Endocrine System Histology 2022 PDF

Endocrine system – presentation’s plan HISTOLOGY - ENDOCRINE SYSTEM- Endocrine system vs nervous system Endocrine system’s function and its organization What are hormones?? Hypothalamo-hypophyseal system Hypophysis: adenohypo...

Endocrine system – presentation’s plan HISTOLOGY - ENDOCRINE SYSTEM- Endocrine system vs nervous system Endocrine system’s function and its organization What are hormones?? Hypothalamo-hypophyseal system Hypophysis: adenohypophysis, neurohypophysis Thyroid Parathyroid Department of Histology and Embryo Adrenal glands Pomeranian Medical University in Sz Pancreas – Islets of Langerhans Pineal gland  NERVOUS SYSTEM VS ENDOCRINE SYSTEM Dain Ingeb  ENDOCRINE SYSTEM GLANDS (the pituitary, thyroid, parathyroid, suprarenal glands, the pineal body) g CLUSTERS OF ENDOCRINE CELLS (the islets of Langerhans in the pancreas) INDIVIDUAL ENDOCRINE CELLS SCATTERED AMONG THE EPITHELIAL LINING OF THE GASTROINTESTINAL AND RESPIRATORY TRACTS (diffused neuroendocrine system cells)  HORMONES chemical substances that act on target tissues/organs/cells target tissues/organs/cells 🡪 cells with receptors -environment - receptors: translate the signal from inner/outer millieu into the „cell language” which leads to its response (contraction, ions, hormones, mucus releasing, movement, mitosis etc.)  HYPOPHYSIS (PITUITARY GLAND) Small gland (weights about 0,5 g). In a cavity of the sphenoid bone – the sella turcica.  Hypophysis HYPOPHYSIS Neurohypophysis: Pars nervosa Neural stalk stem median eminence Adenohypophysis: Pars distalis Pars intermedia Pars tuberalis  s HYPOTHALAMO-HYPOPHYSEAL SYSTEM Oxytocin: Social bunding 1. Peptides produced by aggregates of secretory neurons (supraoptic, paraventricular nuclei) in the hypothalamus 🡪 pars nervosa (oxytocin, antidiuretic hormone) Waterbalance -> 2. Peptides produced by neurons of the dorsal medial, ventral medial and infundibular nuclei of the hypothalamus. Stored in the median eminence 🡪 adenohypophysis (hormones releasing factors, hormones inhibiting factors) 3. Proteins and glycoproteins produced by cells of pars distalis 🡪 trophic hormones (blood capillaries) Saders Harm rule Hypte-Medion even Oxytocin inhit  HYPOTHALAMO-HYPOPHYSEAL SYSTEM Internal carotid artery: Superior hypophyseal artery Primary capillary plexus Secondary capillary plexus Hypophyseal veins Inferior hypophyseal artery  ⑧ 10. MRH/MIH MSH SKIN AstH-> Mineralcoreaids/oluocontrols  HORMONES OF THE ADENOHYPOPHYSIS SOMATOTROPIN STH (GROWTH PROLACTIN (PRL) HORMONE, GH) Secreted by the whole life cycle day / night Stimulation of the corpus luteum to progesterone secretion Stimulation of proliferation of chondroblasts growth plate - IGF I (excessive secretion in childhood - gigantism, increased Initiation of the lactation releasing after the completion of bone growth - acromegaly (overgrowth of cells eosinophils and eosinophilic pituitary Oversecretion of the PRL in women can cause Balanced adenoma) infertility -no ovulation, no menstruation. level of Pro Estra Stimulation protein synthesis in a cell Reduction of the fertility and libido in men. Affection of the metabolism of carbohydrates and fats A problem associated with hyperprolactinemia is galactorrhoea (spontaneous flow of milk from the The influence of GH - enhancement of lipolysis breast, unassociated with childbirth or nursing, in cells fatty acids - activates lipoprotein lipase patients of both sexes). men – gynecomastia (noncancerous increase in the Human somatropin - treatment of pituitary size of male breast tissue) dwarfism  ↑ Seal Hormonesof the aderophysis HORMONES OF THE ADENOHYPOPHYSIS Isresonat GONADOTROPINS THYREOTROPIN (TSH) Increasing the weight and blood flow in the Follitropin (FSH) thyroid site Regulation of ovarian function (folliculogenesis) Stimulating synthesis and secretion of thyroid hormones Regulation of Sertoli cells function in male gonad test25 Increasing radioiodine uptake by thyroid Reduction of iodine in the thyroid gland by stimulating secretion of hormones Lutropin - luteinizing hormone (LH) ↑ Regulation of ovarian function (steroidogenesis Regulation the morphological changes of in ovarian follicles and corpus luteum) legedig the thyroid follicular cells and colloid Regulation of Leydig cell function in prostate - Affects the metabolism of adipose tissue – interstitial nucleus (synthesis of testosterone) /-> leydigs lipolysis ISH Sertoli  HORMONES OF THE ADENOHYPOPHYSIS ADRENOCORTICOTROPIC HORMONE (ACTH ) affects the activity of the adrenal cortex increasira Pre stimulation of cell proliferation fasciculata and reticularis layer -> ↳urmal stimulation of the synthesis of adrenal hormones, mainly glucocorticoids increasing glucose metabolism in the adrenal gland - activation of enzymes involved in the synthesis of steroid-you fasciculata of the adrenal cortex atimulation of melanocytes and activates lipolysis MELANOTROPIN (MSH), a protein hormone similar in structure to ACTH, overcoloration of the skin in Addison's disease may be associated with excessive release of melanotropin. LIPOTROPIN (LPH) - lipolytic action. Fut break sown into fatly weid & ol  Regulation Neural stimuli (+/-) (Cerebral cortex) (-) HYPOTHALAMUS TRH (+) I (-) PITUITARY TSH (+) THYROID T3, T4 TARGET CELLS HISTOLOGY OF HYPOPHYSIS  HISTOLOGY OF HYPOPHYSIS Pars intermedia Pars nervosa Pars distalis  PARS DISTALIS - 75% cords of epithelial cells (secretory granules) + capillaries + fibroblasts Traditional staining ◦ Chromophobes (C) ◦ Chromophils ◦ acidophils (A) ◦ basophils (B)  SECRETORY CELLS OF ADENOHYPOPHYSIS Cell type Hormone Stain affinity Release control Somatotrophs STH,GH acidophilic GHRH /SIH Mammotrophs PRL acidophilic PRH = TRH /PIH Gonadotrophs FSH, LH basophilic GnRH Thyrotrophs TSH basophilic TRH Corticotrophs ACTH basophilic CRH Melanotrophs MSH basophilic MRH/MIH PARS DISTALIS PARS INTERMEDIA - Secretory cells: basophilic cells (mainly corticotropic cells) Blood capillaries Fibroblasts Corticotropic cells produce peptide POMC (proopiomelanocortin) 🡪 adrenocorticotropin (ACTH), melanotropin (MSH) αβγ, lipotropin (LPH) βγ, endorphin β intermedia CCHWC  PARS TUBERALIS Funnel-shaped region surroundig the infudibulum of neurohypophysis Secretory cells: gonadotropins secreting cells Fibroblasts Blood vessels Gonadnok  Neurohypo physic Let ali NEUROHYPOPHYSIS Pars nervosa + neural stalk STRUCTURE Unlike the adenohypophysis – no secretory cells Unmyelinated axons (supraoptic and paraventricular nuclei) Pituicytes (glial cells) e Capillaries ❑ Neurosecretion of neurons accumulate at their endings (Herring bodies) ❑ Releasing: vasopresin and oxytocin+ neurophysin Vasopresin  NEUROHYPOPOHYSIS unmyelinated axons of neurons pituicytes capillaries  Newh HORMONS OF THE NEUROHYPOPHYSIS vao VASOPRESSIN (ADH) OXYTOCIN responsible for water management body myofibroblast contraction of the milk ducts secretion is increased: contraction of the myometrium and after bleeding oviducts (the effect of the presence of as a result of changes in the distribution of the amplified estrogen) circulating blood (eg. hypergravity) while the plasma osmolality is reduced after the administration of some pharmacological agents (nicotine) reduction or absence of ADH secretion - diabetes insipidus (excessive urination) Plasma oc melorly  THYROID GLAND In the cervical region, anterior to the larynx 2 lobes Originates from the endoderm of the initial portion of the primitive gut blood How -> T3 and Ty increase Extremely vascularized -> TSH ↳ - I endo - - ⑭ridd: - endo derm  THYROID GLAND Follicular structure epithelial cells colloid (3months) loose connective tissue capillaries  THYROID GLAND COLOID Function: synthesis and accumulation of hormones (T3, T4) T3 TY + =is clide Synthesis of thyreoglobulin Uptake of iodide (NIS) + tyrosine Activation of iodide (thyroid peroxidase) Iodination of tyrosine (thyroid peroxidase) Endu insic he cells I Storage (up to 3 months) profe Release of hormones - Ve labry Cells ◦ Endocytosis of thyreoglobulin Frau Stage -> ◦ Proteolytic digestion ↳ Protein Brook den  RELEASING OF HORMONES Stimulated by TSH Endocytosis mechanism – portions --> of coloid sterage Lysosomes and phagososmes (proteases) Liberation of T3 (10%), T4 (89%)  ⑳ C-CELLS (parafollicular cells) Between thyroid follicles Larger than thyroid follicular cells Synthesis and secretion of calcitonin Reducing in Calcium. PARATHYROID GLANDS Four small glands found on Thyroid glands Behind the thyroid gland Connective tissue capsule 🡪 support surrounded connective by a for elongated cordlike clusters of cells tissue capsule ofsell 5 clusters PARATHYROID GLAND  PARATHYROID GLANDS STRUCTURE cells the majority of - Chief cells (small, polygonal, slightly acidophilic cytoplasm)🡪 PTH - scre -> Same nuchi Oxyphil cells (large) -> butaburdentcyte Plasma Adypocytes (age) Adipose:fat ⑭ P capillaries I hiefC i 0x chief cells - - I arco: OxyzY Adipus- pille  PTH vs CALCITONIN PARATHYROID HORMONE CALCITONIN C-cells (thyroid gland) Chief cells (parathyroid gland) Receptors in osteoclasts Jinhibit Receptors in osteoblasts (a signal to Lowers concentration of Ca2+ in the blood produce osteoclast-stimulating factor) Increases concentration of Ca2+ Osteoclasts -- break bone tissue in the blood ca and release mineralsInto Blood · steoblast->osteoclast -> more Stream Both hormones regulate calcium metabolism, as proper concentration of calcium is essential for nerve and muscle function, PTH &calcitonin work together to maintain constant calcium level in blood. Homestasis -  PARATHYROID HORMON & CALCITONIN Regulate calcium metabolism The proper concentration of calcium is essential for nerve and muscle function, PTH &calcitonin work together to maintain constant calcium level in blood. 1. If blood calcium level drop, PTH causes the bones to release calcium and the kidneys to reabsorb more calcium from urine pTH-> kidney absorb more 2. If blood calcium level gets too high, calcitonin inhibits the release of calcium from bone.  to und on Kidneys ADRENAL GLANDS ▪ Paired organs (8g) ▪ Lie near the superior poles of kidneys ▪ 2 layers: contex adrenal medulla adrenal cortex Modulta  ADRENAL GLANDS Arteries: Capsule arteries Arfries -> capsules Cortical arteries Medulla Medullary arteries cortex Capsule or H nu  Note:rich capilluresnetwork run through &5Cells ⑧ & 8 VotiAdrenal: Columme Glone -s ADRENAL CORTEX 1. Zona glomerulosa: columnar/ pyramidal cells, closely packed cords surrounded by capillaries 2. Zona fasciculata: 1 or 2 thick straight cords that run at right angles to the surface + capillaries between them (spongiocytes ) found spongiocter 3. Zona reticularis: irregular cords of (small) cells Advenal cortex ⑱ Adrenal Cortex cortexi glomerulosa:coumar/pyramital sellssurround by capill fusciculati spongiocytes as sporgio cyte5 I  ADRENAL CORTEX Zona glomerulosa 15% Blood capillares Zona fasciculata ↑- 65% Sprigiryts 11 Zona reticularis 7% 156 E  Acidophilis e esinophilic kindle Acidophilic cytoplasm ADRENAL CORTEX STEROID SECRETING CELLS Acidophils -same rounded lipid droplets Round nucleus centrally located Lipid droplets 🡪 abundant SER No secretory granules (they synthesize and secrete steroid hormones upon demand) Adrenal does not store their productsin granules, but Secrete them upon request cat Cortexno stave  STEROIDOGENESIS All steroids derive from cholesterol Mineralocorticoids Glucocorticoids Sex steroids: estrogenes and androgens, DHEA- dehydroepiandrosterone  Adrenal cortex Three (3) typs of found cells within y glund X+H CORTICAL HORMONES I Stimulate Zona glomerulosa Zona fasciculata Zona reticularis RAA ACTH ACTH Mineralocorticoids Glucocorticoids (cortisol, Androgens (aldosterone) corticosterone) (dehydroepiandrosterone) Stimulate the reabsorbtion Affect the metabolism of Weak androgen. Can be of sodium by epithelial cells carbohydrates by converted into testosterone (mainly on the distal renal stimulating production of in several tissues tubules) glucose and the conversion Mineral antici E of glucose into glycogen - aldosterne - Glucucurlride Water and electrolites Metabolism of Supplement of sex steroids balance carbohydrate, lipids and DENAG corticostane proteins Mineral-soim providing the body du with energy stress L - testerac - ↳ - - Blood glycogen-> glucose -> water electrolyly ADRENAL MEDULLA HISTOLOGY area Adrenal Medulla Mislology  MEDULLA OF ADRENAL GLAND Polyhedral cells FEOCHROMOCYTES-arranged in cords/clumps supported by reticular fibers Aalvenaline FEOCHROMOCYTES E –epinephrine (80%) nextrans matter FEOCHROMOCYTES N- norepinephrien (20%) ↳ nerve growt of Releases and accumulates catecholamines - H Modified sympathetic postganglionic neurons - Secreted in response to intense emotional reactions (fright) stress Wicke relasing epinel >chromaffine Modified neurons s during not eph  Neural creb neuroectodermal origin (neural crest) mesodermal origin  ADRENAL GLANDS Structure ◦ Adrenal cortex ◦ Zona glomerulosa absurbtion ◦ mineralocorticoids ◦ Zona fasciculata of Nat ◦ glucocorticoids energy ◦ Zona reticularis ◦ androgens Testerne ◦ Adrenal medulla ◦ Epinephrine ◦ Norpinephrine ISLETS OF LANGERHANS  ISLETS OF LANGERHANS multihormonal endocrine microorgans small clusters connective tissue 1 million, more in the tail form pancreas Multihoravaal GHIH produced by Hypothalamus difference btw glycogen and glucagon ISLETS OF LANGERHANS Beta cells (insulin) 70% Beta - insulin Alpha->9ycoyer Alpha cells (glucagon) 20% Delta cells (somatostatin) 10% IGHIN PP cells (pancreatic peptide) 1%  PINEAL GLAND (PINEAL BODY) On the roof of the diencephalon. Covered by pia mater. Conective tissue septa (blood vessels, unmyelinated nerve fibers). Cellular cords 🡪 melatonin. Secrete Melatonin  PINEAL GLAND (PINEAL BODY) STRUCTURE FUNCTION pinealocytes Melatonin secretion: astrocytes ↓ supportgwa15 regulation of seasonal biorythm unmyelinated nerve fibers regulation of circadian biorythm capillaries circadian biorythm Ne5 Pinealocytes - a stre Pinzal ⑦ - Pr - fis astrocy Unmeye  THE MAIN FUNCTION OF THE PINEAL GLAND Melatonin - secretion in the circadian cycle, the biggest releasing of the melatonin is at night. It induces sleepiness and sleep. inhibits the development of the gonads. - - Vasotocin - function is not fully understood. It acts as a anti gonadotropin- I Or Metall Vasstezi. Vaso Thank you Hour Ca - 06.03.2027