Endocrine System Notes PDF

so Ny_Its_f Secretary cells of endocrine glands release their products signaling molecules called hormones, uptake by capillaries and distribution throughout the body  foundunderthebrain the pituitary actually consists of...

so Ny_Its_f Secretary cells of endocrine glands release their products signaling molecules called hormones, uptake by capillaries and distribution throughout the body  foundunderthebrain the pituitary actually consists of two glands:- originatefrombrain Itsy A) neurohypophysis: Pars nervosa de ffftihat.am ren B) adenohypophysis: month fee Pars distalis Pars tuberalis fromanteriorpart intermedia pars  Left field A) Stroma: - Capsule, reticular C.T, C.T septa and C If containing sinusoidal capillaries.contain bloodvessle IIII B) Parenchyma: callproduce hormones lovestain 1- Chromophils: Acidophils (35%)&Basophils (15%) ds T___dierested 2- Chromophobes: (50%) are poorly stained tree hatestain A) Acidophils: attester acidophilic granules in cytoplasm. Function:- Somatotrophs ( secrete growth hormone) of Mammotrophs (secrete prolactin hormone)  B) Basophils differed basophilc granules in cytoplasm Function: there are 3 types of basophils: Thyrotrophs (secrete TSH) Corticotrophs (secrete ACTH & MSH) Effffderstthers Gonadotrophs (secrete FSH, LH = ICSH)  betweenthem fixanyproblemhappeninchromophilsandpresent Small and polygonal and round nucleus with poor stained in cytoplasm Function: - Partially degranulated chromophils - Reserve or stem cells  FF.FM o Consists of a thin layer of cuboidal cells with fenestrated blood capillaries in- between  Freed  Structure of pars nervosa:  1- Unmyelinated nerve fibers  2- Herring bodies  3- Fenestrated blood capillaries  4- Pituicytes  Function: Storage and release of a Oxytocin It plays a role sexual reproduction Herring Bodies  htitss ead  Tumor of anterior pituitary may compress e the optic nerve and lead to blindness.  Tumor composed mainly leads to gigantism in children, and acromegaly in adults.  Excessive prolactin in males cause breast enlargement and impotence (inability to have erection during sexual activity). I  iodineisthemostimportantmineral for thyroid Stroma : msn.mn Capsule - C.T septa – reticular C.T In Parenchyma:- secretory cells Two lobes connected By a narrow isthmus  teh 1 Ovoid -(Thyroglobulin)..si ii i s Wall of follicle: - Follicular cells: Cubical with central rounded nucleus. - Secrete T3 & T4 hormones foundbetweenfollicularcells clearcell - Parafollicular cells: (c cells) - Secrete calcitonin hormone: decrease bone osteoclast activity, and lower the blood F calcium level. f f  1 17 dec In thyrotoxicosis there is increase in follicular cells number and thyroxine secretion.  Iodine deficiency goiter occur with a diet low in iodine and leads to hypothyroidism.  Myoxedema: hypothyroidism leads to IoT fatigue, sleeping, muscular and mental 8 sluggishness..  In Graves disease: autoimmune disease. There is exophthalmic goiter and hyperthyroidism  General appearance: - Four small glands, behind the thyroid gland  d  Structure: - Stroma: capsule, septa, and reticular C.T  so  - Parenchyma: 1) Chief cells (secrete parathyroid hormone) Ca 2) Oxyphil cells Iannered 3) Some fat cells  General appearance: - Two, one above each kidney free - Formed of peripheral cortex and central medulla  Structure: anothername trabecular A a- Stroma (1- Capsule 2- Septa 3- Reticular C.T) b- Parenchyma (1- Adrenal cortex 2- Adrenal medulla) 8  otal Cortex formed of Three zones Zona golmerulosa Zona fasiculata Zona reticularis long 5 80th  helpregulatwomen hormone after menopausal  Zona Glomerulosa: Pyramidal or columnar. Secrete mineral corticoids, mainly aldosterone EEÉÉcue theyenlarge  f Zona Fasiculata: Polygonal or cubical and nucleus May be binucleated, secrete 08 __ glucocorticoids e (cortisone)andsomealdosterone  Zona Reticularis: Smaller and some cells have pyknotic nuclei, secrete androgens dark Produce all hormone in the ovary after menopausal. ____ e  Infested  Have profuse blood supply in-between cell cords.  Structure: two types of cells 1) Chromaffin cells 2) Autonomic ganglion cells innervated by preganglionic sympathetic neurons.  Chromaffin cells: t - Considered modified sympathetic ganglia cells, lost their axons and dendrites. - Cells secret epinephrine (80%) or norepinephrineif ed (20%)  Autonomic ganglion cells: Scattered between chromaffin cells  in  Called pineal gland or third eye (function affected see by light). › Stroma: - 1- Capsule 2- Septa 3- Reticular C.T › Parenchyma:Pinealocytes (secretory cells) › secrete Melatonin (by night), and form e serotonin (precursor of melatonin by day)