All the organs in the endocrine system are glands. They are unique from other glands, because they release chemicals known as hormones into general circulation. Other glands discharge their secretion into ducts to a particular place. These glands are called exocrine. The organs of the endocrine system are located in widely separated parts of the body: in the cranial cavity, in the neck, in the thoracic cavity, in the abdominal cavity, in the pelvic cavity, and outside the body cavities. The hormones they release are important to body functions. They regulate basic drives and emotions, such as sexual urges, violence, anger, fear, joy, and sorrow. They also promote growth and sexual identity, control body temperature, assist in the repair of injured tissue, and help to generate energy.
The Pituitary Gland is located in the cranial cavity connected to the hypothalamus of the brain by a slender stalk called the infundibulum. This gland is also known as the "master gland", since it can act on other glands to stimulate action. It has two parts the anterior pituitary (adenohypophysis) and the posterior (neurohypophysis).
The anterior pituitary secretes the human growth hormone whose major effect is on the long bones. It also speeds up the cell's anabolism of amino acids, which results in formation of tissue proteins.
The Prolactin-lactogenic hormone functions in the pregnant woman to prepare the mammary glands for milk production. After delivery, the suckling infant stimulates the continuation of the production of milk. The actual release of the milk is by Oxytocin which is secreted in the posteror pituitary.
Thyroid Stimulating Hormone (TSH) acts on the thyroid gland to increase thyroid homone secretion. This hormone operates on the negative feedback system.
Follicle Stimulating hormone (FSH) Stimulates the growth of the graafian follicle that leads to ovulation in the female. In the male, FSH assists to the development of the sperm cell.
Luteinizing hormone(LH) Initiates ovulation and release of the egg-followed by the formation of the corpus luteum (yellow body)which in turn produces the hormones estrogen and progesterone.
The posterior pituitary releases two hormones which originates in the hypothalamus and is stored there.
Oxytocin - promotes the release of breast milk, as well as stimulates contractions. It is used clinically to induce labor , and to increase uterine tone which prevents hemorrhage immediately after delivery.
Antidiuretic hormone (ADH), also called vasopressin. this causes the kidneys to conserve body water by decreasing the amount of urine produced. It also causes constriction of the arterioles which results in an increase in blood pressure.
GLANDS AND THEIR DISORDERS
The THYROID GLAND is vascular and located in the anterior portion of the neck. This gland plays a major role in regulating the body's rate of metabolism; growth & development; activity of the nervous system and works in conjunction with other systems to control body temperature, metabolic rate, and energy level (just to mention a few of it's many functions. When the metabolic rate falls the hypothalamus steps in and stimulates the pituitary gland to secrete TSH.
Disorders of the thyroid gland result in hyperfunction and hypofunction or simple enlargement of the gland.
Hyperthyroidism also known as GRAVES disease, toxic goiter and thyrotoxicosis. The condition is characterized by excessive output of thyroid hormones.
Graves disease is more prevalent in women 30-40 years of age. There is an intolerance to heat as well as a significant weight loss despite an increased appetite and food intake. Tachycardia is present with an increase in the systolic blood pressure.
Visual problems include exophthalmos (bulging eyeballs), changes in vision and eyelid retraction. The GI system can show an increase in peristalsis leading to diarrhea. There are mood fluctations as well as the possibility of amenorrhea.
Medically, the treatment would be a thyroidectomy for CA of the thyroid. Medically the MD would also reduce or destroy thyroid tissue by irradiation of the thyroid gland with radoactive iodine, eventually resulting in a hypothryoid state. In addition, after the thyroidectomy, the patient would be on antithyroid medications.
Potential complications include thyroid storm. This may occur after surgery or treatment with radioactive iodine. Signs and symptoms to look for include an increase in systolic BP, tachycardia, fever, increased agitation, anxiety, and GI symptoms.
This condition is characterized by a slow deterioration of thyroid fnction. It occurs primarily in older adults and approxinately 5 times more frequently in women than in men.
This patient will present with extreme fatigue and apathy, menstrual disturbances, hair loss, brittle nails, and dry skin. The patient may also complain of an intolerance to cold, anorexia, constipation, bradycardia, and weight gain. Lab values will show a decrease in T3 and T4.
Medically, the MD will go with replacement of the thyroid hormone, a low calorie diet to promote weight loss and an decrease in cholesterol intake.
One area the nurse needs to be aware of is in the administration of sedatives and hypnotiocs with caution due to an increase susceptibility. These medications tend to precipitate respiratory depression in the hypothyroid patient.
The Parathyroid gland are actually 4 small glands that are located near of embedded in the thyroid gland.
The hormone secreted is parathyroid hormone (PTH), which is primarily involved in the control of serum calcium levels.
The patient will present with a history of problems of calcium metabolism. They will need to be assessed for changes in mental or emotional status as well as have reflexes and neuromuscular responses to stimuli evaluated. Lab results include an evaluation of serum calcium levels.
This condition is characterizerd by an excessive secretion of parathyroid hormone, resulting in hypercalcemia. Decalcification occurs in the bones as the calcium moves from the bones into the serum, resulting in an increase in the serum calcium.
The patient with hyperparathyroidism may present with bone cysts and pathologic fractures and renal calculi. CNS wise the pt will complain of drowsiness, fatigue, and lethargy. With the GI system there may be symptoms of constipation, nausea and vomiting as well as epigastric discomfort. The lab tests will show an increase in serum calcium.
The treatment of this patient depends on the cause and overall condition of the patient. It can range from the surgical removal of the parathyroid gland, to simpling decreasing the level of circulating calcium by the use of a loop diuretic (i.e. HCTZ) which increases the circulating volume to dilute the calcium.
Nursing care for this patient would be the same as for a thyroidectomy patient.
This condition is characterized by a decrease in parathyroid hormone (PTH), resulting in hyocalcemia. Severe hypocalcemia results in tetany.
Hypoparathyroidism may occur with the inadvertent removal or the parathyroid gland during thyroidectomy or radical neck dissection. The pt may present with muscle weakness and cramps, numbness and tingling around the lips and in the hands and feet.
Acute tetany can be potentially fatal since is causes bronchospasm, laryngospasm, and seizures.
The treatment would be oral calcium as well as high doses of vitamin D to enhance calcium absorption. There also needs to be an increase of calcium in the diet.
The pancreas is located in the upper left aspect of the abdominal cavity.
The pancreas produces the enzymes, trypsin, amylase, and lipase which are secreted into the duodenum and are necessary for the digestion and absorption of nutrients.
Located within the pancreas are the Islets of Langerhans which contain beta cells; these cells are responsible for the production of insulin. Insulin is necessary in maintaining adequate carbohydrate metabolism.
DISORDERS OF THE PANCREAS
DM is a complex, multisystem disease characterized by the absence or of a severe decrease in the production of insulin.
The primary function of insulin is to facilitate utilization of carbohydrates, thereby controlling the blood glucose level. Insulin is secreted by the beta cells in the islets of Langerhans in the pancreas. The body uses carbohydrates for energy.
If carbohydrates are not available to be utilized for energy, then the cell will begin to break down the fats and protein stores. Breakdown of the fat results in the production of ketone bodies. Protein is wasted during insulin deficiency.
When the circulating glucose cannot be utilized for energy, the level of the serum glucose will increase resulting in hyperglycemia.
There are different classifications of diabetes:
Type I diabetes
This is characterized by beta cell destruction which usually results in absolute insulin deficiency. The onset is frequently in early childhood, most often before the age of 15 (This was formerly known as juvenile diabetes). The individual with Type I diabetes will remain this way for the rest of their life and will require insulin injections for the control of their blood sugar.
Type II diabetes
This is produced by an insulin deficiency caused by defects in insulin production, or by excessive demands for insulin. The pt may or may not be dependent on insulin administration for survival.
The onset of Type II is predominately in adults over the age of 40, but it may occur at any age(it was previously knowns and adult onset diabetes (AODM)). It is associated with obesity, since the majority of overweight people require more insulin. The Type II pt may require insulin for control.
The common signs and symptoms of diabetes include the "3P's": Polyphagia, Polydipsia, and Polyuria. Additional signs and symptoms include fatigue, increased frequency of infections, on at least two occassions the pt has a fasting blood glucose of 126mg/dL. Finally the urine is positive for glucose and ketones.
S&Sx specific to Type I include: weight loss, excessive thirst, bed wetting. The onset is generally rapid over days to weeks.
S&Sx of Type II are: weight gain (obese), visual disturbances with a slow onset that may occur over months. Some of the classic signs may be overlooked as signs of aging.
Treatment can be done with various modalities to include: Medications: insulin (primary function is to transport glucose into the muscle and fat cells).In addition to insulin oral hypoglycemics can also be administered.Medication interactions and diabetic control with the use of diuretics, glucocorticoids, and beta-blockers may cause hyperglycemia.
Exercise - needs to be planned, not sporadic (REMEMBER: The metabolic effects of exercise...Reduces insulin needs which results in an increased utilization of glucose-->less extreme fluctuation of glucose levels).
Diabetic diet to decrease calories for weight loss and to meet the nutritional needs and maintain optimum glucose level.
It is important to give the diabetic patient very specific written guidelines regarding exercise. The patient must understand that exercise will reduce the need for insulin; dosages must be calculated according to specific need.
COMPLICATIONS OF INSULIN THERAPY
The major complications include hypoglycemia, lipodystrophy (tissue atrophy and hypertrophy). Lipodystrophy is associated with administration of cold insulin and poor rotation of injection sites. Injection of insulin into lipodystrophic tissue may result in poor absorption of the insulin, requiring increased dosages.
COMPLICATIONS ASSOCIATED WITH POORLY CONTROLLED DIABETES
One of the major complications is diabetic ketoacidosis (DKA). this is a severe increase in the hyperglycemia state and occures predominately in Type I (IDDM).
DKA signs and symptoms may be acute or can occur over several days. This can result from stress, infection, surgery, or lack of effective insulin control. Other symptoms include severe hyperglycemia (300 mg/dL or greater), metabolic acidosis, an increase in urine ketones and sugar, excessive weakness and increased thirst, abd pain, N/V, fruity (acetone) breath and Kussmauls respirations. As it progresses there will be a decreased LOC, an increased temperature due to dehydration and hyperkalemia. This can be a life threatening situation that the nurse and physician need to be made aware of immediately.
COMPLICATIONS OF LONG TERM DIABETES
These will include angiopathy, PVD, eye disorders (blurred vision, retinopathy, cataracts), Nephropathy (often leading to renal failure), infections, and peripheral neuropathy (may cause general pain and tingling; may progress to painless neuropathy. REMEMBER: painless peripheral neuropathy is a very dangerous situaton for the diabetic. Severe injury may occur to the lower extremities and the client will not be aware of it. Clients must be taught to VISUALLY inspect their feed and legs.
HYPOGLYCEMIA (INSULIN REACTION)
Hypoglycemia is a condition characterized by decreased serum glucose levels, which in turn results in decreased cerebral function.
The hypoglycemic patient will experience mood lability, confusion, headache, impaired vision, tachycardia, nervousness, tremors, and diaphoresis. Lab work will show a serum glucose below 50mg/dL and a negative urine acetone.
The treatment for this is to administer carbohydrates by mouth if pt is awake. Administer simple sugars (OJ, honey, candy), but if client does not eat within 1-2 hours, it needs to be followed up with complex carbohydrates like milk, cheese, and crakers.
If the client is unconscious, report it immediately and prepare to give glucagon.
When in doubt of diagnosis of hypoglycemia versus hyperglycemia, administer carbohydrates. Severe hypoglycemia can result in permanent brain damage.