ENDOCRINE SYSTEM ANSHUMAN PRAJAPATI - PowerPoint Presentation

1. ENDOCRINE SYSTEMANSHUMAN PRAJAPATIM. PHARM, PHARMACOLOGY

2. IntroductionThe endocrine system controls body activities by releasing mediators, called hormones. A hormone (to excite or get moving) is a mediator molecule that is released in one part of the body but regulates the activity of cells in other parts of the body. Most hormones enter interstitial fluid and then the bloodstream. The circulating blood delivers hormones to cells throughout the body. Both neurotransmitters and hormone exert their effects by binding to receptors on or in their “target” cells.

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4. IntroductionExocrine glands (exo-outside) secrete their products into ducts that carry the secretions into body cavities, into the lumen of an organ, or to the outer surface of the body. Exocrine glands include sudoriferous (sweat), sebaceous (oil), mucous, and digestive glands. Endocrine glands (endo-within) secrete their products (hormones) into the interstitial fluid surrounding the secretory cells rather than into ducts. From the interstitial fluid, hormones diffuse into blood capillaries and blood carries them to target cells throughout the body.

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12. Basic Feedback mechanism of HormoneHypothalamus (Detector)↓Release hormones↓Anterior lobe of Pituitary glands (Control centre)↓Trophic hormones to the endocrine glands↓Target gland (Effector)↓Raised blood level of target gland hormone↓Consumption of hormone↓Lowered blood level of target gland hormone

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14. Feedback mechanism of OxytocinIn labor, uterine contractions forces the baby’s head into cervix ↓+Stretch receptors in uterine cervix (Detector)↓Nerve Stimulation or nerve impulse generation↓Hypothalamus & Posterior lobe of Pituitary glands (Control centre)↓Release of oxytocin ↓+Uterine smooth muscles (Effector)↓Stronger contractions forces the baby’s head further into the cervix↓↓Inhibition occurs after delivery when uterine contractions no longer stretch the cervix

15. Feedback mechanism of Thyroid hormonesExercise, stress, malnutrition, low blood glucose level, sleep ↓+Hypothalamus (Detector)↓Thyrotropin releasing hormone (TRH)↓Anterior lobe of Pituitary glands (Control centre)↓Thyroid stimulating hormone (TSH) ↓+Thyroid gland (Effector)↓Thyroxine (T4) & Tri-iodothyronine (T3)↓Raised level of T3 & T4↓Cellular uptake and metabolism of hormones by most body cells↓Lowered level of T3 & T4

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19. Pineal glandThe pineal gland (pinecone shape) is a small endocrine gland attached to the roof of the third ventricle of the brain at the midline.The gland consists of masses of neuroglia and secretory cells called pinealocytes. The pineal gland secretes melatonin, an amine hormone derived from serotonin. Melatonin appears to contribute to the setting of the body’s biological clock, which is controlled by the suprachiasmatic nucleus of the hypothalamus. As more melatonin is liberated during darkness than in light, this hormone is thought to promote sleepiness. During sleep, plasma levels of melatonin increase tenfold and then decline to a low level again before awakening. Small doses of melatonin given orally can induce sleep and reset daily rhythms, which might benefit workers whose shifts alternate between daylight and nighttime hours.

20. Thymus glandThe thymus is located behind the sternum between the lungs. The hormones produced by the thymus—thymosin, thymic humoral factor (THF), thymic factor (TF), and thymopoietin—promote the maturation of T cells (a type of white blood cell that destroys microbes and foreign substances) and may retard the aging process.

21. Disorders of endocrine systemDwarfismGigantismAcromegalyDiabetes insipidusCongenital hypothyroidismGrave’s diseaseGoiterAddison’s diseaseDiabetes mellitusGynaecomastia

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