Chapter 14: Endocrine System

mineralocorticoids

(water/fluid balance) Principal one is aldosterone. Principal action is to help regulate Na+ and K+ levels in the blood. Increase the reabsorption of Na+ - Increases fluid retention. Helps regulates blood volume and BP.

adren/o

adrenal gland

prediabetes

an individual is diagnosed with prediabetes if blood glucose levels are higher than normal, but not high enough for a diagnosis of Type 2 diabetes

calc/o

calcium

diabetes mellitus (DM)

can be either a deficiency of insulin in the blood or a deficient carbohydrate metabolism. Both variations are characterized by potentially life-threatening elevated blood glucose

hypoparathyroidism

deficient parathyroid hormone production—results in tetany (continuous muscle spasms), as well as hypocalcemia, irritability, and muscle cramps. The accompanying photographs demonstrate signs of tetany

hypophysis/o

hypophysis gland

dopamine

increases blood pressure and heart rate, dilates arteries, and increases the production of urine

Addison disease

insufficient secretion of adrenal cortisol from the adrenal cortex manifested by gastric complaints, hypotension, fatigue, and hyperpigmentation of the skin and mucous membranes

anorexia

lack of appetite

hypoglycemia

low glucose levels

hormone test

measure the amount of ADH, cortisol, growth hormone, or parathyroid hormone in the blood

total calcium test

measures the amount of calcium in the blood, particularly relevant in determining parathyroid function

tetany

muscle spasms

hormone

or chemical messengers, within the body. The word hormone is from the Greek hormaein, meaning to excite, arouse, or set in motion. As signaling chemicals, then, hormones influence and regulate other bodily processes.

hyperinsulinism

oversecretion of insulin, can result in two challenging disorders

pancreat/o

pancreas

adrenal cortex

releases three hormones: mineralocorticoids, to regulate blood volume, pressure, and electrolytes; glucocorticoids, to respond to stress and contribute antiinflammatory action; and the sex hormones, to provide secondary sex characteristics

radioactive iodine uptake (RAIU)

scans can test thyroid function by measuring the gland's ability to concentrate and retain iodine. In hyperthyroidism, absorption of iodine is increased. Its uptake is visualized in an image produced by a thyroid scan

glands

secrete chemical messengers, called hormones, into the circulatory system's bloodstream to arouse or set in motion a number of physiologic processes, including metabolism, growth, reproduction, and water and electrolyte balances

triiodothyronine (T3)

secretion of thyroid gland has 3 atoms of iodine

esthesi/o

sensation

pituitary growth hormone PGH

stimulates body, bone and muscle to grow (whole body)

endocrine system

system works with other body systems to keep the body functioning as an integrated whole. This system is made up of glands (aden/o) that secrete chemical messengers, called hormones, into the circulatory system's bloodstream to arouse or set in motion a number of physiologic processes, including metabolism, growth, reproduction, and water and electrolyte balances

radioimmunoassay studies (RIA)

tag and detect hormones in the blood and are used to detect pituitary dwarfism (shown here) among other disorders

pineal gland

the gland that plays a major role in sexual development, sleep, and metabolism

ketonuria

the presence of ketones in urine. Unfortunately, this increases the acidity of the blood, a potentially dangerous condition. Because the cells cannot use glucose in the absence of insulin, they turn to fat as a source of energy. When fat breaks down, it produces ketones as a by-product. If ketone acids appear in excess in the bloodstream, the condition is called ketoacidosis

endocrinology

the study of the endocrine glands

metabolism

the sum total of all the chemical processes that take place in the human body, including the distribution of nutrients within the body, the generation of energy, and the elimination of wastes. They help to maintain homeostasis, the stability of the body's internal environment

parathyroid gland

there are usually four of these. They produce hormones which regulate concentration of blood calcium & phosphorus.

thym/o

thymus gland

parathyroid/o

thyroid gland

thyr/o thyroid/o

thyroid gland

sex hormones

to provide secondary sex characteristics

glucocorticoids

to respond to stress and contribute antiinflammatory action

-crine

to secrete

trop/o

turning

thyroid carcinoma thyrocarcinoma

two most common forms of thyroid carcinoma—follicular and papillary—have high five-year survival rates. Thyroid carcinoma is also referred to as thyrocarcinoma

Type 1 diabetes insulin- dependent diabetes mellitus (IDDM)

usually has its onset during childhood and involves a deficiency of insulin in the body. It produces symptoms of polydipsia, polyuria, blurred vision, fatigue, frequent infections, and polyphagia

gestational diabetes

develops in some women during pregnancy because hormonal changes related to the pregnancy can cause insulin resistance. Typically, this condition resolves after childbirth but, in a number of cases, recurs years later as Type 2 diabetes. Finally, an individual is diagnosed with prediabetes if blood glucose levels are higher than normal, but not high enough for a diagnosis of Type 2 diabetes

myxedema

By contrast, hypothyroidism, which is called myxedema in its extreme adult form, is a deficiency of thyroid hormone production

epinephrine adrenaline

dilates bronchi, increases heart rate, raises blood pressure, dilates the pupils, and elevates blood sugar

malignant thymoma

does occur, but rarely. rare cancer of the thymus gland

growth hormone (GH)

GH also promotes the synthesis of proteins, performs cell repair, and helps to maintain blood glucose levels. For certain treatments, growth hormone has sometimes come from artificial sources; for that reason institutions will sometimes specify human growth hormone specifically with the abbreviation hGH. Similarly, pituitary growth hormone can be specifically designated by the abbreviation PGH

thymus gland

Gland located near the heart; produces several hormones which stimulate development of cells important in immmunity Hormones from this gland help the immune system develop during childhood

endocrine gland

Hormones from endocrine glands are secreted directly into the bloodstream through the glandular membrane without the use of ducts

glucosuria glycosuria

excessive glucose in the bloodstream

gigantism

excessive growth caused by hypersecretion of somatotropin from the adenohypophysis during childhood

hypokalemia

excessive potassium in the bloodstream

Cushing disease

excessive secretion of cortisol by the adrenal cortex. Symptoms include obesity, leukocytosis, hypokalemia, hyperglycemia, muscle wasting, and hirsutism

polydipsia

excessive thirst

polyuria

excessive urination

thymoma

found in association with myasthenia gravis Malignant tumor of the thymus gland.

Pheochromocytoma

Pheochromocytoma is a benign tumor of the adrenal medulla that causes oversecretion of epinephrine and norepinephrine. The name of this tumor comes from its dark color: phe/o = dark; chrom/o = color; cyt/o = cell

somatotropin (STH)

gland- pituitary anterior lobe; aka growth hormone

aden/o

glands

hyperglycemia

high glucose levels

thymosin

hormone called thymosin to stimulate cells involved in the immune response; produced by the thymus gland

human growth hormone hGH

hormone produced by the pituitary gland; stimulates cell reproduction and growth

thyroid gland

SECRETES CALCITONIN WHICH PREVENTS CALCIUM RELEASE FROM THE BONE? regulates metabolism, growth, and development through the hormones triiodothyronine, or T3, and tetraiodothyronine, also called thyroxine or T4. It also regulates the amount of calcium (calc/o) in the blood through t

antidiuretic hormone (ADH)

The hormones secreted by the posterior lobe—antidiuretic hormone (ADH) and oxytocin (OT)—are produced in the hypothalamus. ADH stimulates the kidneys to reabsorb water and acts also as a vasoconstrictor, raising blood pressure.

oxycotin (OT)

The hormones secreted by the posterior lobe—antidiuretic hormone (ADH) and oxytocin (OT)—are produced in the hypothalamus. Oxytocin stimulates the uterus during delivery and the muscles around the mammary ducts to stimulate lactation

islets of Langerhans

The islets of Langerhans cells fall into two types: alpha and beta. Alpha cells produce the hormone glucagon to increase blood glucose levels; beta cells secrete insulin, which moves fatty acids, amino acids, and glucose out of the blood and into the tissues

syndrome of inappropriate antidiuretic hormone (SIADH)

The opposite of diabetes insipidus is the oversecretion of ADH, or syndrome of inappropriate antidiuretic hormone (SIADH), which leads to the inability to excrete diluted urine. Larry does not have either of these disorders, exactly, but Dr. Payne suspects Larry has something similar to diabetes insipidus—as we'll soon see

exocrine gland

There are two types of glands, each categorized by how it releases its secretions. Sweat glands, for example, are exocrine glands; they secrete their substances into ducts that lead to their target organs or are excreted from the body (exo- = outward)

Graves disease

A common diagnostic sign is ketoacidosis, and its most common form is Graves disease. This form can be accompanied by a lack of appetite, called anorexia, and/or exophthalmia, a protrusion of the eyeballs from their orbits. By contrast, hypothyroidism, which is called myxedema in its extreme adult form, is a deficiency of thyroid hormone production. In childhood, it can cause cretinism, a suppression of mental and physical growth.

panhypopituitarism Simmonds disease

A deficiency or lack of all pituitary hormones is called panhypopituitarism, or Simmonds disease, which causes hypotension, weight loss, weakness, and loss of libido

pituitary gland hypophysis gland

A gland that controls growth; considered to be the master gland because it controls the functions of other endocrine glands. This tiny gland, located behind the optic nerve in the cranial cavity, is divided into anterior and posterior lobes, seen here

melatonin

A hormone manufactured by the pineal gland that produces sleepiness

calcitonin

A hormone produced by the C-cells of the thyroid gland that decreases serum calcium levels. It targets teh bones (stimulates osteoblasts), the kidneys (reduces calcium reabsorption), and the small intestine (decreases calcium absorption).

adrenal gland

A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

hyponatremia

Abnormal condition of low sodium in the blood

hirsutism

Abnormal hairiness, especially in women

ketoacidosis

Acidosis accompanied by an accumulation of ketone in the blood resulting from faulty carbohydrate metabolism

pancreas

An organ of the digestive system that produces a fluid that neutralizes stomach acid and chemicals that help finish digestion.

diabetes insipidus (DI)

Do you remember when Larry complained of excessive thirst followed by excessive urination? Both of these symptoms can be indications that a patient has diabetes insipidus (DI), a deficiency of antidiuretic hormone (ADH), which is normally secreted from the neurohypophysis. This deficiency causes the patient to excrete large quantities of urine (polyuria) and have excessive thirst (polydipsia)—two major symptoms our patient Larry complains of. The opposite of diabetes insipidus is the oversecretion of ADH, or syndrome of inappropriate antidiuretic hormone (SIADH), which leads to the inability to excrete diluted urine. Larry does not have either of these disorders, exactly, but Dr. Payne suspects Larry has something similar to diabetes insipidus—as we'll soon see

goiter

Enlargement of the thyroid gland

hyperparathyroidism

Excess or deficient parathyroid hormone also presents serious problems. First, hyperparathyroidism—the overproduction of parathyroid hormone—induces polyuria, hypercalcemia, hypertension (abnormally elevated blood pressure), and kidney stones. On the other hand,

polyphagia

Excessive eating

hyperthyroidism

Excessive thyroid hormone production is called

thyrotoxicosis

Excessive thyroid hormone production is called hyperthyroidism or, at its most severe, thyrotoxicosis

prolactinoma

In addition to hormonal disturbances, the pituitary gland can also be subject to tumors, such as the common benign tumor prolactinoma, which causes the pituitary to oversecrete prolactin (PRL)

drug replacement

In some cases, pharmacologic interventions can correct imbalances by either inhibiting or replacing abnormal hormone levels. Addison disease, hypothyroidism, hyperthyroidism, and diabetes are examples of disorders that may be treatable with drug interventions. Dr. Payne prescribes an oral antidiabetic agent to control of Larry's diabetes. For those patients needing insulin replacement therapy to compensate for impaired pancreatic functioning, insulin is available in injectable or inhalation formulations, or can be delivered to the body by an insulin pump, demonstrated in the illustration. Notice that this device is worn externally and connected to an indwelling subcutaneous needle

islet cell carcinoma

In the pancreas, the islet cell carcinoma is the fourth leading cause of cancer death in the United States (carcin/o = epithelial cancer).

adenohypophysis

Made up of glandular tissue, the anterior lobe, or adenohypophysis, secretes a large number of hormones in response to stimulation by the hypothalamus in the brain—either releasing or inhibiting the release of specific hormones and having a wide array of effects on the human body

suprarenals

Sit atop the kidneys. Respond to stress, affect fluid balance, and make a small amount of sex hormones. Hormones include Aldosterone, cortisol, Epinephrine, Norepinephrine, and sex hormones

growth hormone deficiency (GHD)

When the adenohypophysis does not secrete adequate amounts of somatotropin (growth hormone) during childhood, the resulting growth hormone deficiency (GHD) leads to dwarfism

paresthesias

a morbid or abnormal sensation, as burning, prickling, pins and needles, numbness

acromegaly

a result of hypersecretion of somatotropin from the adenohypophysis during adulthood. This leads to an enlargement of the hands, feet, jaw, nose, and forehead

cretinism

a suppression of mental and physical growth

oral glucose tolerance test (OGTT)

a three-month analysis of average blood glucose used to monitor response to diabetes treatment

exophthalmia

abnormal protrusion of the eyeball

neurohypophysis

posterior part of the pituitary gland is called the neurohypophysis. We will look at this part of the pituitary gland; composed of nervous tissue. The hormones secreted by the posterior lobe—antidiuretic hormone (ADH) and oxytocin (OT)—are produced in the hypothalamus. ADH stimulates the kidneys to reabsorb water and acts also as a vasoconstrictor, raising blood pressure. Oxytocin stimulates the uterus during delivery and the muscles around the mammary ducts to stimulate lactation

fasting plasma glucose (FPG)

previously called fasting blood sugar (FBS), measures the body's ability to break down and utilize glucoseoral

Type 2 diabetes non-insulin-dependent diabetes mellitus (NIDDM)

produces similar symptoms. It usually develops in adulthood and involves some insulin deficiency and a loss of the body's ability to respond to the action of insulingest

norepinephrine noradrenaline

raises blood pressure and blood sugar levels and increases heart rate

tetraiodothyronine (T4) thyroxine

regulates the amount of calcium (calc/o) in the blood through the hormone calcitonin

adrenal medulla

releases three hormones. The first, epinephrine or adrenaline, dilates bronchi, increases heart rate, raises blood pressure, dilates the pupils, and elevates blood sugar. The second hormone, norepinephrine, or noradrenaline, also raises blood pressure and blood sugar levels and increases heart rate. The third hormone, dopamine, increases blood pressure and heart rate, dilates arteries, and increases the production of urine. Do not confuse aden/o, which means gland, with adren/o, which means the adrenal gland

thyroid function test (TFT)

which assesses TSH, T3, T4, and calcitonin levels if desired

parathyroid hormone (PTH)

which increases calcium levels in the blood by causing it to be released from the bone and reabsorbed by the kidneys and digestive system.