Biology Hormones

The Endocrine SystemThe endocrine system is a collection of glands in your body that produce hormones. The hormones regulate metabolism,

growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things.

Main Glands: pituitary gland thyroid gland

parathyroid glands adrenal glands

pancreasovaries (in females)testicles (in males)

HormonesHormones are powerful chemicals that help keep our bodies working normally. They stimulate, regulate, and control the function of various tissues and organs.

Made by specialized groups of cells within structures called glands, hormones are

involved in almost every biological process including sexual reproduction, growth,

metabolism, and immune function.

Unlike the fast-acting chemicals of your nervous system (neurotransmitters), the hormones of your endocrine

system work slowly in your body.

How much of our behavior is hormonal?

Take for example PMS (premenstrual syndrome): emotional and physical symptoms that women experience sometime during the

10 days before their menstrual cycle (period) begins. Women might experience mood swings, depression, crying spells, anger, irritability, anxiety, social withdrawal, or lack of concentration.

…And this is due to chemical changes within the body!

PMS can also cause a lack of serotonin in the brain, triggering depression.

Diet, weight changesHigh stress

Puberty in teenage yearsAging

Menstrual cycle (women)Certain diseases

Changes in moodTiredness/fatigue

Unexplained weight loss or gainAnxiety, irritability, depression

AggressionAcne

Thyroid

Pituitary

Ovaries

Testes

Adrenal

Hypothalamus

Things that result from hormonal changes:

Things that cause hormonal changes:

Hormone: Cortisol

It’s released by your hypothalamus gland in high stress situations. The cortisol in your body causes you to get a quick boost of energy!

(This is good in danger situations) but if you’re stressed all the time, your body will eventually run out of cortisol. This leaves you feeling

exhausted and apathetic.

Background: Stress & Behavior Stress causes chemical changes in your body. Those chemical changes can impact your behavior. For instance, the hormone

called cortisol is released in high-stress situations. It gives you an energy boost, but it also increases feelings of anxiety and fear. It might also make you angry or more aggressive. - Why does it do

these things? Because cortisol exists in order to protect you from danger. The effects created by cortisol are known as the "fight or flight" response. Fear and extra energy help you flee from danger. Anger and aggression help you fight the danger. Problematically,

your body reacts in pretty much the same way in all stress situations, so whether there is a dangerous predator or a

deadline approaching, your body will respond by releasing the same chemicals. These are the four main behavioral effects of

stress: anxiety, anger, depression, and addiction (people develop addictive behaviors as a way of coping with their stress).

Hormone: Cortisol

Video

Hormone: Oxytocin

This hormone is nicknamed “the love hormone” because whenever you touch someone (even when you hug a friend!), it is released into your body generating feelings of pleasure. High levels can increase sex drive, increase trust between

people, allow people to bond with each other, and lower stress.

Not having enough oxytocin released as a child leads to

lower social skills in the future. Oxytocin level is closely linked to social functioning, and some

people inherit a gene that makes their oxytocin levels

naturally higher.

Hormone: Estrogen

Women have more estrogen then men do, because the ovaries produce it in great quantities. The amount of estrogen in a woman’s body changes throughout the month, or throughout the different

phases of her menstrual cycle. At times, it causes irritability, migraines, depression, and PMS.

As teenagers, men have low levels of estrogen

and high levels of testosterone. As they

age, the level of estrogen increases, which can

cause changes in mood and personality.

Hormone: Testosterone Men have more testosterone then women do, because the

testicles produce it in great quantities. Men produce about 20 times more testosterone each day than women. In both, it increases

sexual desire, muscle strength, bone density, and metabolism. If you don’t have enough in your body, it can leave you sluggish,

depressed, unfocused, and disinterested. If you have too much, it can increase aggressive behavior.

Documentary: Oxytocin Points to pay close attention to in this video…

1. Oxytocin is released with physical contact, and it allows us to bond with each other. Specifically, husband and wife bonding; parent and child bonding.

2. Prairie Vols are rodents that “mate for life,” and they have higher levels of oxytocin than other mammals that don’t mate for life.

3. Babies that don’t get enough physical contact will have underdeveloped oxytocin systems, and may show anti-social behavior and anxiety as adults.

4. Study: mice injected with oxytocin from a young age were less likely to become addicted to drugs and alcohol.

5. Study: mice injected with oxytocin and then given alcohol did not show signs of being drunk.

6. Study: rats addicted to methamphetamine became less addicted when injected with oxytocin.