ENDO REPRO

• An endocrine disrupter interferes with the action of the endocrine system, the system that regulates body responses by way of hormones.
• a synthetic chemical that has been in use since the 1950s.

  bisphenol A (BPA)
• the intercellular signaling molecules of the endocrine system

  Hormones
• Each endocrine gland consists of many hormone-secreting epithelial

  cells embedded in connective tissue.
• hormones affect cells by binding to receptor proteins
• Vertebrate endocrine and nervous systems are so closely linked that scientists sometimes refer to them collectively as the neuroendocrine system. 
• The hypothalamus is a major control center for both the nervous and endocrine systems, and most organs respond to signals from both systems.
• two categories of hormones

  derived from amino acids, and derived from cholesterol
• The hormones derived from amino acids include amine hormones (which are modified amino acids), peptide hormones (which are short chains of amino acids), and protein hormones (which are longer chains of amino acids). 
• Peptide and protein hormones are polar, hydrophilic molecules.
• a molecule that forms inside a cell in response to the binding of a signaling molecule to a receptor in the plasma membrane.

  second messenger
• steroid hormones can enter the nucleus and directly influence gene expression. These hormones, which are derived from cholesterol are non polar and lipid soluble.
• All hormone receptors are proteins.
• can alter receptor structure in a way that alters or prevents their function.

  Mutations
• located deep inside the forebrain, is the body's main regulator of the internal environment

  hypothalamus
• a pea-sized endocrine gland with two lobes that differ somewhat in their function.

  pituitary gland
• The posterior lobe of the pituitary secretes hormones that were made inside the hypothalamus.
• The anterior lobe makes its own hormones and releases them in response to hormones from the hypothalamus.
• targets kidney cells and discourages the loss of water in the urine.

  Antidiuretic hormone (ADH)
• targets cells in the reproductive tract and mammary glands (breasts)

  Oxytocin (OCT)
• meaning they encourage their target cells in the pituitary to secrete hormones.

  releasing hormones
• which reduce secretion of hormones by their target cells.

  inhibiting hormones,
• stimulates the adrenal glands to reduce cortisol

  Adrenocorticotropic hormone (ACTH)
• causes the thyroid gland to secrete thyroid hormone. 

  Thyroid-stimulating hormone (TSH)
• affect sex hormone secretion and production of gametes by gonads (a males testes or a female's ovaries).


  Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
• targets cells in the breast's mammary glands. It contributes to breast development at puberty and governs milk production after a woman gives birth.

  prolactin (PRL)
• hormone that promotes growth and development throughout the body,

  growth hormone (Gh)
• GH production declines with age
• occurs when the body produces too little GH or receptors do not respond to it properly during childhood.

  Pituitary dwarfism
• Excessive GH secretion during childhood causes gigantism.
• a condition in which bones and cartilage thicken

  acromegaly,
• an injectable prescription drug that is made in genetically engineered bacteria.

  Recombinant human growth hormone (rhGH)
• melatonin secretion typically peaks at about 2 A.M. while we are asleep.
• pinecone-shaped pineal gland lies deep inside the brain
• Physiological change that repeats itself on an approximately 24-hour cycle. 

  circadian rhythm
• Pineal gland hormone that regulates sleep-wake cycles and seasonal changes.

  melatonin
• suppresses melatonin secretion more effectively than light of other wavelengths

  Blue light
• The thyroid gland lies at the base of the neck, in front of the trachea.
• two amine hormones (triiodothyronine and thyroxine) that we will refer to collectively as thyroid hormone.
• Thyroid hormone acts throughout the body to increase basal metabolic rate (the rate at which the body uses energy to maintain itself).