Endocrine system

OpenStax College / CC BY

Understanding the endocrine system
• Hypothalamus helps control endocrine glands.
• Adrenal cortex secretes mineralocorticoids, glucocorticoids, adrenal androgens, and estrogen.
• Adrenal medulla produces epinephrine and norepinephrine.
• Pancreas produces glucagon and insulin.
• Pituitary gland secretes oxytocin and antidiuretic hormone.
• Thyroid gland secretes thyroxine and triiodothyronine.
• Parathyroid glands secrete parathyroid hormone.

Endocrine disorders are caused by:
• hypersecretion or hyposecretion of hormones
• hyporesponsiveness of receptors of hormones
• inflammation of gland
• tumor of gland.

How endocrine disorders develop
• Addison’s disease — autoimmune disease (primary) that causes massive destruction of both adrenal glands.
• Cushing’s syndrome — typically results from excess corticotropin, which leads to hyperplasia of the adrenal cortex.
• Diabetes insipidus — caused by deficiency of antidiuretic hormone (ADH).
• Diabetes mellitus — disease occurs in two primary forms:
type 1 — beta cells in pancreas are destroyed or suppressed; insulin isn’t secreted.
type 2 — may be insulin resistance, overproduction of glucose, or abnormal insulin secretion.
• Goiter — enlargement of the thyroid gland. This condition occurs in two forms:
–nontoxic goiter — thyroid gland is enlarged because it’s unable to secrete enough thyroid hormone to meet metabolic needs.
–toxic goiter — occurs after long-standing nontoxic goiter.
• Hyperthyroidism — autoimmune disorder that overproduces thyroid hormone.
• Hypothyroidism — a thyroid deficiency that causes metabolic processes to slow down.