The Endocrine System Qian XiaoJing Dept. of Anatomy, Histology & Embryology PUMC pumc_he@126.com 69156461
Symptoms Failure of lactation Breast atrophy Lack of menstrual bleeding Loss of pubic & axillary hair Intolerance to cold Fatigue Low blood sugar levels Hemorrhage & shock during obstetrical delivery
the Endocrine System I. General Features II. Thyroid Gland III. Parathyroid Gland IV. Adrenal Gland V. Pituitary Gland
I. General Features Exocrine gland Endocrine gland
I. General Features Hormones Inclusive nitrogen ~ Steroid ~
1. Ultrastructure of endocrine cells 1) Peptide-secreting cells 2) Steroid-secreting cells
1. Ultrastructure of endocrine cells 1) Peptide-secreting cells rer, Golgi complex membrane-bound vesicles
2) Steroid-secreting cells lipid droplets Mit. (tubular & vesicular cristae) ser
2. Distribution of the endocrine cells dispersed endocrine cells endocrine tissues endocrine glands
3. Characteristics of the endocrine gland ductless glands cells arranged in follicles, cords or clumps highly vascularized fenestrated cap. (sinusoid) delicate C.T. (reticular fiber)
the Endocrine System I. General Features II. Thyroid Gland III. Parathyroid Gland IV. Adrenal Gland V. Pituitary Gland
II. Thyroid Gland 1. Gross structure
2. Microscopic structure capsule, lobules follicles structure / functional unit follicular cells colloid fenestrated capillaries
1) follicle cells (thyrocytes) LM: squamous cuboidal low columnar varies with functional activity
1) follicle cells (thyrocytes) LM: EM: Functions: secrete the thyroid hormones (T 3,T 4 (thyroxine))
Steps in the synthesis & secretion of T 3, T 4 a. synthesis of thyroglobulin rer, Golgi complex b. uptake & activation of iodide iodine (TSH) pump, Mit., membrane-bound peroxidase c. iodination of tyrosine residue of thyroglobulin microvili d. reuptake of colloid (TSH) endocytic vesicles e. digestion of iodinated thyroglobulin lysosome f. release of T 3 & T 4
functions of the thyroid hormone regulation of the body s basal metabolic rate hyperthyroidism ( 甲亢 ) hypothyroidism ( 甲减 )
2) parafollicular cells (C cells) Location: within the follicle basal lamina between the follicle
2) parafollicular cells (C cells) Location: LM: EM: pale staining secretory granules Functions: secrete calcitonin
III. Parathyroid Gland 1. Gross structure
2. Microscopic structure capsule cells arrange in cords capillaries adipocytes HE Triple staining
1) chief (principal) cells LM: small polygonal cells pale cytoplasm centrally located nucleus EM: irregularly shaped granules lipofuscin-containing vesicles Function: parathyroid hormone (PTH)
2) oxyphil cells Location: singly / in cluster LM: large cell acidophilic cytoplasm small dark nucleus EM: mitochondria (abnormally shaped ) Function: unknown
the regulation of calcium balance
the Endocrine System I. General Features II. Thyroid Gland III. Parathyroid Gland IV. Adrenal Gland V. Pituitary Gland
IV. Adrenal Gland 1. Gross structure dense C.T. capsule cortex yellowish medulla reddish-brown
2. Microscopic structure dense C.T. capsule cortex zona glomerulosa ~ 5% zonafasciculata ~75% zona reticularis ~10% medulla
1) cortex (1) zona glomerulosa arranged in rounded or arched cords secrete mineralocorticoid (aldosterone 醛固酮 )
(2) zona fasciculata arranged in long straight cords cells contain many lipid droplets secrete glucocorticoid (cortisol 皮质醇 )
(3) zona reticularis 7% arranged in anastomosing network cells contain lipofuscin secrete androgen ( dehydroepiandrosterone 脱氢表雄酮 )
cortex steroid-secreting zona glomerulosa zona fasciculata zona reticularis Addison's disease
2. Microscopic structure cortex steroid-secreting medulla catecholamine-secreting medullary cells ganglion cells
2) medulla (1) medullary cells LM: large, pale-staining polyhedral cells chromaffin cells, 嗜铬细胞
EM: epinephrine -secreting cells (E) norepinephrine -secreting cells (NE) membrane-bound granule Functions: secrete E/NE
(1) medullary cells modified neurons
(2) ganglion cells
3. Blood supply cortical arterioles medullary arterioles cortical capillary medullary capillary (dual blood supply) central medullary vein
高峰让吉 In 1901 he isolated and purified the hormone adrenaline http://songshuhui.net/archives/85297
the Endocrine System I. General Features II. Thyroid Gland III. Parathyroid Gland IV. Adrenal Gland V. Pituitary Gland
V. Pituitary Gland (Hypophysis) The Master Gland
1. Gross structure neurohypophysis adenohypophysis infundibulum pars nervosa pars intermedia pars distalis pars tuberalis median eminence infundibular stem posterior lobe anterior lobe
2. Embryogenesis neurohypophysis : neural ectoderm (diencephalon) adenohypophysis : oral ectoderm (Rathke s pouch )
Hypothalamo - hypophyseal system neuroendocrine cells
4. Neurohypophysis 1) unmyelinated nerve fibers 2) pituicytes: branched glial cells 3) capillaries 4) Herring bodies (neurosecretory b~) faintly eosinophilic 室旁核视上核 Percy Theodore Herring (1872-1967 ) English physician and physiologist
室旁核 视上核 ADH Oxytocin increases trust in humans Vol 435 2005 nature03701
5. Adenohypophysis 1) pars distalis 2) pars intermedia 3) pars tuberalis
1) pars distalis arranged in cords capillaries cells chromophils acidophils (40%) basophils (10%) chromophobes (50%)
chromophils acidophils basophils somatotropic cells mammotropic cells thyrotropic cells corticotropic cells gonadotropic cells
(1) somatotropic cells (50%) acidophils growth hormone (GH) dwarfism, giantism, acromegaly
(2) mammotropic cells (15-20%) acidophils prolactin (PRL)
(3) thyrotropic cells (5%) basophils thyrotropin (TSH) goiter, hypothyroidism
(4) corticotropic cells (15-20%) basophils adrenal corticotropin (ACTH), -lipotrophin ( - LPH) (POMC) 阿黑皮素原 Addison's disease
(5) gonadotropic cells (10%) basophils follicle stimulating hormone (FSH) luteinizing hormone (LH) amenorrhea, infertility
acidophils somatotropic cells chromophils (40%) mammotropic cells thyrotropic cells chromophobes (50%) basophils (10%) corticotropic cells gonadotropic cells tropic hormone
(6) chromophobes degranulated chromophils undifferentiated cells supporting cells
4. Adenohypophysis 1) pars distalis 2) pars intermedia 3) pars tuberalis
2) pars intermedia follicles & cords chromophobes & basophils (melanocyte stimulating hormone, MSH)
3) pars tuberalis cell arranged in cords chromophobes, basophils: gonadotrophs abundant longitudinal blood vessels
4) blood supply superior hypophyseal a. hypophyseal portal system primary capillary plexus (infundibulum) portal veins (pars tuberalis) secondary capillary plexus (pars distalis) hypophyseal veins
4) blood supply inferior hypophyseal a. capillaries hypophyseal veins
5) the hypothalamus & adenohypophysis negative feedback neuroendocrine cells in hypothalamic nuclei (RH, IH) the portal system the endocrine cells in pars distalis target cells hypothalamusadenohypophysistarget gland axis RH: releasing hormone, IH: inhibiting hormone
Pituitary Gland The Master Gland hypothalamo - hypophyseal tract hypothalamo - hypophyseal portal system
Sheehan's syndrome (Postpartum hypopituitarism) 产后垂体功能减退 Symptoms may include: Failure of lactation Breast atrophy Lack of menstrual bleeding Loss of pubic & axillary hair Low blood sugar levels Intolerance to cold Fatigue Hemorrhage & shock during obstetrical delivery
summary the Endocrine System I. General Features II. Thyroid Gland III. Parathyroid Gland IV. Adrenal Gland V. Pituitary Gland
Peptide-secreting cells rer, Golgi complex membrane-bound vesicles Steroid-secreting cells lipid droplets Mit. (tubular & vesicular cristae) ser
Characteristics of the endocrine gland ductless glands cells arranged in follicles, cords or clumps highly vascularized fenestrated cap. (sinusoid) delicate C.T.
Thyroid Gland Steps in the synthesis & secretion of T 3, T 4 thyroid follicles follicle cells secrete the thyroid hormone parafollicular cells secrete calcitonin
Parathyroid Gland chief cells secrete parathyroid hormone oxyphil cells
Adrenal Gland
Pituitary Gland structure
hypothalamus and hypophysis hypophyseal portal system