The Endocrine System

•The Endocrine System are the glands that secrete hormones into the bloodstream

Endocrine System

• One of the body’s two communication systems–Nervous and endocrine

• A set of glands that produce hormones-- chemical messengers that circulate in the blood

Hormone• Chemical messengers produced by

the endocrine glands and circulated in the blood

• Similar to neurotransmitters in that they are also messengers

• Slower communication system, but with longer lasting effects

Endocrine System

Hypothalamus

•Brain region that controls the pituitary gland

•Controls homeostasis – the bodies ability to remain at a status quo level

Pituitary Gland• The endocrine system’s gland

that controls the other endocrine glands

• Called the “master gland”• Located at the base of the brain

and connects to the hypothalamus

Pituitary Gland

• Controls thirst by controlling the amount of water in the body’s cells

• Controls female contractions, and tells the mammary glands to produce milk for newborns

Pituitary Gland

• May control grooming habits, companionship, and sexual behavior

• Controls the flow of the human growth hormones – dwarfism and gigantism

Pineal Gland• Responsible for the hormone

“Melatonin”• Increased levels of Melatonin

cause behaviors associated with sleep

• Decreased levels of Melatonin cause behaviors associated with wakefulness

Thyroid Gland• Endocrine gland that helps

regulate the energy level in the body

• Located in the neck

Endocrine System

Thyroid Gland• controls body temperature • Controls metabolism – our body’s

ability to transform the food we eat into usable energy

• Overactive? Behaviors may include excitability, insomnia, ADD, agitation, difficulty focusing

• Reduced Activity? Behaviors may include sleepiness, reduced muscle tone, overweight

Adrenal Gland

• Endocrine glands that help to arouse the body in times of stress

• Located just above the kidneys• Release epinephrine (adrenaline)

and norepinephrine (noradrenaline)

Endocrine System

Adrenal Glands

• Increase heart rate, blood pressure, and blood sugar

Pancreatic Gland

• Regulates the level of blood sugar (insulin) in the blood

Endocrine System

Pancreas

• Insulin is needed in the body to break down sugars in the body

• Too much insulin in the body devours all of the sugar in the blood. Behaviors exhibited include sluggishness and inattentiveness.

• Too little insulin causes a buildup of sugar in the blood and makes the kidneys use a lot more water to flush it out of the body. The extra water needed to flush the sugar comes from surrounding cells, which in turn dehydrates them and leaves them vulnerable to infection and poisons.

Sex Glands

• Ovaries (females) and testes (males) are the glands that influence emotion and physical development.

• Testosterone – primary males hormone• Estrogen – primary female hormone• Males and females have both estrogen

and testosterone in their systems.

Endocrine System

Gonads

• Testicles – release androgens (male hormones)

• Ovaries – release estrogens (female hormones)

• The presence of these chemicals influence male and female reproductive characteristics.