Question

Decide on either the nervous system or the endocrine system for your report.

Write about some disease or condition that is new to you and add some personal comments.

1. Submit your report

2. Participate in the Discussion

Answer 1

1.The endocrine system is one of the two systems that are responsible for communication and integration between various body tissues, the other being the nervous system. Endocrine communication is achieved by means of chemical messengers called 'hormone'.Hormones are produced in endocrine glands and secreted into the bloodstream to reach body tissues. A hormone can travel where the blood goes, but it can only affect cells that have the receptors for it. These are called 'target cells'.There are two major types of hormones-
1.Steroids hormones derived from cholesterol and are lipid soluble
2. Non steroid hormones derived from peptides or amino acids and are water soluble.
Lipid soluble steroid hormones can cross the cell membrane to bind to their receptors inside the cell either in the cytoplasm or nucleus. Steroid hormone receptors are typically transcription factors. Upon forming the hormone receptor complex, bind to specific DNA sequences to regulate gene expression and thus mediating cellular response. On the other hand, water soluble non steroid hormones are unable to cross the lipid membrane and therefore must bind to receptors located on the surface of the cell. The binding triggers a cascade of events that leads to production of cyclic AMP as second messenger that is responsible for cellular response to hormone. It does so by changing enzyme activity or ion channel permeability.Major endocrine glands include the hypothalamus l, pituitary gland, pineal gland, thyroid gland and parathyroid gland, thymus, adrenal glands, islets of pancreas and testis in men, ovaries in women.The endocrine system also includes hormone secreting cells from the other organ such as kidneys and Intestine except for the hypothalamus and pituitary.Different endocrine glands are involved in different more or less independent processes.For example the pancreas produces insulin and glucagon that keep blood sugar level.In the parathyroid glands produce hormones that regulate calcium and phosphorus.Thyroid hormones control metabolic rates while the ovaries and testes are involved in reproductive functions.On the other hand the hypothalamus and pituitary gland play a more Central integrative role. The hypothalamus is also part of the brain that secretes several hormones called 'neurohormones' which control the production of other hormones by the pituitary.Thus the hypothalamus links the nervous system to the endocrine system.The pituitary is known as the master gland because it control the functions of many other endocrine glands.A major role of the endocrine system is to maintain the body's stable internal conditions or homeostasis such as blood sugar levels or serum calcium levels. To do this it utilizes negative feedback mechanism which work very much like a thermostat.The heater is on when the temperature is low, off when it's high. For example when blood glucose level is high after a meal, glucose induces insulin release from the pancreas.Insulin helps body cells consume glucose clearing it from the blood. Low blood glucose can no longer act on the pancreas which now stops releasing insulin.Another example is the regulation of thyroid hormone levels which are induced by pituitary hormone called thyroid stimulating hormone TSH. TSH in turn is under control of thyrotropin-releasing hormone TRH from the hypothalamus.When thyroid hormone levels are too high they suppress the secretion of TSH and TRH, consequently inhibiting their own production.

2.

1.Polycystic Ovary Syndrome (PCOS):  Endocrine system produces more androgenic hormones which interferes with the normal function of ovaries.The symptoms of PCOS are infrequent menses, male pattern hair growth in women, acne, and infertility. Female patients with PCOS will develop insulin resistance and at risk of developing diabetes. PCOS is a has become the leading cause of female infertility. When progesterone and hormone are off, it could result in ovarian cysts on the ovaries and also create problems with their fertility, menstrual cycle, appearance, and cardiac function.

Low levels of the sex hormones in women with PCOS they tend to take on male features including:

1. A deeper voice
2. Small breast
3. Hair on the chest, face, and stomach
4. Acne
5. A gain in weight
6. Pain in the pelvic area
7. Infertility
8. Depression or anxiety

2. Thyroid Cancer

Thyroid cells start to grow out of control and the cells change creating a tumor. A tumor is benigN or malignant (cancerous) that spread throughout the body.

Symptoms

• Lump in neck
• Voice changes
• Swollen lymph nodes
• Throat and neck pain

3.Multiple endocrine neoplasia I and II (MEN I and MEN II).

Genetic conditions are passed down through families causing tumors of the parathyroid, adrenal, and thyroid glands.This to overproduction of hormones.