Vocabulary The Endocrine System
Long-distance chemical signals that travel in blood or lymph throughout the body.
Name the endocrine system organs
Tiny, pine cone-shaped, hangs from the roof of the third ventricle in the diencephalon in the brain, endocrine function is still a mystery, but releases melatonin (sleep cycle).
Above the pituitary gland. Produces oxytocin and ADH which exits out the posterior pituitary (just stores the hormones, doesn't produce any itself, part of NS). Also secretes releasing and inhibiting hormones
Just under the hypothalamus, produces hormones such as TSH, FSH, LH, ACTH, GH, and PRL.
Located in the anterior neck on the trachea just inferior to the larynx. Largest pure endocrine gland in the body, produces Thyroid Hormone (affects virtually every cell in the body) and Calcitonin (bone-sparing effect).
On posterior side of thyroid gland, usually 4 of them. Secretes Parathyroid hormone (single most important hormone controlling the calcium balance of the blood).
is an organ in the upper chest cavity that processes lymphocytes, a type of white blood cell that fights infections in the body. Secretes Thymulin, Thymopoietins and Thymosins
A Pyramid-shaped organ on top of the kidneys, inner is adrenal medulla which releases Epinephrine (EPI) and Norepinephrine (NE), outer is adrenal cortex and synthesizes corticosteroids. All adrenal hormones help us cope with stressful situations.
Partially behind the stomach in the abdomen, produces glucagon and insulin.
The pair of male reproductive glands enclosed in the scrotum that produce the male sex hormone testosterone and the spermatozoa.
The ovaries are magnificent glands which are part of the female reproductive system. The ovaries are about the size and shape of an almond and sit just above the fallopian tubes -- one ovary on each side of the uterus. Every month during ovulation, either the right or left ovary produces a single mature egg for fertilization. Secretes Estrogen and Progesterone
Secreted by the pineal gland, plays an important role in the regulation of sleep cycles. Its production is influenced by the detection of light and dark by the retina of the eye. For example, the production of melatonin is inhibited when the retina detects light and is stimulated in the absence of light.
a hypothalamic hormone stored in the posterior pituitary, which has uterine-contracting and milk-releasing actions
Antidiuretic Hormone (ADH)
A relatively small (peptide) molecule that is released by the pituitary gland at the base of the brain after being made nearby (in the hypothalamus). ADH has an antidiuretic action that prevents the production of dilute urine
Thyroid Stimulating Hormone (TSH)
A hormone produced by the pituitary gland at the base of the brain in response to signals from the hypothalamus gland in the brain.
TSH promotes the growth of the thyroid gland in the neck and stimulates it to produce more thyroid hormones. When there is an excessive amount of thyroid hormones, the pituitary gland stops producing TSH, reducing thyroid hormone production. This mechanism maintains a relatively constant level of thyroid hormones circulating in the blood.
Follicle-Stimulating Hormone (FSH)
A hormone produced by the pituitary gland that controls estrogen production by the ovaries.
Luteinizing Hormone (LH)
A gonadotropin (a hormone that affects the function of the sex organs) that is released by the pituitary gland in response to luteinizing hormone-releasing hormone.
In females, LH controls the length and sequence of the female menstrual cycle, including ovulation, preparation of the uterus for implantation of a fertilized egg, and ovarian production of both estrogen and progesterone.
In males, LH stimulates the testes to produce androgen.
Adrenocorticotropic Hormone (ACTH)
Adrenocorticotropic hormone (ACTH), or corticotropin, is a hormone that is produced in and released from the pituitary gland. ACTH is normally released from the pituitary in response to stimulation with corticotropin-releasing hormone (CRH), a hormone produced in the hypothalamic region of the brain during various types of stress or pain. The principal action of ACTH is to stimulate the synthesis and release of steroid hormones from the adrenal glands, which lie on the surface of the kidneys. ACTH is the principal modulator of cortisol, the most important steroid hormone in man.
Growth Hormone (GH)
Secreted by the anterior lobe of the pituitary gland. It stimulates the growth of essentially all tissues of the body, including bone. GH is synthesized and secreted by anterior pituitary cells called somatotrophs, which release between one and two milligrams of the hormone each day. GH is vital for normal physical growth in children; its levels rise progressively during childhood and peak during the growth spurt that occurs in puberty.
Prolactin is a hormone produced in the pituitary gland, named because of its role in lactation. It also has other wide ranging functions in the body from acting on the reproductive system to influencing behaviour and regulating the immune system
Thyroid Hormone (T4 & T3)
The thyroid hormones, triiodothyronine (T3) and thyroxine (T4), are tyrosine-based hormones produced by the thyroid gland that are primarily responsible for regulation of metabolism. Iodine is necessary for the production of T3 and T4.
Polypeptide hormone secreted by C cells of the thyroid gland, and sometimes of the thymus and parathyroids, which lowers calcium and phosphate concentration in plasma and inhibits bone resorption
The most important endocrine regulator of calcium and phosphorus concentration in extracellular fluid. This hormone is secreted from cells of the parathyroid glands and finds its major target cells in bone and kidney.
(also known as adrenaline or adrenalin) is a hormone and a neurotransmitter. Epinephrine has many functions in the body, regulating heart rate, blood vessel and air passage diameters, and metabolic shifts; epinephrine release is a crucial component of the fight-or-flight response of the sympathetic nervous system.
A stress hormone, norepinephrine affects parts of the brain, such as the amygdala, where attention and responses are controlled. Along with epinephrine, norepinephrine also underlies the fight-or-flight response, directly increasing heart rate, triggering the release of glucose from energy stores, and increasing blood flow to skeletal muscle. It increases the brain's oxygen supply
Secreted by the adrenal gland mineralcorticoid steroid hormone that regulates the excretion of salt, potassium, and water.
Secreted by the adrenal gland glucocorticoid steroid hormone that affects fat, carbohydrate, and protein levels in the blood as well as regulating the immune response.
Secreted by the adrenal gland gonadocorticoid steroid that converts to testosterone of estrogen after release. Contributes to female libido, produces pubic and axillary hair, also a source of estrogen after menopause
A peptide hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar (glucose) levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream. High blood glucose levels stimulate the release of insulin. Insulin allows glucose to be taken up and used by insulin-dependent tissues. Thus, glucagon and insulin are part of a feedback system that keeps blood glucose levels at a stable level.
A peptide hormone, produced by beta cells of the pancreas, and is central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, skeletal muscles, and fat tissue to take up glucose from the blood. In the liver and skeletal muscles, glucose is stored as glycogen
A steroid hormone from the androgen group. In mammals, testosterone is primarily secreted in the testicles of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid.
Is responsible for the appearance of secondary sex characteristics for females at puberty and for the maturation and maintenance of the reproductive organs in their mature functional state.
Prepares uterus for pregnancy, and mammary gland for lactation. Progesterone functions with estrogen by promoting menstrual cycle changes in the endometrium.
Human Chorionic Gonadotropin (hCG)
A hormone produced during pregnancy that is made by the developing placenta after conception. Interacts with the LHCG receptor and promotes the maintenance of the corpus luteum during the beginning of pregnancy, causing it to secrete the hormone progesterone. Progesterone enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus. Due to its highly negative charge, hCG may repel the immune cells of the mother, protecting the fetus during the first trimester.
Atrial Natriuretic Peptide (ANP).
Produced by the heart. ANP decreases the amount of sodium in the extracellular fluid thereby reducing blood volume and blood pressure.
Secreted by the kidneys and is a glycoprotein hormone that signals bone marrow to increase production of red blood cells.
thyroid stimulating hormone
T4 & T3
The thyroid hormones, triiodothyronine (T3) and thyroxine (T4)
Atrial Natriuretic Peptide
Thymulin, Thymopoietins and Thymosins
Secreted by the Thymus
are short-distance chemical signals that exert their effect on the same cells that secret them. (ex. Prostaglandins released by smooth muscle causes that smooth muscle to contract.)
are short-distance chemical signals that exert their effect on cell types other than those secreting the paracrine chemicals.
Chemical class of hormones
Amino Acid Base
(all amino acid-based hormones except thyroid hormones) act on receptors in the plasma membrane. These receptors are usually coupled via regulatory molecules called G proteins to one or more intracellular second messengers which mediate the target cell response.
(steroid and thyroid hormones) act on receptors inside the cell, which directly activates genes and stimulating synthesis of specific proteins
one hormone cannot exert its full effects without another hormone being present (ex. Reproductive system hormones regulate the development of the reproductive system. However thyroid hormone is also necessary for normal timely development of reproductive structures. Lack of thyroid hormone delays reproductive development.
occurs when more than one hormone produces the same effect at the target cell and their combined effects are amplified. (ex. both glucagon (pancreas) and epinephrine causes the liver to release glucose into the blood. When they act together, the amount of glucose released is about 150% of what is released when each hormone acts alone
occurs when one hormones opposes the action of another hormone. (ex. insulin which lowers blood glucose levels, is antagonized by glucagon, which raises blood glucose levels.
are hormone-secreting cells sprinkled in the mucosa of the gastrointestinal tract (GI) These hormones help regulate a wide variety of digestive function.
Some endocrine glands secrete hormones directly according to the concentration of various ions and nutrients in the blood surrounding them
hormones are released directly due to stimulation of the endocrine gland by nerves. An important example of this is the release of adrenaline and noradrenaline (the catecholamines) from the adrenal gland in response to stimulation by the sympathetic nervous system.
many endocrine glands release their hormones in response to hormones produced by other endocrine systems
class of steroid hormones characterised by their influence on salt and water balances. The primary mineralocorticoid is aldosterone.
class of steroid hormones characterised by their influence on salt and water balances. The primary mineralocorticoid is aldosterone.
class of steroid hormones that bind to the glucocorticoid receptor. The name glucocorticoid (pertaining to glucose + cortex ) derives from its role in the regulation of the metabolism of glucose, its synthesis in the adrenal cortex, and its steroidal structure
androgens, steroid that converts to testosterone of estrogen after release. Contributes to female libido, produces pubic and axillary hair, also a source of estrogen after menopause.
is abnormally large growth due to an excess of growth hormone during childhood, before the bone growth plates have closed.
is a syndrome that results when the anterior pituitary gland produces excess growth hormone (GH) after epiphyseal plate closure at puberty. Nearly always as a result of a noncancerous (benign) tumor. The excess hormone causes swelling, skin thickening, tissue growth and bone enlargement, especially in your face, hands and feet.
is a condition characterized by growth and development disorders caused by insufficient secretion of pituitary somatotrope hormone (growth hormone or GH). The condition begins in childhood, but becomes more evident during puberty. Dwarfism is a condition in which growth is very slowed or delayed. Pituitary dwarfism is a consequence of decreased function of the pituitary gland occurred early in childhood before the ossification of bone cartilages.
is a condition characterized by excessive thirst and excretion of large amounts of severely diluted urine, with reduction of fluid intake having no effect on the concentration of the urine. Diabetes insipidus is either a problem with the production of antidiuretic hormone (central diabetes insipidus) or kidney's response to antidiuretic hormone.
(sometimes called "sugar diabetes") is a condition that occurs when the body can't use glucose (a type of sugar) normally. Glucose is the main source of energy for the body's cells. The levels of glucose in the blood are controlled by a hormone called insulin, which is made by the pancreas. Insulin helps glucose enter the cells.
In diabetes, the pancreas does not make enough insulin (type 1 diabetes) or the body can't respond normally to the insulin that is made (type 2 diabetes). This causes glucose levels in the blood to rise, leading to symptoms such as increased urination, extreme thirst, and unexplained weight loss.
a condition arising from a deficiency of thyroid hormone, present from birth, characterized by dwarfism and mental retardation
is a condition in which the thyroid gland does not make enough thyroid hormone. Symptoms: Early symptoms: Hard stools or constipation; Increased sensitivity to cold; Fatigue or feeling slowed down
is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often referred to as an "overactive thyroid." Symptoms: Difficulty concentrating; Fatigue.
describes the signs and symptoms associated with prolonged exposure to inappropriately high levels of the hormone cortisol. Symptoms include rapid weight gain, particularly of the trunk and face with sparing of the limbs (central obesity). A common sign is the growth of fat pads along the collar bone and on the back of the neck (buffalo hump) and a round face often referred to as a "moon face."
is the presence of abnormally high levels of prolactin in the blood. Hyperprolactinaemia may cause production and spontaneous flow of breast milk and disruptions in the normal menstrual period in women and hypogonadism, infertility and erectile dysfunction in men.
refers to abnormal enlargement of the thyroid gland. It is important to know that the presence of a goiter does not necessarily mean that the thyroid gland is malfunctioning. A goiter can occur in a gland that is producing too much hormone (hyperthyroidism), too little hormone (hypothyroidism), or the correct amount of hormone (euthyroidism). A goiter indicates there is a condition present which is causing the thyroid to grow abnormally. One of the most common causes of goiter formation worldwide is iodine deficiency.
is an autoimmune disease. It most commonly affects the thyroid, frequently causing it to enlarge to twice its size or more (goitre), become overactive, with related hyperthyroid symptoms such as increased heartbeat, muscle weakness, disturbed sleep, and irritability. It can also affect the eyes, causing bulging eyes (proptosis). It affects other systems of the body, including the skin, heart, circulation and nervous system.
a disorder marked by excessive secretion of the hormone aldosterone, which can cause weakness, cardiac irregularities, and abnormally high blood pressure.
is a rare, chronic endocrine disorder in which the adrenal glands do not produce sufficient steroid hormones (glucocorticoids and often mineralocorticoids). It is characterised by a number of relatively nonspecific symptoms, such as abdominal pain and weakness