Endocrine System: Endocrine Glands, Hormones, and Hormonal Diseases

Norepinephrine

A hormone secreted by the adrenal medulla during times of stress that last 10 times longer than its neurotransmitter form

Luteinizing Hormone (LH)

A hormone that the anterior pituitary gland secretes that formation of the corpus luteum in females and testosterone secretion in males

Negative Feedback

A mechanism that returns the level of a chemical or other substance or condition in the internal environment to its set point level

Pineal Disorder

A rare, aggressive type of cancer that begins in the cells of the brain's pineal gland

Pineal Gland

A small gland in the brain that secretes the hormone melatonin, which controls certain biological rhythms

Water-Soluble

Ability to bind to a receptor protein on the plasma membrane of the cell

Lipid-Soluble

Ability to diffuse through the plasma membrane of lipids or fat tissue to enter the target cell and bind to a receptor protein

Aldosterone

Adrenal cortical hormone that regulates plasma sodium and potassium ion concentrations and fluid volume

Hormones of the Adrenal Cortex

Aldosterone, Cortisol, and Adrenal Androgens

Type 1 Diabetes Mellitus

An autoimmune disorder in which beta cells are destroyed, so insulin production decreases or stops

Goiter

An enlarged thyroid that appears as a bulge in the neck

Graves Disease

An immune system disorder that results in the overproduction of thyroid hormones (hyperthyroidism)

Gigantism

An overgrowth of long bones that occurs in childhood due to GH oversecretion during childhood

Hormones of the Posterior Pituitary

Antidiuretic Hormone (ADH), and Oxytocin (OT)

Type 2 Diabetes Mellitus

Autoimmune disorder when small or inadequate amounts of insulin produced or the body rejects insulin, affecting the way the body processes glucose

Composition of Secreting Glands

Composed of epithelial tissue

Function of the Hypothalamus

Controls the activity of the pituitary gland

Hypothyroidism

Decrease in thyroxine, which slows metabolic processes

Hypoparathyroidism

Deficiency of PTH, due to surgival removal or injury to glands, which results in a decrease in blood calcium

Pituitary Gland

Endocrine gland attached to the base of the brain consisting of anterior and posterior lobes

Thyroid Gland

Endocrine gland consisting of two connected lobes located in the anterior neck, just below the larynx and in front and to the side of the trachea whose hormones help control how many calories are consumed and play a role in bone growth and maintenance of blood calcium and phosphate levels

Adrenal Gland

Endocrine gland on the superior portion of each kidney that include adrenal hormones playing roles in maintaining blood sodium levels and responding to stress and certain sex hormones

Pancreatic Islets (Islets of Langerhans)

Endocrine portion of the pancreas that include 2 cell types: alpha cells that secrete glucagon and beta cells that secrete insulin

Hormones of the Adrenal Medulla

Epinephrine and Norepinephrine

Hormones of the Ovaries

Estrogen and Progesterone

Hyperparathyroidism

Excess of PTH, perhaps due to parathyroid tumor, which results in an increase in blood calcium

Progesterone

Female hormone secreted by the corpus luteum of the ovary and by the placenta

Anterior Pituitary

Front lobe of the pituitary gland that secretes growth hormone (GH), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), prolactin (PRL), luteinizing hormone (LH), and follicle-stimulating hormone (FSH)

Thymus

Gland in the mediastinum, superior to the heart, that secretes hormones involved in development of the immune system

Endocrine Gland

Gland that secretes hormones into the bloodstream; hormone-secreting gland

Exocrine Gland

Gland that secretes its products into a duct or onto an outside body surface

Pancreas

Glandular organ in the abdominal cavity that secretes the hormones insulin and glucagon into the bloodstream, and a variety of digestive enzymes into the small intestine

Hormones of the Pancreatic Islets

Glucagon and Insulin

Cortisol

Glucocorticoid hormone secreted by the adrenal cortex

Prostaglandins

Group of compounds that have powerful, hormone-like effects; lipids produced from the fatty acid in cell membranes

Estrogen

Group of hormones that stimulates the development of female secondary sex characteristics and produces an environment suitable for fertilization, implantation, and growth of an embryo

Thymosin

Group of peptides the thymus secretes that increases the production of certain types of white blood cells

Hormones of the Anterior Pituitary

Growth hormone (GH), Prolactin (PRL), Thyroid-stimulating hormone (TSH), Adrenocorticotropic hormone (ACTH), Follicle-stimulating hormone (FSH), and Luteinizing hormone (LH)

Function of the Thyroid Gland

Helps control caloric intake and regulates blood calcium level and bone growth

Antidiuretic Hormone (ADH)

Hormone of the posterior pituitary gland that enhances water conservation in the kidneys; known as vasopresin due to its ability to cause vasoconstriction

Growth Hormone (GH)

Hormone secreted by the anterior pituitary that promotes growth of the organism; somatotropin

Follicle-Stimulating Hormone (FSH)

Hormone secreted by the anterior pituitary that stimulates development of an ovarian follicle in a female, or sperm cell production in a male

Prolactin (PRL)

Hormone secreted by the anterior pituitary that stimulates milk production in the mammary glands

Glucagon

Hormone secreted by the pancreatic islets that raises blood sugar concentration by stimulating the liver to break down glycogen and convert certain noncarbohydrates, such as amino acids, into glucose

Parathyroid Hormone (PTH)

Hormone secreted by the parathyroid glands that helps regulate the levels of blood calcium and phosphate ions

Calcitonin (CT)

Hormone secreted by the thyroid gland that helps regulate the blood calcium and phosphate concentrations

Thyroid-Stimulating Hormone (Thyrotropin or TSH)

Hormone secreted from the anterior pituitary that stimulates secretion of thyroid hormones from the thyroid gland

Gonadotropin

Hormone that stimulates the activities in the goads

Adrenocorticotropic Hormone (ACTH)

Hormone that the anterior pituitary secretes that stimulates activity in the adrenal cortex

Melatonin

Hormone that the pineal gland secretes

Epinephrine

Hormone the adrenal medulla secretes during times of stress that last 10 times longer than its neurotransmitter form

Insulin

Hormone the pancreatic islets secrete that lowers the blood glucose concentration by stimulating cells to take up glucose

Adrenal Androgens

Hormones produced by the adrenal glands that program various aspects of puberty, such as growth of body hair, skin changes, and sexual desire

Crushing Syndrome

Hypersecretion of adrenal cortical hormones

Diabetes Mellitus

Hypofunction of the islets of Langerhans, which produce insulin, due to lack of insulin or the inability of cells to recognize insulin

Addison Disease

Hyposecretion of glucocorticoids and mineralocorticords

Hyperthyroidism

Increase in thyroxine; symptoms include hypertension, tachycardia, goiter, and exophthalmos

Adrenal Medulla

Inner part of the adrenal gland

Diabetes

Insipidus; a decrease of ADH, causing an excessive loss of water

Steroid Hormones

Lipid-soluble hormones derived from cholesterol that binds with DNA and activates specific genes, which direct the synthesis of specific proteins

Function of the Pituitary Gland

Master gland that produces hormones

Hormone of the Pineal Gland

Melatonin

Dwarfism

Occurs in children; body has normal proportions and intelligence is normal due to GH deficiency during childhood

Cretinism

Occurs in children; slows mental and physical development

Parathyroid Gland

One of the four small endocrine glands embedded in the posterior part of the thyroid gland that secretes a hormone that helps control blood calcium and phosphate levels

Thyroxine (T4 or Tetraiodothyronine)

One of the thyroid hormones that plays a role in controlling the basal metabolic rate

Triiodothyronine (T3)

One of the thyroid hormones that plays a role in controlling the basal metabolic rate

Adrenal Cortex

Outer part of the adrenal gland

Reproductive Glands

Ovaries and testes

Acromegaly

Overdevelopment of bones of the face in adults due to GH oversecretion in adulthood

Hormone of the Parathyroid Gland

Parathyroid Hormone (PTH)

Hypothalamus

Part of the brain below the thalamus and forming the floor of the third ventricle

Major Endocrine Glands

Pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, pineal gland, reproductive glands (ovaries and testes), kidneys, and thymus gland

Oxytocin (OT)

Posterior pituitary hormone that contracts smooth muscle in the uterus and mammary gland myoepithelial cells

Ovary

Primary female reproductive organ; egg cell-producing organ

Function of the Adrenal Cortex

Produce over 30 steroids with some being vital to survive, including aldosterone, cortisol, and sex hormones

Function of the Adrenal Gland

Produces hormones that help the body control blood sugar, burn protein and fat, react to stressors like a major illness or injury, and regulate blood pressure.

Posterior Pituitary

Rear lobe of the pituitary gland that secretes oxytocin and antidiuretic hormone (vasopressin)

Function of Endocrine Glands and Their Hormones

Regulate a number of metabolic processes within cells and the whole body

Function of the Parathyroid Gland

Regulates calcium in blood and phosphate levels

Functions of the Pancreas

Secretes hormones as an endocrine gland and digestive juice into the digestive tract as an exocrine gland, controls level of blood glucose

Function of the Pineal Gland

Secretes melatonin, which is involved in the regulation of circadian rhythms of the body

Function of the Thymus

Secretes thymosins, affecting production and differentiation of T lymphocytes

Negative Feedback and Gland

Sensitive to the concentration of the substance it regulates in order to maintain fairly constant hormone levels, fluctuating within a normal average range

Myxedema

Severe form of hypothyroidism that slows body processes to critical condition; occurs in adults

2 Types of Hormones

Steroids (or steroid-like substances) and nonsteroids (amines, peptides, proteins, or glycoproteins)

Function of the Anterior Pituitary Gland

Stimulate or inhibit the release of specific hormones

Function of the Posterior Pituitary Gland

Stores hormones made by the hypothalamus and releases these hormones into the blood in response to nerve impulses from the hypothalamus

Basal Metabolic Rate

The caloric intake necessary to maintain life

Endocrine System

The organ system that includes the glands that secrete hormones into the blood

Hormone of the Thymus

Thymosin

Hormones of the Thyroid Gland

Thyroxine (T4 or Tetraiodothyronine), Triiodothyronine (T3), and Calcitonin (CT)

Nonsteroid Hormones

Water-soluble hormones that combine with receptors in target cell membranes, activating a chain of molecules and causing a series of reactions that lead to cellular changes associated with the hormones' action

Function of the Endocrine System

Works with the nervous system to maintain homeostasis, communicates with cells using hormones

Adrenal Disorders

• Hyperfunction: Crushing's Syndrome, including hypertension, muscular weakness, and "moon" face • Hypofunction: Addison's Disease

Pituitary Disorders

• Hyperfunction: Gigantism & Acromegaly • Hypofunction: Dwarfism & Diabetes

Thyroid Disorders

• Hyperfunction: Hyperthyroidism • Hypofunction: Hypothyroidism, Myxedema, & Cretinism

Parathyroid Disorders

• Hyperfunction: Kidney Stones, Bone Deformity, and Hypoparathyroidism • Hypofunction: Hypoparathyroidism

Pancreas Disorders

• Hyperfunction: unknown • Hypofunction: Diabetes Mellitus

Negative Feedback and Hormone Level Regulation

•Release of hormones from the hypothalamus controls secretions of the anterior pituitary, and anterior pituitary hormones affect the activity of other endocrine glands •The nervous system influences certain endocrine glands directly •Other glands respond directly to changes in the internal fluid composition