the body
What it does: controls the rate of metabolic processes (how energy is used) in the body and influences physical development
People may not produce enough of this hormone and get a condition known as hypothyroidism. They can take thyroxine to treat this condition.

23. Where it comes from: testicles
Where it acts: body-hair cells, muscle, reproductive structures
What it does: stimulates development of male sexual characteristics
Testosterone is a steroid and has been administered to athletes in order to improve performance. This is considered to be a form of doping in most sports and is a very dangerous practice.
Females also produce small amounts of testosterone in their ovaries that affect muscle development and other body functions.

24. Where it comes from: ovary
Where it acts: breast tissue, reproductive structures in female
What it does: stimulates development of female sexual characteristics
Estrogen levels may be related somehow to migraine headaches in women.

25. Where it comes from: outer part of adrenal gland
Where it acts: multiple tissues
What it does: mental stimulation, breaks down fat and protein to glucose, anti-inflammation
It is usually referred to as the "stress hormone" as it is involved in response to stress and anxiety.

26. Where it comes from: Insulin is produced in the pancreas
Where it acts: liver, muscle, and fat tissue
What it does: Insulin causes cells to take up glucose (sugar) from the blood, storing it in the liver and muscle, and stopping use of fat as an energy source.
Problems with insulin production or use in the body can lead to diabetes.
The adrenal gland also secretes steroids that affect mineral balance.

27. What are the functions of the Endocrine System?
Name 5 Endocrine Glands and what they do.
What are hormones?
How do hormones work?
Name some hormones and what they do.
At what times in your life do you think your Endocrine System is most active?