II. Definitions

  1. Cytokine
    1. See Cytokine
    2. Short-range, cell-released molecules that influence the same cell (Autocrine) or nearby cells (Paracrine)
  2. Autocrine Communication
    1. Cytokines that influence the same cell that released the molecule
  3. Paracrine Communication
    1. Cytokines that diffuse to influence nearby cells
  4. Endocrine Glands
    1. Glands that secrete hormonal agents that act systemically
    2. Contrast with exocrine glands (e.g. Salivary Glands) that secrete molecules locally into ducts
  5. Hormones
    1. Molecules secreted by endocrine organs, and carried by the vascular system to influence cells at distant sites
    2. Hormones may be Proteins (e.g. TSH), Amino Acid derivatives (e.g. Thyroxine) or steroid rings (e.g. Progesterone)

III. Physiology: Hormonal Activity

  1. Polypeptides (e.g. Epinephrine)
    1. Bind cell surface receptors
    2. Receptor binding triggers G Protein (intermediate molecule) release
    3. G Proteins stimulate secondary messengers release (e.g. cAMP, cGMP)
  2. Steroid Hormones (e.g. Progesterone)
    1. Bind cytoplasmic receptors to form molecule complex
    2. Complex enters nucleus to influence Protein transcription
  3. Amino Acid Derivatives (e.g. Thyroxine)
    1. Thyroxine enters cells and acts directly within nucleus to influence Protein transcription

IV. Preparations: Hypothalamus and Pituitary Hormones

  1. Hypothalamus
    1. Corticotropin Releasing Hormone (CRH, CRF)
      1. Stimulates anterior pituitary release of Adrenocorticotropic Hormone (ACTH)
    2. Gonadotropin Releasing Hormone (GnRH, LHRH)
      1. Stimulates anterior pituitary release of Follicle Stimulating Hormone (FSH)
      2. Stimulates anterior pituitary release of Luteinizing Hormone (LH)
    3. Growth Hormone Releasing Hormone (GHRH)
      1. Stimulates anterior pituitary release of Growth Hormone
    4. Thyrotropin Releasing Hormone (TRH, TRF)
      1. Stimulates anterior pituitary release of Thyroid Stimulating Hormone (TSH)
      2. Stimulates anterior pituitary release of Prolactin
    5. Somatostatin
      1. Inhibits anterior pituitary release of Growth Hormone
      2. Inhibits anterior pituitary release of Thyroid Stimulating Hormone (TSH)
    6. Neurotransmitters
      1. Dopamine released from Hypothalamus inhibits anterior pituitary release of Prolactin
  2. Posterior Pituitary Gland (Hormones produced in the Hypothalamus, released from pituitary)
    1. Oxytocin
      1. Stimulates uterine contractions
      2. Stimulates milk let-down in Lactation
    2. Antidiuretic Hormone (ADH, Vasopressin)
      1. Increases renal water reaborption
  3. Anterior Pituitary Gland
    1. Prolactin
      1. Protein synthesized and secreted by Lactotrophs (acidophil cells) in the anterior pituitary
      2. Prolactin stimulates milk secretion into the Breast alveoli in pregnancy and Lactation
      3. Oxytocin stimulates myoepithelial cells to contract, expressing Breast Milk from the nipple
      4. Stimulated by Estrogen, vasoactive intestinal polypeptide (VIP), Thyroid Releasing Hormone (TRH)
      5. Inhibition by hypothalamic Dopamine (Prolactin Inhibiting Factor or PIF)
    2. Human Growth Hormone
      1. Polypeptide produced in the acidophil cells of the anterior pituitary
      2. Triggered by Hypoglycemia (or low Amino Acids) via hypothalamic release of GHRH
      3. Promotes bone and cartilage growth, Protein synthesis, glycogen storage, Fatty Acid increase
    3. Adrenocorticotropic Hormone (ACTH)
      1. Polypeptide synthesized and secreted by Basophil cells in the anterior pituitary
      2. Stimulation (releasing factors) include Corticotropin Releasing Hormone (CRH) and stress
      3. Inhibition by negative feedback loops (Cortisol inhibits CRH and ACTH release)
      4. ACTH stimulates the Adrenal Cortex to release Cortisol (and to a lesser extent Aldosterone and androgens)
    4. Thyroid Stimulating Hormone (TSH)
      1. See Thyroid Physiology
      2. Thyroid Stimulating Hormone (TSH) is a Glycoprotein synthesized in the Basophil cells of the anterior pituitary
      3. Stimulated by Thyroid Releasing Hormone (TRH)
      4. Inhibited by negative feedback from Thyroid Hormones (T4, T3)
      5. Thyroid Stimulating Hormone (TSH) promotes all aspects of Thyroid Hormone production
        1. Increases iodide uptake and incorporation of Iodine into Thyroglobulin
        2. Increases lysis into active Thyroid Hormones T4 and T3
    5. Follicle Stimulating Hormone (FSH)
      1. FSH is a glyoprotein secreted by Basophil cells in the anterior Pituitary Gland
      2. Stimulation (releasing factors) is by Hypothalamic Gonadotrophic Releasing Hormone (GnRH)
      3. Inhibited via negative feedback loop by Testosterone, Estrogens, Progesterone and inhibin
      4. FSH stimulates ovarian follicle growth (which secretes Estradiol) in women
      5. FSH stimulates spermatogenesis and sperm maturation within Sertoli Cells in men
    6. Luteinizing Hormone (LH)
      1. LH is a Glycoprotein secreted by Basophil cells in the anterior Pituitary Gland
      2. Stimulation is by Hypothalamic Gonadotrophic Releasing Hormone (GnRH)
      3. Inhibited via negative feedback loop by Testosterone, Estrogens, Progesterone and inhibin
      4. LH stimulates ovarian follicles to ovulate and mature into a corpus luteum (produces Estrogen, Progesterone)
      5. LH stimulates Leydig Cells within Testes to produce Testosterone

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Related Studies

Ontology: Endocrine system (C0014136)

Definition (MSHCZE) Systém žláz, které uvolňují výměšky (hormony) přímo do oběhového systému. Kromě ENDOKRINNÍCH ŽLÁZ sem patří i CHROMAFINNÍ SYSTÉM a NEUROSEKREČNÍ SYSTÉMY.
Definition (NCI_NCI-GLOSS) A system of glands and cells that make hormones that are released directly into the blood and travel to tissues and organs all over the body. The endocrine system controls growth, sexual development, sleep, hunger, and the way the body uses food.
Definition (NCI) Collective designation for those tissues capable of secreting hormones.
Definition (MSH) The system of glands that release their secretions (hormones) directly into the circulatory system. In addition to the ENDOCRINE GLANDS, included are the CHROMAFFIN SYSTEM and the NEUROSECRETORY SYSTEMS.
Definition (CSP) ductless glands that secrete substances which are released directly into the circulation and which influence metabolism and other body functions.
Concepts Body System (T022)
MSH D004703
SnomedCT 113331007
LNC LP31396-2, LP7203-5, MTHU001408
English Endocrine System, Endocrine Systems, System, Endocrine, Systems, Endocrine, Endocrine structure (body structure), Endocrine structure, Structure of endocrine system, Structure of endocrine system (body structure), Systema endocrinum, Endocrine, endocrine systems, endocrine system, endocrine glands system, endocrine gland/system, Endocrine system structure, Endocrine system, Body System, Endocrine/Metabolic, Endocrine/Metabolic Body System, Hormonal System, Organ System, Endocrine/Metabolic, Endocrine/Metabolic Organ System, Metabolic/Endocrine Body System
Swedish Endokrina systemet
Czech endokrinní systém
Finnish Umpieritysjärjestelmä
Latvian Endokrīnā sistēma
Polish Układ wewnątrzwydzielniczy, Układ endokrynny, Układ wydzielania wewnętrznego
Norwegian Endokrine system, Hormonsystemet, Hormonene
Spanish estructura del sistema endocrino (estructura corporal), estructura del sistema endocrino, sistema endocrino, Sistema Endocrino
French Système endocrine, Système endocrinien
German Endokrines System
Italian Sistema endocrino
Dutch Endocrien systeem, Systeem, endocrien
Portuguese Sistema Endócrino

Ontology: Hormones (C0019932)

Definition (MEDLINEPLUS)

Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work slowly, over time, and affect many different processes, including

  • Growth and development
  • Metabolism - how your body gets energy from the foods you eat
  • Sexual function
  • Reproduction
  • Mood

Endocrine glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, thymus, thyroid, adrenal glands, and pancreas. In addition, men produce hormones in their testes and women produce them in their ovaries.

Hormones are powerful. It takes only a tiny amount to cause big changes in cells or even your whole body. That is why too much or too little of a certain hormone can be serious. Laboratory tests can measure the hormone levels in your blood, urine, or saliva. Your health care provider may perform these tests if you have symptoms of a hormone disorder. Home pregnancy tests are similar - they test for pregnancy hormones in your urine.

Definition (NCI) Any synthetic or animal-derived agent that is chemically identical or similar to an endogenous hormone with therapeutic application.
Definition (NCI_NCI-GLOSS) One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.
Definition (MSH) Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects.
Definition (CSP) chemical substances having a specific regulatory effect on the activity of a certain organ or organs, especially substances secreted by various endocrine glands and transported in the bloodstream to the target organs.
Concepts Hormone (T125)
MSH D006728
SnomedCT 87568004
LNC LP28776-0, LA4003-5
English Hormone, Hormones, hormones, hormones (medication), Synthetic Hormone, Hormones [Chemical/Ingredient], hormone, Hormone (substance), Hormone, NOS, Endocrine Gland Secretion, Therapeutic Hormone
French Hormones, Hormone
Swedish Hormoner
Czech hormony
Finnish Hormonit
Japanese ホルモン-合成, 合成ホルモン, ホルモン
Italian Ormone, Ormoni
Croatian HORMONI
Polish Hormony
Norwegian Hormoner, Hormon
Portuguese Hormonas, Hormônios
Spanish hormona (sustancia), hormona, Hormonas
German Hormone

Ontology: Autocrine Communication (C0525010)

Definition (GO) Signaling between cells of the same type. The signal produced by the signaling cell binds to a receptor on, and affects a cell of the same type. [GOC:bf, ISBN:3527303782]
Definition (MSH) Mode of communication wherein a bound hormone affects the function of the cell type that produced the hormone.
Concepts Cell Function (T043)
MSH D019898
English Autocrine Communication, Autocrine Communications, Autocrine Signaling, Autocrine Signalings, Communication, Autocrine, Communications, Autocrine, Signaling, Autocrine, Signalings, Autocrine, autocrine signaling, autocrine signalling
Swedish Autokrin kommunikation
Czech autokrinní regulace, autokrinní signalizace
Finnish Autokriininen viestintä
French Signalisation autocrine, Communication autocrine
Japanese オートクリンコミュニケーション, オートクリンシグナリング, オートクリンシグナル
Italian Trasmissione autocrina
Polish Komunikacja autokrynna, Oddziaływanie autokrynne, Regulacja autokrynowa, Sygnalizacja autokrynna
German Autokrine Kommunikation, Autokrine Signalübertragung
Dutch Autocriene communicatie, Communicatie, autocriene
Portuguese Comunicação Autócrina, Sinalização Autócrina
Spanish Comunicación Autocrina, Señalización Autocrina

Ontology: Paracrine Communication (C0525011)

Definition (GO) The transfer of information from one cell to another, where the signal travels from the signal-producing cell to the receiving cell by passive diffusion or bulk flow in intercellular fluid. The signaling cell and the receiving cell are usually in the vicinity of each other. [GOC:mtg_signaling_feb11, ISBN:3527303782]
Definition (MSH) Cellular signaling in which a factor secreted by a cell affects other cells in the local environment. This term is often used to denote the action of INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS on surrounding cells.
Concepts Cell Function (T043)
MSH D019899
English Communication, Paracrine, Communications, Paracrine, Paracrine Communication, Paracrine Communications, Paracrine Signaling, Paracrine Signalings, Signaling, Paracrine, Signalings, Paracrine, paracrine signals, paracrine communication, paracrine signal, paracrine signalling, paracrine signaling
Swedish Parakrin kommunikation
Czech parakrinní signalizace, parakrinní regulace
Finnish Parakriininen viestintä
French Signalisation paracrine, Communication paracrine
Japanese パラクリンコミュニケーション, パラ分泌型シグナル, 傍分泌型シグナル, パラクリンシグナリング, パラクリンシグナル, パラ分泌型シグナリング, 傍分泌型シグナリング
Italian Segnalazione paracrina, Trasmissione paracrina
Polish Komunikacja parakrynna, Oddziaływanie parakrynne, Regulacja parakrynowa
German Parakrine Kommunikation, Parakrine Signalisierung
Dutch Communicatie, paracriene, Paracriene communicatie
Portuguese Comunicação Parácrina, Sinalização Parácrina
Spanish Comunicación Paracrina, Señalización Paracrina