Kharkov National Medical University

1. Kharkov National Medical University LECTURE for dentistry students Department of Histology, cytology and embryology

2. The Urinary System • Kidneys II. Ureters III. Bladder IV. Urethra

3. Functions of the urinary system • Excretion • of wastes from body fluids • Regulation of • blood volume and pressure • plasma ion concentrations +Conserving nutrients

4. Structure of the kidneys • Outer cortex and inner medulla • The cortex is composed of 1.25 million nephrons – structural and functional units

5. The Structure of the Kidney Figure 26.4a, b

6. Nephron functions include: • Filtration of blood • Reabsorption of organic nutrients, • water and ions • Secretion of waste products into tubular fluid

7. Nephron consists of: 1. renal corpuscle 2. PCT – proximal convoluted tubule 3. loop of Henle 4. DCT – distal … Collecting tubule receives urine

8. 1. Renal Corpuscle – filtration of blood Consists of: A. Bowman’s capsule with parietal and visceral layers and

9. B. Glomerulus of capillaries Blood is filtrated because of big pressure due to: afferent arteriole brings blood to capillaries is twice bigger, then efferent arteriole, taking blood from capillaries Glomerulus

10. 1. Renal Corpuscle B. Bowman’s capsule 1. visceral layer consists of podocytes with processes

11. 1. Renal Corpuscle Processes interdigitate around glomerular capillaries. The narrow space between processes is the filtration slit.

12. FILTRATION BARRIER: 1. Endothelium of capillary (fenestry) 2. Basal lamina - 3 layers 3. Podocytes (slits) Through barrier pass wastes, water, small proteins, sugar, salts 150 litres of primary urine per day - by filtration 1.5 litres of urine per day - by reabsorption

13. 2. Proximal Convoluted Tubule Reabsorption: simple cuboidal epithelium with brush border longest tube

14. 2. Proximal Convoluted Tubule 1. brush border = microvilli

15. 2. Proximal Convoluted Tubule reabsorption of: a. all glucose b. amino acids c. ~85% NaCl & H20 b. protein secretion/excretion

16. 3. Loop of Henle 1. forming hypertonic urine 2. is almoust impermeable to water

17. 4. Distal Convoluted Tubule 1. simple cuboidal epithelium 2. cells smaller than PCT 3. lack brush border

18. 4. Distal Convoluted Tubule Functions under influence of aldosterone 2. absorbs Na+ (and H2O) 3. secretes K+, H+, NH4++

19. Urine Production • 3 process involved in urine production • All of these processes occur in the Nephrons of the kidneys • Glomerular filtration • Tubular Reabsorption • Tubular excretion and secretion

20. All nephrons enter toCollecting Tubules Under ADH (vasopressin) reabsorps H2O

21. Collecting Tubules continue to calyces and pelvis

22. Juxtaglomerular apparatus a. Juxtaglomerular cells -modified smooth muscle of afferent arteriole synthesize renin effect: increase Na+ and Cl- absorption – distal tubules

23. b. macula densa of DCT - cells columnar, able to sense ionic concentration. c. polkissen cells, additional renin secretion

24. Blood Flow • Renal artery • Interlobar arteries C. Arcuate arteries D. Interlobular arteries

25. Ureter & Bladder A. Ureter 1. mucosa a. transitional epithelium b. lamina propria 2. muscularis a. inner longitudinal b. outer circular 3. adventitia

26. Male reproductive system :

27. Functions: • Reproductive --- production of spermatozoa • Endocrine --- production of male sex hormone(testosterone)

28. Testis Septae – divide on lobules • Lobule contains seminiferous tubules

29. The Convoluted Seminiferous Tubules Consists of two types of cells: • spermatogenic cells • Sertoli cells

30. Sertoli cells • provide mechanical support for the spermatogenic cells • and nutrition

31. Spermatogenic cells • Spermatogonia– • Primary spermatocytes • Secondary spermatocytes • Spermatids • Spermatozoa

32. Spermatogenesis • From spermatogonia (stem cells) by meiosis and spermiogenesis form • spermatozoa

33. The Convoluted Seminiferous Tubules

34. Interstitial tissueLeydig cells • lie in between the convoluted seminiferous tubules, • secrete testosterone

35. epididymis • contains a long, highly coiled ductus • for storage of sperms • continues to the vas deferens

36. the accessory sex glands • - the seminal vesicles the formation of the sperm coagulum and regulation of sperm motility • the prostrate liquefies the semen the bulbourethral glands - secret mucous

37. HORMONAL REGULATION

38. FemaleReproductiveSystem

39. Ovary contains Folliclesfor production of ovum and estrogen Follicular development consists of stages Ovarian follicles

40. follicles: Primordial Primary unilaminar multilaminar -1. estrogen Secondary follicle Tertiary - Graaffian

41. (stroma) (in antrum) -estrogen

42. Ovarian Follicles - oogenesisovulation corpus luteum

43. The Corpus luteum- Yellow body Is formed after ovulation (rupture of follicle) theca interna cells and granulosa cells start accumulate lutein. and begin to produce 2. progesterone

44. The Corpus luteum 1. of menstruation – functions within 14 days after ovulation if the oocyte is not fertilized, then degenerates into a corpus albicans - whitish scar tissue in the ovaries. 2. of pregnancy - functions for 2-3 months after ovulation if fertilization occurs.

45. corpus albicans = degenerative corpus luteum

46. The Oviduct The oviduct functions as a conduit for the oocyte, from the ovaries to the uterus.

47. The Oviduct consists of a mucosa, a muscularis and a serosa. epithelium resting on a lamina propria. The muscularis consists of an inner circular layer and an outer longitudinal layer.

48. The Uterus The walls of the uterus are composed of a mucosal layer, the endometrium, and a fibromuscular layer, the myometrium. The peritoneal surface of the uterus is covered by a serosa - perimetrium.

49. The cyclic change of endometrium is called the menstrual cycle (28 days). It happens under hormons of ovary There are three phases: Menstrual - desquamation phase. Postmenstrual or proliferative phase (or follicular), Premenstrual or secretory phase (or luteal), Only the stratum functionalis of mucosa takes part in the menstrual cycle.