Hormones – Part A Reading

Text A

Hormones are chemical messengers that coordinate different functions in your body. Several glands, organs and tissues make and release hormones, many of which make up your endocrine system. In other words, hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, skin, muscles and other tissues. These signals give different commands to your body – what to do and when to do. Hormones are essential for life and health.

Scientists have identified over 50 hormones in the human body so far. Hormones and most of the tissues (mainly glands) that create and release them make up your endocrine system. Hormones control many different bodily processes, including:

Text B

Metabolism, homeostasis (constant internal balance), such as blood pressure and blood sugar regulation, fluid (water) and electrolyte balance and body temperature are all a few major task areas of hormones. Besides, growth and development, sexual function and reproduction, falling asleep and waking cycle and mood are also controlled by hormones. Hormone imbalance is very subtle and complicated topic because, a little variation is hormones have serious consequences. These consequences often require the body undergo repair.

A hormone will only act on a part of your body if it “fits” — if the cells in the target tissue have receptors that receive the message of the hormone. Think of a hormone as a key and the cells of its target tissue, such as an organ or fat tissue, as specially shaped locks. If the hormone fits the lock (receptor) on the cell wall, then it’ll work; the hormone will deliver a message that causes the target site to take a specific action.

Text C

Your body uses hormones for two types of communication. The first type is communication between two endocrine glands: One gland releases a hormone, which stimulates another gland to change the levels of hormones that it’s releasing. An example of this is the communication between your pituitary gland and thyroid. Your pituitary gland releases thyroid-stimulating hormone (TSH), which triggers your thyroid gland to release its hormones, which then affect various aspects of your body.

The second type of communication is between an endocrine gland and a target organ. An example of this is when your pancreas releases insulin, which then acts on your muscles and liver to help process glucose.

Text D

Specialized glands that make up your endocrine system make and release most of the hormones in your body. A gland is an organ that makes one or more substances, such as hormones, digestive juices, sweat or tears. Endocrine glands release hormones directly into your bloodstream.

Your endocrine system consists of the following glands:

• Hypothalamus.
• Pituitary gland.
• Pineal gland.
• Thyroid.
• Parathyroid glands.
• Adrenal glands.
• Pancreas.
• Ovaries.
• Testes.

But not all organs and tissues that release hormones or hormone-like substances are considered part of the endocrine system. Other body tissues that release hormones include adipose tissue (fat tissue), the kidneys, the liver, the gut (gastrointestinal tract), the placenta and the hypothalamus.