C.6.1

=Hormones - production and their roles in the body=

Hormones are chemicals that are produced in glands in the body. They act as chemical messengers and are transported through the body via the bloodstream. They usually are sent from glands to organs and tissue.
 * What are Hormones?**

- Adrenaline - Thyroxine - Insulin - Sex Hormones Testosterone (main male sex hormone) Progesterone and Oestradiol (main female sex hormones)
 * What Hormones do we need to know about?**

Hormones produced is controlled by the **pituitary gland**, which is controlled by the **hypothalamus** in the brain.
 * Where are they produced? What do they do?**



Each of the hormones are produced in different glands in the body:

Produced in the **adrenal glands**, which are above the kidneys.
 * Adrenaline** aka **Epinephrine**



Function - released in times of excitement or stress. (it's sometimes called the fight or flight hormone). Causes a rapid dilation of the pupils and airways, and increases heartbeat and rate of release of sugar in to the blood stream.

Adrenaline does not have the steroid backbone seen in the sex hormones.

__Produced__ - in the **thyroid gland**, in the neck. __Function__ - regulates the body's metabolism / involved in the control of heart rate / involved in temperature regulation. The element iodine is an important element of the diet needed to make thyroxine. Food rich in iodine are shell fish.
 * Thyroxine**

Thyroxine does not have the steroid backbone seen in the sex hormones.

**Insulin**
Insulin is made up of two polypeptides chains held together by disulfide bond. __Produced__ in the **pancreas**, which is in the back of the abdomen. Insulin does not have a steroid backbone. __Function__ - regulates concentration of glucose in the blood. Diabetes results when insulin is not produced in enough quantities to regulate glucose concentration in the blood.

http://www.endotext.org/Diabetes/diabetes3_new/figures3/figure7.gif

Sex hormones
__Called__ - Testosterone __Produced__ - in the testes __Function__ - Encourages tissue, muscle, and bone growth as well as conferring the male characteristics. __Use__ - This hormone can be described to patients who are recovering from injury or severe illness. The hormone increases the rate of protein synthesis helping to increase muscle mass in people who muscles have wasted away because they have been bedridden for a long time. This hormone is banned in sporting events because it unfairly enhances performance because of its ability to increase muscle mass.
 * Male sex hormones**

__Called__ - Oestradiol and Progesterone __Produced__ - in the ovaries __Function__ - Encourages sexual development as well as being responsible for the menstrual and reproductive cycles in women. __Uses__ - 1. Progesterone and oestradiol are found in the oral contraceptive pill. The pill mimics the high hormone levels seen during pregnancy, so that no more eggs are released from the ovary. It prevents the release of the FSH and LH hormones by the pituitary gland needed for ovulation. 2. Progesterone and oestradiol can be prescribed to prevent osteoporosis, a brittle bone disease common in women with low levels of these hormones.
 * Female sex hormones**