Endocrine.

Endocrine glands are ductless glands that release hormones directly into the bloodstream, where they travel to target organs and tissues. The liver filters blood but is not the target for endocrine secretion. The gut has local hormones (like gastrin) but endocrine glands do not secrete into the gut. The heart produces ANP, but releases it into the bloodstream.

The pineal gland is a small gland in the brain that produces melatonin, a hormone regulating the sleep-wake cycle. The adrenal gland has an outer cortex (producing cortisol, aldosterone, and sex hormones) and an inner medulla (producing epinephrine and norepinephrine). The anterior pituitary produces TSH, ACTH, FSH, LH, prolactin, growth hormone, and melanocyte-stimulating hormone. The posterior pituitary stores and releases oxytocin and antidiuretic hormone (produced by the hypothalamus). The parathyroid gland produces parathyroid hormone.

The thyroid gland secretes thyroid hormone and calcitonin. Calcitonin lowers calcium levels. The anterior pituitary produces TSH, ACTH, FSH, LH, prolactin, growth hormone, and melanocyte-stimulating hormone. The posterior pituitary stores and releases oxytocin and ADH (produced by the hypothalamus). The pancreas secretes insulin and glucagon. The parathyroid gland secretes parathyroid hormone, which increases calcium levels.

The adrenal medulla secretes epinephrine and norepinephrine. The adrenal cortex secretes cortisol and aldosterone. The thyroid gland secretes calcitonin. The pineal gland secretes melatonin.

Glucagon is produced by alpha cells in the islets of Langerhans and raises blood glucose. The pancreas has both endocrine functions (glucagon from alpha cells, insulin from beta cells, somatostatin from delta cells) and exocrine functions (digestive enzymes like amylase, lipase, and proteases). Aldosterone is produced by the adrenal cortex. Albumin is produced by the liver (it is a plasma protein). Growth hormone is produced by the anterior pituitary.

The ovary produces estrogen. Small amounts are also produced by the adrenal glands. The pituitary gland produces FSH and LH, which stimulate estrogen production, but does not secrete estrogen itself. The uterus responds to estrogen but does not produce it. Breast tissue develops under estrogen influence but does not produce it.

Dips/o means thirst. Polydipsia means excessive thirst. Phagia means eating, so polyphagia is excessive eating. Uria means urine, so polyuria is excessive urination. Hidrosis means sweating, so hyperhidrosis is excessive sweating.

Excess growth hormone in adulthood causes acromegaly, characterized by large hands, feet, and coarsened facial features. In childhood, excess growth hormone causes gigantism. Addison's disease involves deficiency of both cortisol and aldosterone. Cushing's disease is caused by excess cortisol. Diabetes mellitus results from deficient insulin.

Low antidiuretic hormone causes diabetes insipidus. In this condition, the patient produces large volumes of dilute urine because of an inability to concentrate urine. It is distinct from diabetes mellitus. Excess growth hormone in childhood causes gigantism. Deficiency of thyroid hormone causes myxedema in adults and cretinism in newborns.

Kal/i refers to potassium (chemical symbol K). Hypokalemia means low blood potassium levels. The suffix -emia means blood. Glyc/o means sugar (hypoglycemia = low blood sugar). Calc/o refers to calcium (hypocalcemia = low blood calcium). Natr/o refers to sodium, symbol Na (hyponatremia = low sodium).