Nursing Preparation Study Guide

Nursing Preparation Study Guide o The interior of the adrenal glands – the adrenal medulla – produces epinephrine and norepinephrine (noradrenaline). These hormones prepare the body for either “fight or flight”. § Epinephrine (adrenaline) increases the heart rate and breathing rate, adjusts the blood supply to the extremities, and causes the blood to clot more readily. For example, when you are suddenly startled, you may notice these physiological changes in your body. • Pancreas: The pancreas lies within the abdominopelvic cavity. It is primarily an exocrine organ that makes digestive enzymes. The pancreas contains special endocrine cells called islets of Langerhans. These secrete several hormones: o Insulin: Beta cells produce the hormone insulin. Insulin lowers blood glucose levels by increasing the rate of glucose uptake and utilization by most body cells, and by increasing glycogen synthesis in skeletal muscles and the liver. o Glucagon: Produced by alpha cells. Glucagon raises blood glucose levels by increasing the rates of glycogen breakdown and glucose released by the liver. o The other two hormones, pancreatic polypeptides and somatostatin, assist insulin and glucagon with their actions. • Pineal gland: This gland is located in the epithalamus of the brain. The pineal gland contains neurons, neuroglia, and special secretory cells called pinealocytes. These cells synthesize the hormone melatonin from molecules of the neurotransmitter serotonin. As previously mentioned, melatonin plays an important role in the sleep-wake cycle. In fact, the cause of jet lag is due to melatonin disruption. • Thymus gland: This plays a key role in immunity by helping white blood cells mature. There are also hormones produced throughout other tissues and organs in the body, including erythropoietin from the kidney, which helps to increase the rate of erythrocyte (red blood cell) production. 7.3.3 Common Diseases and Disorders • Cretinism: Caused by a lack of thyroid hormones produced during development. The severe hormone deficiency causes a hard form of edema called myxedema. • Diabetes: Insufficient insulin production leads to diabetes. For those who suffer from type 1 diabetes, the cells in their pancreas have stopped producing insulin or produce very little. Those with type 2 diabetes are able to produce some insulin, but not enough to regulate blood glucose levels due to the cells’ inability to accept glucose. Type 2 diabetes is often seen in obese patients. • Goiter: This is an enlargement of the thyroid gland, often caused by iodine deficiency. • Hyperthyroidism: Caused by too much thyroxin, resulting in a higher than normal metabolic rate. • Hypothyroidism: A lack of thyroxin. • Polycystic ovary syndrome: This is a common female endocrine disorder. Although its causes may be genetic, hormone imbalances are a major factor of this syndrome.

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