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The Endocrine System

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FunctionsTo control many of the body’s daily activities

Controls the body’s long term changes such as development

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StructuresEndocrine glands – organs that produce and release chemicals directly into the bloodstream

Hormones – the chemicals released by Endocrine glands; can be thought of as chemical messengers

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HormonesAct as internal stimuli that direct the body’s response

Hormones only interact with certain target cells – cells that recognize the hormone

+Hormone Production1.Nerve impulses from your

senses travel to the brain

2.Sound of thunder is interpreted

3.Brain sends nerve impulses to a specific endocrine gland

4.That gland releases the hormone, adrenaline, into the bloodstream

5.Adrenaline causes…1. Increased heart rate2.Breathe faster and deeper3.Release sugar to your muscles

In a Sudden Storm…

+Hormone ProductionHormones cause a slower, but longer-lasting response

When adrenaline reaches the heart, it pumps faster and will continue to do so until the amount of adrenaline goes back to normal

+Structures & FunctionsThe HypothalamusFound in your brain (near

the middle of your head)

Responsible for – controlling sleep, hunger, and other endocrine glands and organs

+Structures & FunctionsThe Pituitary GlandFound below the hypothalamus

Responsible for – regulating body processes like growth, blood pressure, and water balance, and helps control other endocrine glands

+Structures & FunctionsThe Thyroid GlandFound at your neckResponsible for – controlling the release of energy from food molecules

+Structures & FunctionsThe Parathyroid GlandFound at your neckResponsible for – regulating the amount of calcium in the blood

+Structures & FunctionsThe ThymusFound at your chestResponsible for – helping cells in your immune system develop

+Structures & FunctionsThe Adrenal GlandsFound on top of kidneysResponsible for – controlling the water/salt balance in the kidneys, the amount of sugar in the blood, and releasing adrenaline…in response to emergency situations

+Structures & FunctionsThe PancreasFound in front of kidneysResponsible for – produces the hormones, insulin and glucagon, to control the level of sugar in the blood

+Structures & FunctionsThe OvariesResponsible for – produces the female sex hormonesEstrogen controls the changes in a teenage girl’s body

Estrogen and Progesterone trigger the development of eggs

+Structures & FunctionsThe TestesResponsible for – produces the male sex hormonesTestosterone controls the changes in a teenage boy’s body and needed for normal sperm production

+Hormones controls the body’s response in many different situations…In exciting situations,

like roller coastersAs a child grows

older

+Use of Negative FeedbackTemperatur

e is above 78° F

Temperature is above

78° F

Temperature is at 78° FTemperature is at 78° F

STARTSTARTSTOPSTOP

The thermostat signals the

air conditioner to turn on

The thermostat signals the

air conditioner to turn on

The thermostat signals the

air conditioner to turn off

The thermostat signals the

air conditioner to turn off

Negative Feedback is an important way that the body maintains stable internal conditions, or homeostasis.

+Use of Negative FeedbackBlood sugar

level of 170Blood sugar level of 170

Blood sugar level at 95

Blood sugar level at 95

STARTSTARTSTOPSTOP

The pancreas is signaled to

release insulin

The pancreas is signaled to

release insulin

The pancreas is signaled to

stop releasing

insulin

The pancreas is signaled to

stop releasing

insulin

+The Endocrine System