Endocrine System

1. Endocrine System

2. exocrine endocrine Endocrine organ No ducts Exocrine organ ducts acini follicle, cord, net like arranged cells Glandular epi.

3. Ways of Secretion

4. Glands can be one of three types Exocrine – release secretions that are carried within a duct or tube – sweat glands, salivary glands, sebaceous glands Endocrine – release secretions directly into the blood – thyroid gland, adrenal gland, anterior pituitary gland Heterocrine – contain both exocrine and endocrine components – pancreas, testis

5. Steroid-secreting cells SER; lipid droplet; mitochrondria Nitrogen-secreting cell RER; Golgi complex; secreting granules;

6. Thyroid Gland Follicular cell follicles C: parafollicular cell

7. Found at 2nd through 4th cartilages of the trachea • Small gland with four parathyroid glands attached to the posterior surface. • Follicles are the structural unit of the gland. • Follicle consists of a wall of simple cuboidal epithelium cells inclosing a space containing a jelly-like substance called colloid. If the colloid distends the follicles, the epithelial cells can become flattened almost like simple squamous. Colloid combines with iodine to form thyroid hormones – regulate body metabolism.

8. Follicles(simple cuboid/culumnar epi.) + fenestrated capillary Follicular cell + basal lamina Follicular cell: T3, T4 Parafollicular cell: calcitonin Follicular cell

9. Between the follicles are located small groups of parafollicular cells which secrete hormone thyrocalcitonin or often called just calcitonin. Calcitonin functions to reduce calcium levels in the blood by actively reducing breakdown of bone and inhibiting re-absorption of calcium in digestive system.

10. parafollicular cell

11. Hyperthyroid condition often result of tumor. Can produce disease called Graves syndrome Hypothyroid condition – cretinism in children and myxedema in adults Thyroid Gland Abnormalities Goggle-eyed Girl 15 with Cretinism myxedema

12. 肾上腺Adrenal gland Cord or net like arranged endocrine cells Blue one: capillary net Zona: encircling beltlike structure

13. Capsule, cortex, medulla Cortex: ZG + ZF + ZR+ capillary Medulla: chromaffin cells + ganglion cell + central vein + capillary

14. Zona reticularis Zona glomerulosa Cortex of adrenal gland

15. Adrenal Cortex consists of three regions: • Outer region known as the zona glomerulosa. Theses cells are arranged in rounded clumps and secrete hormones known as mineralcorticoids. • The most common mineralcorticoid is aldosterone which helps to control electrolyte and water balance. • The next region is known as the zona fasciculata. It consists of columns of cells. It secretes hormone known as glucocorticoids including cortisone and hydrocortisone. • These hormones help to regulate glucose metabolism and important in inflammation reactions and stress management. • The inner region of the cortex is the zona reticularis. Cells of this region form and network of interlinking cells. • Secrete sex hormones mainly androgens or male sex hormones. Usually in small proportions if too many can cause bearded lady.

16. Medulla: chromaffin cells + ganglion cell + central vein + capillary Chromaffin cell: epinephrine cell, norepinephrine cell Central vein

17. The cells of the adrenal medulla can be considered modified sympathetic postganglionic neurons that have become secretory cells.

19. Hormones and functions of adrenal gland

20. Function of adrenal gland

21. Medical applications Iodine deficiency goiter Cushing syndrome

22. Pituitary gland: half for endocrine, another half is the extending of hypothalamus

23. Development of pituitary gland

24. hypothalamus RHs and IHs blood Hypothalamo- putitary portal system hormone putuitary 垂体 Pituitary gland Nervous part Glandular part

25. 下丘脑和垂体 -- 最高司令官

27. Pituitary or Hypophysis • Small gland about size of large pea located under brain. • Often referred to as the “master gland”. • Secretes hormones that regulate other endocrine glands • Consists of two major lobes, anterior and posterior separated by intermediate lobe. • The larger anterior lobe referred to as the adenohypophysis. This is a highly glandular tissue that produces and secretes numerous hormones. • The second smaller posterior lobe is referred to as the neurohypophysis. This is neural tissue that secretes two hormones produced by hypothalmus.

28. The pars distalis :75% of the mass of the hypophysis. Three cell types : + sinusoid chromophobes (Gr. chroma,color, + phobos,fear) two types of chromophils (Gr. chroma+ philein,to love) called basophils and acidophils .

29. Adenohypophysis • Cell types in the adenohypophysis are identified as to their staining characteristics • Chromophilic cells include the acidophils which stain with eosin stain and are thus reddish and the basophils which stain with hematoxylin and are thus dark blue/purple colored in hematoxylin/eosin staining. • Chromophobes do not stain with either stain • There are different types of Acidophils that can be separated with very special stains. These can not be separated with H & E stains. They include: • Somatrophs – secrete Growth Hormone • Mammotrophs – secrete prolactin • There are different types of Basophils that can be separated with very special stains. These can not be separated with H & E stains. They include: • Thyrotrophs – secrete Thyroid Stimulating Hormone • Gonadotrophs – secrete Luteinizing (LH) hormone and Follicle Stimulating Hormone (FSH). • ACTH-secrete adenocorticotrophic hormone regulates adrenal cortex • Chromophobes lactation period

31. Posterior lobe or Neurohypophysis • Consists mostly of nervous tissue, pituitary cell, herring body • Does not produce any hormones but does secrete two hormones produced by the hypothalamus • Secretes oxytocin – regulates uterine muscle contraction and mammory glands stimulating milk flow • Secretes ADH – Antidiuretic hormone which increases water retention by the kidney

32. The neurosecretions are transported along the axons and accumulate at their endings in the pars nervosa. Here they form 下丘脑与神经垂体为一体 structures known as Herring bodies.

33. Pituitary-related disease Hormone hypersecretion hyposecretion GH gigantism dwarf（children） acromegaly ACTH TSH Cushing syndrome Hyperthyroid condition No catamenia --- cretinism prolactin FSH More mammary gland Reproductive system LH

34. 1. Secretion, chemical modification and storage, reuptake, and digestion of a protein occur in epithelial cells of what endocrine tissue? a. Neurohypophysis b. Adrenal medulla c. Adenohypophysis d. Thyroid gland e. Neuroendocrine cells in the duodenum 2. Pregnant women who have begun labor but in whom this process is no longer progressing are often given an IV injection of Pitocin to stimulate uterine contractions and facilitate parturition. Pitocin is a trade name of a hormone produced in what endocrine tissue? a. Pars distalis b. Ovarian follicles c. Pars nervosa d. Placenta e. Pars tuberalis 3. Which of the following accurately describes glucocorticoids? a. Include the steroid hormone aldosterone b. Are produced in response to stimulation by ACTH c. Are produced primarily by the zone glomerulosa d. Typically enhance the immune response e. Include the steroid hormone DHEA

35. 生殖系统 (Reproductive System)

36. 精原细胞/初级精母细胞/次级精母细胞/精子细胞/精子精原细胞/初级精母细胞/次级精母细胞/精子细胞/精子 生殖细胞的分化

37. 卵子发生 精子发生

39. 精子发生 有丝分裂 减数分裂 精原细胞/初级精母细胞/次级精母细胞/精子细胞/精子

40. Testes are contained within the scrotal sac or scrotum and is literally outside body. Within scrotum, the testis (singular) testes (plural) is covered with the layers forming the capsule. the layer is called the tunica albuginea is composed of dense collagenous fibrous tissue. The tunica albuginea thickens and protrudes into the testis to form the mediastinum testis. Septa extend from this to divide the testis into lobules Testes

41. Low magnification of testis showing many seminiferous tubules tortuous

42. Proliferating spermatogenic cells are active and produce spermatozoa by spermatogenesis. Spermatogenic supporting cells called Sertoli or sustentacular cells Testes

43. Germinal or seminiferous epi. Sertoli cell Basement menbrane Myoid cells Blood- testis barrier seminiferous tubules

44. seminiferous tubules HE staining

45. 200000000个精子/天 250-1000个/睾丸 150微米直径 精子发生 spermatogenesis 精子形成 spermiogenesis 30-70厘米长 250米长/睾丸

46. Germ cells comprise a stratified layer of epithelium 4-8 cells deep lining the seminiferous tubule. As these cells differentiate, they move from the basal area toward the lumen of the seminiferous tubule. This process of differentiation is called spermatogenesis and takes about 64 days. The beginning cells are called spermatogia that are found next to the basal lamina. These cells are diploid and are found in the testis prior to puberty. Spermatogenesis

47. Primary spermatocytes are located some distance away from the basal lamina They are much larger and at this point are still diploid cells They divide by meiosis to produce haploid secondary spermatocytes. Although the nuclear division is complete, the cytoplasm remains connected. Secondary spermatocytes division results in the formation of 4 spermatids which are usually still attached by cytoplasm division that is incomplete. Spermatids lie close to the lumen. Spermatids then differentiate forming head region and flagellum to form spermatozoa.(tadpole)(spermiogenesis) mitosis

48. spermiogenesis Spermiogenesis is a complex process that includes formation of the acrosome (Gr. akron, extremity, + soma, body), condensation and elongation of the nucleus, development of the flagellum, and loss of much of the cytoplasm.

49. 精子spermatoza 形似蝌蚪

50. 受精 fertilization