Endocrine glands (BBMS, 1213).pptx

ENDOCRINE GLAND A/Prof. Dr. Thida Depending on the duct system, all glands of the body are classified either as exocrine or endocrine. Exocrine glands secrete their products into ducts that empty at the surface of covering or lining epithelium. The secretions of exocrine gla...

ENDOCRINE GLAND A/Prof. Dr. Thida Depending on the duct system, all glands of the body are classified either as exocrine or endocrine. Exocrine glands secrete their products into ducts that empty at the surface of covering or lining epithelium. The secretions of exocrine glands include mucous, sweat, oil, earwax, milk, saliva and digestive enzymes. The secretions of endocrine glands enter the interstitial fluid and then diffuse into the bloodstream without flowing through a duct. These secretions, called hormones, regulate the many metabolic and physiological activities to maintain homeostasis. Glands with Duct  exocrine gland glands without duct  endocrine gland (secretion-hormone) Hormone-regulation of metabolism -reproduction -growth The system comprises: (1)Endocrine organ of cranial cavity -pituitary gland -pineal body or gland (2) Endocrine organ in the neck region -thyroid gland, parathyroid gland, thymus (3) Endocrine organ in the abdominal cavity -pancreas, -supra-renal or adrenal gland (4) Gonadal endocrine organ -ovary in the female -testis in the male (1) Pituitary gland (hypophysis) -small gland about the size of pea -attach by a stalk-infundibulum to the hypothalamus above -rest on pituitary fossa of sphenoid bone 2 lobes-anterior lobe(adenohypophysis) -posterior lobe (neurohypophysis) Hormone produced by anterior lobe (FLATGP) FSH(follicular stimulating hormone) -growth of ovarian follicles LH (leuteinizing hormone) -for the final stage of follicle maturation -induce the shedding of the oocyte ACTH (adrenocorticotrophic hormone) -stimulate the adrenal cortex to functional activity TSH (thyroid stimulating hormone) -stimulate thyroid gland GH - affects the rate of skelatal and visceral growth Prolactin - production of milk secretion Disturbances of the lobe- -dwarfism, giantism, infantism, excessive obesity, other manifestation association with growth and sex Hormone produced by posterior lobe -oxytoxin-stimulate contraction of uterus -ADH -production of urine by the kidney (2) Pineal body and gland -resembles a miniature pine cone -projects backward from the back of the roof of 3rd ventricle -hormone from pineal gland  Melatonin -melatonin helps day-night sleep patterns. (3) Thyroid gland -lies in the neck -H shape , consists of 2 lateral lobes connected by isthmus -consists of thyroid follicle containing thyroid hormone (T3 &T4) T3 & T4 (thyroxine & tri-iodothyronine) -effects the metabolism of carbohydrates, protein & lipids -increase hormone-hyperthyroidism -decrease hormone- hypothyroidism Congenital deficiency or absence of thyroid gland-result in mentally defective dwarf (cretin) Parafollicular C cell-produce calcitonin which reduce the blood Calcium level Enlargement of thyroid gland - goiter (4)Parathyroid gland -2 pairs of yellowish brown gland embedding in the posterior surface of thyroid gland -small ovoid bodies -produce parathyroid hormone or parathormone-which increase blood calcium level hormone-bones become soft or extremely brittle (5)Thymus gland -extend behind the sternum (retrosternal organ) -produce thymosin- plays an important role in the development of body’s immune system -thymosin - stimulates T cell production (6)Supra-renal or adrenal gland -2 yellowish organs that lie on the upper poles of the kidneys -2 portions-outer cortex -inner medulla Adrenal medulla -secrete -adrenalin or epinephrine -nor-adrenalin or nor-epinephrine -increase heart rate & blood pressure Adrenal cortex consists of (a) Zona glomerulosa-secrete mineralocorticoid (aldosterone)-conserve sodium ions & water in the body (b) Zona fasciculate-secrete glucocorticoid (cortisol)- blood glucose level for carbohydrate metabolism (c) Zona reticularis-secrete gonadocorticoid (androgen, estrogen, progestrone & steroid hormones) (7)Pancreas -both exocrine & endocrine function -endocrine gland-release cell-glucagon- blood glucose level cell-insulin -blood glucose level insulin –vital to the proper metabolism carbohydrate  insulin- blood glucose level-DM (8)Gonads Testes-produce androgen & testosterone -for the development & maintenance of male secondary sex characteristics Ovaries- produce estrogen & progesterone estrogen-for the development & maintenance of female secondary sex characteristics progesterone-maintains the uterine lining for pregnancy Regarding the adrenal medulla: A They secrete epinephrine and norepinephrine. B They comprise the outer part of the adrenal gland. C It is not under the control of the hypothalamus. D Acts on its own. Regarding the gonadal glands: A comprises the ovary in the female and testes in the male. B the ovaries produce only oestrogen. C the testes lie in the abdomen. D the male hormone is called progesterone. The male hormone A is oestrogen. B regulates the production of sperms in the testes. C acts on the body since birth. D is not responsible for the appearance of secondary sexual characteristics in the male. The ovaries A produce only oestrogen. B produce only progesterone. C produce both oestrogen and progesterone. D secretion of hormones is not under the control of hypothalamus. Thank you for your attention!