10. Diseases of the Endocrine System

endocrinology

The study of the endocrine system and its disorders

Ductless glands

that secrete hormones directly into interstitial spaces where they’re absorbed into blood

neuroendocrine organs

The hypothalamus and pituitary gland.The hypothalamus links the endocrine system to the nervous system via the pituitary gland.

Thyroid

•secretes thyroid hormones triiodothyronine (T3) and thyroxine (T4) and the peptide hormone calcitonin

Parathyroid

•produces and secretes parathyroid hormone, which helps regulate the amount of calcium in blood and  bones

pituitary gland

located at the base of the brain, at the bottom of the hypothalamus

hypothalamus

controls body temperature, hunger, aspects of parenting and maternal attachment behaviors, thirst, fatigue, sleep, circadian rhythms, and more.

pineal gland

•produces melatonin, a serotonin-derived hormone, which modulates sleep patterns

Adrenal (aka suprarenal) glands

produce three main types of steroid hormones

3 main steroid hormones

•Mineralocorticoids – e.g. aldosterone, help regulate blood pressure and electrolyte balance

•Glucocorticoids – e.g. cortisol and cortisone, regulate metabolism & immune system suppression

•Androgens – male sex hormones

The adrenal medulla produces catecholamines (epinephrine, norepinephrine, and dopamine),

which produce a rapid response throughout the body in stress situations.

Ovaries

produce eggs, and secrete hormones including estrogen, androgen, inhibin, and progesterone.

Testes

produce sperm and secrete androgens like testosterone.

Pancreatic adenocarcinoma

•is the most common cancer of the pancreas. These adenocarcinomas begin in the ductal part of the pancreas that makes digestive enzymes.

Acromegaly

(acro = extremities, megaly = enlargement) A chronic hyperfunction of the anterior lobe of the pituitary gland after ossification is complete (this means it happens in adults)

adenoma

•a benign tumor of the pituitary gland

Hypersecretion

•in children (before the bones have ossified) causes giantism or gigantism.

Hyposecretion

during growth years can lead to dwarfism.

Diabetes Insipidus

•is caused by a disorder between the pituitary gland and kidneys that prevents the kidneys from preserving water

goiter

swelling of the neck caused by an enlarged thyroid. (Thyroid malfunction (hyper or hypo)

athyreosis

(complete lack of a thyroid gland), physical features may include a larger anterior fontanel, persistence of a posterior fontanel, umbilical hernia, and a large tongue (macroglossia).

thyroid storm

A rare but life-threatening complication of Hyperthyroidism

Grave’s Disease

•An autoimmune disease that affects the thyroid

symptoms of graves disease

•Exophthalmos (Graves’ ophthalmopathy) – swelling of the eyes

•Pretibial myxedema – edema that causes thickening of the skin (orange peel texture) in the lower legs

Hyperparathyroidism

•is characterized by weakness, weight loss, fatigue, muscular atrophy, bone pain, GI problems, pancreatitis, kidney stones, and the presence of adenomas.

Hypoparathyroidism

•causes numbness in the extremities and mouth, muscle cramps in the hands and feet, irritability, and depression.

Tetany

•is a medical sign consisting of the involuntary contraction of muscles. Tests like Chvostek’s sign and Trousseau’s sign are used to diagnose tetany. (Not the same thing as tetanus, but comes from the same root word.)

Addison’s Disease aka primary adrenal insufficiency

A rare, often autoimmune-related endocrine disorder caused by inadequate production of cortisol and aldosterone

bronze discoloration

Low cortisol can also result in hyperpigmentation

Adrenal Crisis AKA Addisonian crisis or acute adrenal insufficiency

life-threatening complication of adrenal insufficiency

Cushing’s Syndrome

•Iatrogenic condition caused by prolonged exposure to glucocorticoids like cortisol (Prednisone).

Waterhouse-Friderichsen Syndrome

A failure of the adrenal glands to secrete appropriate corticosteroid levels due to bleeding in the adrenal cortex