Endocrine System

• Endocrine system


  Maintenance of homeostasis, which involves growth, maturation, reproduction, metabolism, and human behavior
• Hormones


  Control the internal environment of the body from cellular level to the organ level of organization<|>Control cellular respiration, cellular growth, and cellular reproduction<|>Help regulate metabolism, water and electrolyte concentrations in cells, growth, development, and reproductive cycles
• Negative feedback loop


  Corrects the stimuli and helps in maintaining homeostasis
• Endocrine glands


  Ductless glands that secrete hormones directly into the bloodstream
• Hypothalamus


  Sends directions via chemical signals (neurotransmitters) to the pituitary gland<|>Nerve cells in the hypothalamus produce chemical signals called releasing hormones and releasing inhibitory hormones<|>CRH – the hormone that stimulates the other glands to produce/secrete their hormone
• Pituitary gland


  Location: Below the hypothalamus of the brain
• Anterior pituitary lobe


  • Produces 7 hormones
• Growth hormone (GH)


  Stimulates cell metabolism in most tissues of the body<|>Stimulates the growth of bones, muscles, and organs<|>Increase protein synthesis and the breakdown of fats and carbohydrates<|>Releases SOMATOMEDIS or Insulin-Like Growth Factors (IGF)<|>Peak secretion of GH occur during periods of: SLEEPING, EXERCISE, and FASTING<|>Growth is also influenced by nutrition, genetics, and sex hormones during puberty<|>Increase the cellular uptake of amino acids and protein synthesis in many organs<|>Stimulates the breakdown of triglycerides<|>Stimulates the breakdown of glycogen
• Thyroid-stimulating hormone (TSH)


  Stimulates the thyroid gland to produce its hormones (T3, T4, Calcitonin)
• Adrenocorticotropic hormone (ACTH)


  Stimulates adrenal cortex to secrete its hormone; CORTISOL
• Melanocyte-stimulating hormone (MSH)


  Increase the production of melanin in melanocyte of the skin, causing a deepening pigmentation or darkening of skin
• Follicle-stimulating hormone (FSH)


  Stimulates the development of follicle in the ovaries – female<|>Stimulates the production of sperm cells – male
• Luteinizing hormone (LH)


  Stimulates the ovulation and production of progesterone, helps maintain pregnancy – female<|>Stimulates the synthesis of testosterone and production of sperm cells – male
• Lactogenic hormone (LTH) | Prolactin (PRL)


  Stimulates lactation or production of milk in the mammary gland after pregnancy
• Posterior pituitary lobe


  Produces 2 hormones<|>Consists primarily of nerve fibers and neuroglial cells
• Antidiuretic hormone (ADH) | Vasopressin


  Maintains the body's water balance by ordering the renal tubules to reabsorb water<|>Causes the kidney to retain water<|>Reduces diuresis – less urine / increase urine retention<|>Maintains the blood when bleeding, restoring the blood volume<|>Compensates the loss of fluid
• Oxytocin


  Stimulates contraction of smooth muscle in the lining of the uterus when giving birth or having sex<|>Stimulates milk ejection or lactation (Lactation: LH & Oxytocin)
• Thyroid gland


  Consists of two lobes connected by isthmus
• T3 Triidothyronine


  Contains 3 iodine atom
• T4 Tetraiodothyronin or Thyroxine


  Contains 4 iodine atom
• Thyroid hormones


  Regulates the metabolism of the body (oxygen, carbohydrates, fats, and proteins)<|>Necessary for normal growth and development and nervous system maturation<|>Increase the rate of carbohydrate and lipid breakdown into energy molecules
• Calcitonin


  Thyroid gland releases calcitonin when the calcium in the blood is high, because calcitonin decreases the blood calcium by bone reabsorption<|>Involved in regulating the calcium and phosphate in the blood
• Parathyroid gland


  Four pea size gland located at the back of the thyroid gland
• Parathyroid hormone (PTH)


  Inhibits the activity of osteoblast and causing osteoclast to breakdown bone matrix tissue (osteoblast: bone makers, osteoclasts: bone breakers)<|>Releases calcium and phosphate ions into the blood<|>Causes the kidneys to conserve blood calcium and stimulates intestinal cell to absorb calcium from digested food in the intestine
• Pineal gland


  Produces melatonin and serotonin
• Melatonin


  Helps us relax and sleep
• Serotonin


  Happy hormone (found in bananas)<|>Body's natural pain reliever
• Adrenal gland


  Smalls glands found atop of each kidney
• Adrenal medulla


  Inner part of the adrenal gland<|>Produces large amounts of adrenaline hormones (epinephrine: vasodilation/increases heart rate, norepinephrine: vasoconstrictor/increases blood pressure)
• Adrenal cortex


  Has three tissue layers
• Zona glomerulosa


  Produces a mineralocorticoid; ALDOSTERONE<|>For the reabsorption of sodium<|>Helps maintain blood when bleeding
• Zona fasciculata


  Produces a glucocorticoid; CORTISOL
• Cortisol


  Helps control blood sugar levels, regulate metabolism, help reduce inflammation, and assists with memory retention<|>Has a controlling effect on salt and water balance, and helps control blood pressure<|>Makes us eat a lot<|>A type of steroid<|>Being released when you are under stress<|>Increase blood-sugar<|>Inhibits the immune and inflammatory reaction<|>Needed to make capillary membrane stable
• Zona reticularis


  Innermost of the walls<|>Involved in secretion of different sex hormones (ANDROGENS/TESTOSTERONE)
• Hormones that increase blood sugar level

  • Cortisol
  • Glucagon
  • Growth hormone
• Hormones that help in retaining blood when bleeding

  • Antidiuretic hormone (ADH)
  • Aldosterone
• Glycogenolysis


  The liver converts glycogen into glucose
• Gluconeogenesis


  The liver converts fats and lipids into glucose