Endocrine SystemMr. Chapman

Biology 30Stolen from future Mrs. Chapman

What is the Endocrine System?

The endocrine system helps the body grow, develop and maintain homeostasis.

The endocrine system makes chemicals called hormones that act to maintain homeostasis.

Hormones are made by organs known as glands.

Endocrine System Details As hormones move through the body

they will be in contact with many cells, however they will only interact with specific cells that have the proper receptor.

Cells that have the correct receptors are called target cells.

Categories of Hormones There are two categories

of hormones:› Steroid hormones› Non-steroid hormones

ALL steroid hormones are made from cholesterol, which is a lipid.

Hypothalamus The hypothalamus acts

as a connection between the CNS and the endocrine system.

The hypothalamus is located at the base of the brain.

Hypothalamus As part of the CNS the hypothalamus

receives, interprets, and sorts information from the sensory organs.

As part of the endocrine system, the hypothalamus produces releasing hormones.

Hypothalamus: “Call me Master”

The hypothalamus is known as the master control center of the endocrine system.

› Its endocrine signals directly control the pituitary gland which secretes hormones that will influence body functions.

Hypothalamus releases TRH in response to cold exposure, which stimulates the pituitary to release TSH.

TSH is called thyroid-stimulating hormone. Thyroid is stimulated to release thyroxine.

Thyroxine is released into the blood where it increases the metabolic rate of body cells, thereby warming the body.

Warmth of body ends stimulation of hypothalamus, halting the cycle.

See how the hypothalamu

s controls EVERYTHIN

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Pituitary Gland The pituitary gland is actually an

extension of the hypothalamus, which consists of an anterior and posterior lobe.

The Thyroid Gland The thyroid gland helpsto regulate developmentand metabolism.

The thyroid and parathyroid gland maintain calcium homeostasis by

regulating the hormone calcitonin.

Adrenal Glands The adrenal glands, which are located

on top of the kidneys, produce hormones that enable the body to respond to stress.