1 / 14

Endocrine Organs

Endocrine Organs. Intercellular communication : nervous system : neurotransmitters endocrine system : hormones : Hormone : steroids : small peptides, proteins, glycoproteins : amino acid analogues and derivatives :. Hypophysis. Adenohypophysis : pars distalis : pars intermedia :

kennan-riddle
Download Presentation

Endocrine Organs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Endocrine Organs • Intercellular communication : • nervous system : neurotransmitters • endocrine system : hormones : • Hormone : • steroids : • small peptides, proteins, glycoproteins : • amino acid analogues and derivatives :

  2. Hypophysis • Adenohypophysis : • pars distalis : • pars intermedia : • pars tuberalis : • Neurohypophysis : • pars nervosa : • infundibulum :

  3. Blood Supply • Blood supply : • superior hypophyseal arteries : • pars tuberalis, median eminence, infundibular stem • inferior hypophyseal arteries : • pars nervosa • hypophyseal portal System : anterior lobe • primary capillary plexus • secondary capillary plexus :

  4. Adenohypophysis • Tropic homones : • regulate activity in other endocrine glands • Stain reaction : • basophils : 10% • acidophils : 40% • chromophobes : 50% • Hormones : • small proteins or glycoproteins

  5. Hormones • Andenocorticolipotropes : • adrenocorticotropic hormone (ACTH), lipotropic hormone (LPH) • Gonadotropes : • luteinizing hormone (LH), follicle-stimulating hormone (FSH) • Thyrotropes : thyroid-stimulating hormone (TSH) • Somatotropes : somatotropin • Lactotropes : prolactin (PR) or lactogenic hormone (LTH)

  6. Neurohypophysis • Neurosecretory neuron : • supraoptic nuclei : • parventricular nuclei : • Storage site of neurosecretion : • secretory granules Herring bodies • Hormones : • vasopressin (antidiuretic hormone) (ADH) • oxytocin • neurophysin : hormone-binding protein

  7. Hormone and Pituicyte • ADH : • secretory neucrons : serve as osmoreceptors • increase permeability of distal portion of nephron • disease : diabetes insipidus • Oxytocin : • smooth muscle contraction : • uterine : copulation and parturition • myoepithelial cells : breast • Pituicyte : astrocyte

  8. Hypothalamus and Pineal Gland • Hypothalamus : • regulate function : • promote or inhibit secretion of adenohypophysis hormone • ADH and oxytocin production • Pineal gland : • melatonin : inhibiting steroidogenic activity of gonads • cell : • pinealocytes, interstitial (glial) cell • corpora arenacea (brain sand)

  9. Thyroid Gland • Follicle : • follicular (principal) cell : secrete T3,T4 • secretory and absorptive cell : colloidal resorptive droplets • thyroid hormone : stimulate metabolism • colloid : gel-like mass • thyroglobulin (inactive storage form) • parafollicular cell : secrete calcitonin • calcitonin : descrease blood calcium level by suppress bone resorption and increase osteoid calcification

  10. Parathyroid Glands • Embryology : third branchial pouch • Cell consist : • principal (chief) cells : secrete PTH • oxyphils cell : • Parathyroid hormone (PTH) : • function : increase blood calcium level : • stimulate bone resorption : • reduce kidney excretion of calcium : • increase intestinal absorption of calium :

  11. Adrenal Glands • Regional organization • Cortex : steroid-secreting portion • medulla : catecholamine-secreting portion • Blood supply : • capsular capillaries : • fenestrated cortical sinusoidal capillaries : • medullary arterioles :

  12. Zonation of Adrenal Cortex • Zona glomerulosa : • mineralocorticoids : aldosterone (renin-angiotensin system) • Zona fasciculata : • glucocorticoids : hydrocortisone (cortisol) • gluconeogenesis and glycogenesis • feedback control : hypothalamic-hypophyseal CRF-ACTH system • Zona Reticularis : • weak androgens : dehydroepiandrosterone (DHA) • glucocorticoids : hydrocortisone (cortisol)

  13. Adrenal Medulla • Chromaffin cell : modified neurons • norepinephrine population : large dense core granule • epinephrine population : small, less dense granule • glucocorticoid induce the conversion norepinephrine to epinephrine in medullary cells • catecholamine : fight-flight response • stimulate glycogenolysis • mobilization of free fatty acids from adipose tissues • rise blood pressure, cardiac output, increase breathing

  14. Fetal Adrenal Gland • Outer permanent cortex : • thin • Inner fetal zone : • thick • disappearance after birth • Lack a definitive medulla : • Under CRF-ACTH feedback system : • Part of fetal-placental unit :

More Related