Endocrine

• Endocrine System


  • Major regulatory system that influences metabolism, growth, reproduction, and many other functions
  • Consists of glands such as the pituitary that secrete hormones
  • Has similar functions with the nervous system
  • Has chemical (hormones) control over the rest of the body systems
  • Has ductless glands
• Endocrine Glands


  • Hypothalamus
  • Pituitary gland (Base of the brain)
  • Pineal body
  • Thyroid
  • Parathyroid gland (Posterior part of thyroid)
  • Thymus
  • Adrenal glands
  • Pancreas (Islets of Langerhans)
  • Ovaries (Female)
  • Testes (Male)
• Endocrine


  "Within and to separate"
• Endocrine System


  • Intercellular chemical signals (hormones) are produced within and secreted from endocrine glands but the chemical signal have effects at locations that are away from the endocrine glands that secrete them
  • These hormones are then transferred through the circulatory system (blood vessels)
  • The endocrine glands are ductless
• Hormones


  "To Set Into Motion"
• Hormones


  • Intercellular chemical signal, produced in minimum amounts that is secreted into the interstitial fluid and enters the circulatory system to be transported some distance
  • Acts on tissues (target tissues) at another site in the body to influence their activity in a specific way
  • The capillaries carry hormone along with the blood
  • These hormones are puzzle- like
  • The target cells have receptors that have the same shape as the hormone so it is like a lock and key relationship
• Chemical Categories of Hormones


  • Proteins, Peptides And Amino Acid Derivatives
  • Lipid Hormones
• Proteins, Peptides And Amino Acid Derivatives


  • Bind to membrane bound receptors
  • Examples: GH, LH, ADH, prolactin, epinephrine
• Lipid Hormones


  • Steroid hormones
  • Examples: Estrogen, testosterone, eicosanoids, prostaglandins
• Endocrine Glands


  Glands that secrete hormones directly into the bloodstream
• Hormones


  Chemical messengers secreted by endocrine glands that regulate the activity of target tissues
• Target Tissues


  Tissues that respond to the hormones secreted by endocrine glands
• Pituitary Gland (Master Gland)


  • Produces majority of the hormones
  • The hormones it secretes has control over other endocrine glands
• Growth Hormone


  Promotes protein synthesis, breakdown of lipids, and release of fatty acids
• Hyper secretion of Growth Hormone

  Gigantism
• Hypo secretion of Growth Hormone

  Dwarfism
• Thyroid-Stimulating Hormone (TSH)


  Increases thyroid hormone secretion (thyroxine and triiodothyronine)
• Hyper secretion of TSH

  Hyperthyroidism
• Hypo secretion of TSH

  Hypothyroidism
• Adrenocorticotropic Hormone (ACTH)


  Increases secretion of glucocorticoid hormones such as cortisol, increases skin pigmentation at high concentrations
• Melanocyte-Stimulating Hormone (MSH)


  Increases melanin production to make skin darker
• Luteinizing Hormone (LSH) Or Interstitial Cell-Stimulating Hormone (ICSH)


  Promotes ovulation and progesterone production (ovary), testosterone synthesis and support for sperm cell production (Testis)
• Follicle Stimulating Hormone (FSH)


  Promotes follicle maturation and estrogen secretion in ovary; sperm cell production in testis
• Prolactin


  Stimulates milk production and prolong progesterone secretion in following ovulation and pregnancy in women, increases sensitivity to LH in males
• Antidiuretic Hormone


  Conserves water, constricts blood vessels
• Oxytocin


  Increases uterine contractions, increases milk letdown from mammary gland
• Thyroid hormones


  • Target tissues: most cells of the body
  • Function: increases metabolic rates
• Calcitonin


  • Target tissue: primarily bone
  • Function: decreases rate of bone breakdown, prevents large increase in blood ca2+ levels following a meal
• Parathyroid Hormone


  • Target tissue: bone, kidney
  • Function: increases bone breakdown by osteoclasts, increases vit d synthesis, maintenance for normal blood calcium levels
• Epinephrine Mostly, Some Norepinephrine


  • Target tissue: heart, blood vessels, liver, fat cells
  • Function: increases cardiac catapult, increases blood flow to skeletal muscles and heart, increase release of glucose and fatty acids into blood, prepares the body for physical activity
• Mineralocorticoids (Aldosterone)


  • Target tissue: kidneys; to lesser degree intestine and sweat glands
  • Function: increases rate of sodium transport into body; increase rate of potassium excretions; secondarily favor water retention
• Glucocorticoid (cortisol)


  • Target tissue: most tissue (liver fat, skeletal muscle, immune tissues)
  • Functions: increases fat and protein breakdown, increases glucose synthesis from amino acids, increase blood nutrient levels inhibit inflammation and immune response
• Adrenal Androgens


  • Target tissue: most tissue
  • Functions: insignificant in males; increases female sexual drive, growth of pubic and axillary hair
• Insulin


  • Target tissue: especially liver, skeletal muscle, adipose tissue
  • Function: increases uptake and use of glucose and amino acids
• Glucagon


  • Target tissue: primarily liver
  • Function: increases breakdown of glycogen and release of glucose into the circulatory system
• Testosterone


  • Target tissue: most tissues
  • Function: aids in sperm cell production, maintenance of functional reproductive organs, secondary sexual characteristics, sexual behavior
• Ovaries


  Reproductive organ
• Estrogen and progesterone


  Hormones produced by the ovaries
• Target tissue of estrogen and progesterone

  • Most tissue
• Function of estrogen and progesterone

  Aid in uterine and mammary gland development and function, external genitalia structure, secondary sexual characteristics, sexual behavior, menstrual cycle