26 September, 2012
The endocrine system and the glands that are within it are there to help people become the individuals that they are. Chemical substances are released into the bloodstream from the endocrine glands, these are called hormones. Hormones function as messengers that are also quite similar to neurotransmitters. Norepinephrine can serve as both a hormone and a neurotransmitter. (Maisto & Morris, 2005) There are a few differences between the nervous system and the endocrine system, but the main difference is it takes longer for hormones to take their message where it needs to go than it does the nervous system. Nerve impulses travel through the body at a few hundredths of a second, while hormones may take seconds to up to a few minutes to reach its destination (Maisto & Morris, 2005).
The endocrine system consists of seven glands that secrete hormones. From top to bottom these glands are: pineal gland, pituitary gland, thyroid gland, parathyroid gland, pancreas, adrenal gland, and ovaries in females and testes in males (Maisto & Morris, 2005).
In the middle of the brain, there is a gland that regulates activity levels over the course of the day. This gland is the pineal gland and it secretes melatonin. Melatonin is a hormone that helps to regulate the sleep-wake cycles in a day. “Jet-lag” is caused by disruptions in melatonin production (Maisto & Morris, 2005).
There is a gland on the underside of the brain that is connected to the hypothalamus. This gland is the pituitary gland, also known as “the master gland”. The pituitary gland is produces the largest number of hormones and regulates other endocrine glands. Thirst, blood pressure, contractions of the uterus during childbirth, sexual behavior and interest, milk production, bodily growth, the amount of water cells needed and many other functions are influenced by the pituitary gland (Maisto & Morris, 2005).
Too little thyroxin being produced can result in the need to sleep constantly and still feel tired (Maisto & Morris, 2005). The thyroid gland is responsible for producing thyroxin. The thyroid gland is located below the larynx and regulates how alert and energetic people are. They thyroid gland also regulates how fat or thin people are. Insomnia, over excitement, reduced attention span and acting out of character are all symptoms of an overactive thyroid. There are four glands located within the thyroid gland called parathyroid glands. These glands are responsible for controlling the balance of phosphate and calcium in the body. The parathyroid gland is also responsible for the level of excitability a person experiences (Maisto & Morris, 2005). The gonads secrete different hormones, androgens in males and estrogen in females. The gonads are the female ovaries and the male testes are responsible for the production of these hormones. Males and female produce both hormones, but males produce more androgens and females produce more estrogen. Both estrogen and androgens play a role in human development. According to Maisto & Morris, more testosterone leads to more aggressive behavior in human males between the ages of 15 and 25 years of age. This is when testosterone levels are at their highest (Maisto &