endocrine

• What is the endocrine system?

  The endocrine system is a collection of glands that produce approximately 30 hormones.
• What functions do hormones regulate in the body?

  Hormones regulate metabolism, growth and development, tissue function, reproduction, sleep, and mood.
• How does the endocrine system work alongside the nervous system?

  The endocrine system works alongside the nervous system to control long-term processes such as growth, development, and reproduction.
• What are the three types of intercellular communication in the endocrine system?

  The three types are autocrine, paracrine, and endocrine communication.
• What is autocrine communication?

  Autocrine communication occurs between cells of the same type that must be in direct contact.
• What is paracrine communication?

  Paracrine communication uses chemical messengers to transfer information from cell to cell within a tissue.
• What is endocrine communication?

  Endocrine communication involves the release of hormones into the bloodstream.
• How do target cells respond to hormones?

  Target cells have receptors that bind to specific hormones.
• What are the three classes of hormones?

  • Amino acid derivatives
  • Peptide hormones
  • Lipid derivatives
• What are examples of amino acid derivative hormones?

  Examples include thyroid hormones and catecholamines.
• What are examples of peptide hormones?

  Examples include insulin, antidiuretic hormone, oxytocin, and growth hormone.
• What are examples of lipid derivative hormones?

  Examples include eicosanoids like prostaglandin E and steroid hormones like oestrogen and androgen.
• How do hormones circulate in the bloodstream?

  Hormones enter the bloodstream and circulate freely or are bound to carrier proteins.
• What happens to freely circulating hormones?

  Freely circulating hormones are active for only a short period of time.
• How are hormones inactivated?

  Hormones can be inactivated by binding to receptors, being absorbed and degraded by the liver or kidneys, or being degraded by enzymes in the blood.
• What is the role of hormone receptors?

  Binding of hormones to their target receptor modifies cellular activities.
• What are the two broad types of hormone receptors?

  The two broad types are plasma membrane receptors and intracellular receptors.
• Which hormones bind to plasma membrane receptors?

  Adrenaline, noradrenaline, dopamine, and peptide hormones bind to plasma membrane receptors.
• What is the function of second messengers in hormone action?

  Second messengers are used to amplify the signal and trigger cellular responses.
• What happens when a hormone binds to a plasma membrane receptor?

  The hormone binds to the receptor on the extracellular side of the membrane and activates a G protein.
• What is the role of adenylate cyclase in hormone action?

  Adenylate cyclase converts ATP into cAMP, which functions as a second messenger.
• How does cAMP function in cellular signaling?

  cAMP activates kinases that cause phosphorylation and activation of other proteins.
• What is the role of phospholipase C (PLC) in hormone action?

  PLC triggers an enzyme cascade starting with the production of diacylglycerol (DAG) and inositol triphosphate (IP3).
• What does IP3 do in hormone signaling?

  IP3 triggers the release of Ca ions from the endoplasmic reticulum.
• What is the function of calmodulin in hormone action?

  Calmodulin binds to Ca ions and activates cytoplasmic enzymes.
• How do steroid hormones act on cells?

  Steroid hormones diffuse across the cell membrane and bind to intracellular receptors, activating or deactivating specific genes.
• What are the major endocrine organs?

  • Pituitary gland
  • Thyroid gland
  • Parathyroid gland
  • Adrenal gland
  • Pineal gland
  • Pancreas
• What is the function of the pituitary gland?

  The pituitary gland is the major endocrine gland that controls the release of hormones from other glands.
• What are the two lobes of the pituitary gland?

  The two lobes are the anterior lobe and the posterior lobe, which differ in function.
• How is the release of hormones from the pituitary gland controlled?

  The release of hormones from the pituitary gland is controlled by the hypothalamus.
• What is the function of thyroid-stimulating hormone (TSH)?

  TSH triggers the release of thyroid hormones from the thyroid gland.
• What does adrenocorticotropic hormone (ACTH) control?

  ACTH controls the release of steroid hormones from the adrenal cortex.
• What are gonadotrophins?

  Gonadotrophins include follicle-stimulating hormone (FSH) and luteinising hormone (LH).
• What is the function of prolactin (PRL)?

  Prolactin stimulates milk production in the mammary glands.
• What does growth hormone (GH) do?

  Growth hormone stimulates growth and cell reproduction.
• What is the function of melanocyte-stimulating hormone (MSH)?

  MSH stimulates the production of melanin in the skin.
• What is the function of antidiuretic hormone (ADH)?

  ADH acts on the kidneys to retain water and decrease urination.
• What does oxytocin do?

  Oxytocin stimulates contraction of the uterine wall and the release of milk.
• Where is the thyroid gland located?

  The thyroid gland curves over the trachea, inferior to the thyroid cartilage.
• What is produced in the thyroid gland?

  The thyroid gland produces thyroid hormones.