ch 12 The Endocrine System

Endocrine System

A group of glands that produce hormones and work with the nervous system to control and coordinate all other body systems.

Hormones

Chemical messengers with regulatory effects on cells or organs. They are released directly into tissue fluids, not through ducts.

Hypothalamus

A part of the brain that produces releasing hormones to control the release of anterior pituitary hormones.

Pituitary Gland

Known as the "master gland," it releases hormones that affect the working of other endocrine glands.

Thyroid Gland

Located in the neck, it produces hormones that regulate metabolism and growth.

Parathyroid Glands

Small glands located near the thyroid gland that regulate calcium levels in the blood.

Adrenal Glands

Located on top of the kidneys, they produce hormones that help regulate stress response and metabolism.

Pancreatic Islets

Clusters of cells in the pancreas that produce hormones involved in regulating blood sugar levels.

Testes

Male reproductive organs that produce testosterone and play a role in sexual development.

Ovaries

Female reproductive organs that produce estrogen and progesterone and play a role in sexual development and reproductive processes.

Negative Feedback

A regulatory mechanism in which an increase in a hormone's concentration leads to a decrease in its production.

Positive Feedback

A regulatory mechanism in which an increase in a hormone's concentration leads to an increase in its production.

Gigantism

A condition characterized by excessive growth in children due to overproduction of growth hormone.

Acromegaly

A condition characterized by excessive growth in adults, resulting in enlarged facial features, hands, and feet.

Goiter

An enlargement of the thyroid gland, often caused by iodine deficiency.

Hypothyroidism

A condition characterized by an underactive thyroid gland, leading to symptoms such as fatigue, weight gain, and depression.

Hyperthyroidism

A condition characterized by an overactive thyroid gland, leading to symptoms such as weight loss, rapid heartbeat, and anxiety.

Parathyroid Glands

Four glands in the posterior capsule of the thyroid that secrete parathyroid hormone (PTH) to regulate calcium metabolism.

PTH

Parathyroid hormone that works with calcitonin to regulate calcium metabolism.

Hyposecretion

A condition of the parathyroid glands where there is a deficiency of calcium, leading to tetany, which is marked by intermittent muscular spasms.

Hypersecretion

Increased secretion of PTH, causing calcium to be pulled from storage into the bloodstream. This can lead to fragile bones that fracture easily and the formation of kidney stones.

Adrenal Glands

Two small glands on top of the kidneys that have two parts - the medulla (inside) and the cortex (outside).

Adrenal Medulla

The inner region of the adrenal gland.

Adrenal Cortex

The outer region of the adrenal gland.

Glucocorticoids

Hormones, such as cortisol, that increase blood glucose in response to stress.

Mineralocorticoids

Hormones, such as aldosterone, that regulate salt/water retention and potassium excretion.

Sex Hormones

Hormones produced by the adrenal medulla.

Addison Disease

A disorder of the adrenal cortex characterized by hyposecretion, resulting in symptoms such as muscle atrophy, weakness, and salt/water imbalance.

Cushing Syndrome

A disorder of the adrenal cortex characterized by hypersecretion of cortisol, leading to symptoms such as obesity, muscle weakness, and elevated blood glucose.

Pancreas

An organ with two parts - acini (secrete digestive enzymes) and islets (secrete hormones).

Insulin

A hormone produced by the islets of the pancreas that lowers blood sugar levels and stimulates the manufacture of amino acids into protein.

Glucagon

A hormone produced by the islets of the pancreas that increases blood sugar levels.

Diabetes Mellitus

The most common endocrine disorder, with different types including type 1 diabetes (destruction of insulin-producing cells), type 2 diabetes (insulin resistance), metabolic syndrome (signs of increased risk for T2DM or cardiovascular disease), and gestational diabetes (during pregnancy).

Ovaries

Female sex glands that produce hormones to develop sexual characteristics and maintain reproductive organs.

Testes

Male sex glands that produce hormones, such as androgens (including testosterone), to develop sexual characteristics and maintain reproductive organs.

Pineal Gland

A cone-shaped structure posterior to the midbrain that produces melatonin, which influences sleep-wake cycles and delays the onset of puberty.

Prostaglandins

A group of hormones made by most body tissues that have various functions, including constricting or dilating structures and promoting inflammation.

Hormones and Treatment

Various hormones, such as growth hormone, insulin, adrenal steroids, epinephrine, thyroid hormones, oxytocin, and sex hormones, can be extracted from animal tissue, manufactured in the lab, or genetically engineered for medical treatment.

Aging and the Endocrine System

The decline in hormone secretion with age can contribute to clinical conditions such as type 2 diabetes mellitus and osteoporosis.

Word Anatomy

A list of word parts and their meanings related to the endocrine system, such as acr/o (end, extremity), andr/o (male), cortic/o (cortex), glyc/o (glucose, sugar), insul/o (pancreatic islet), lact/o (milk), -megaly (enlargement), nephr/o (kidney), oxy- (sharp, acute), ren/o (kidney), -sterone (steroid hormone), toc/o (labor), trop/o (acting on), and ur/o (urine).