The Brain

There are many different structures and areas inside the brain. I will discuss four of them with you. They are the thalamus, hypothalamus, endocrine and limbic systems. In this paper I will discuss the location of each structure in the brain, its functions, and disorders/pathology related to damage to these structures.

We begin with the thalamus; the thalamus is a mass of nerve cells centrally located in the brain just below the cerebrum and resembles a large egg in size and shape. It consists of a subcortical structure. The thalamus receives and passes on all of the sensory impulses except those of smell, transmitting them to higher nerve centers, such as the cerebal cortex. In addition, it connects various brain centers with others. "Cerebrovascular accidents or strokes can cause thalamic syndrome, which results in a burning or aching sensation on one half of a body, often accompanied by mood swings" (Wikipedia, 2005).

Next, is the hypothalamus. The hypothalamus is an important supervisory center in the brain, rich in ganglia, nerve fibers, and synaptic connections. It is made up of several sections called nuclei, each of which controls a specific function. The hypothalamus regulates body temperature, blood pressure, heartbeat, metabolism of fats and carbohydrates, and sugar levels in the blood. Some neurons in the hypothalamus control arousal, emotions, food and water intake or hunger and thirst, sexual behavior, and temperature. Through direct attachment to the pituitary gland, the hypothalamus also controls water balance and milk production in the female. Furthermore, it is the intermediary link between the nervous system and the endocrine system by "synthesizing and secreting neurohormones" (www.wikipedia.org). A few of them would be, thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH), growth hormone-releasing hormone (GHRH), corticotropin-releasing hormone (CRH), somatostatin and dopamine. The neurons that secrete GnRH are linked to the limbic system; the limbic system is the part of the body that controls emotions and sexual activity.

Next we discuss the endocrine system. According to our text book, "Psychology", by David and Palladino, the endocrine system is defined as a "system of glands that produce and secrete chemicals called hormones that can have effects some distance from the gland that secreted the hormone". These hormones circulate within the body via the bloodstream to affect distant organs. Some of the major endocrine glands are the pineal gland, the pancreas, and the thyroid gland. The pineal gland is located in the depts. Of the brain and produces the hormone called, melatonin. Melatonin acts as a regulator of the sleeping cycle so at night, this hormone is more present. The pancreas is near the stomach and small intestine is very important because it secretes insulin. Insulin helps the cells in the body use glucose so without insulin, the cells don't get enough nourishment. The common disease diabetes is caused by the pancreas not producing insulin and can be very serious is not treated. Lastly, the thyroid gland is located right below the larynx. This gland secretes a hormone, called thyroxin, which controls growth and metabolism. Many people that have a hard time losing weight have hypothyroidism, which is caused by not enough thyroxin. On the other hand, hyperthyroidism, which is too much thyroxin, results in people that are hyper-active, can't