Understanding the Urinary System: Components and Functions

1. The Urinary System

2. Learning Objectives : • Membuat peta konsep sistem ekskresi manusia • Mengidentifikasi komponen yang terlibat dalam sistem ekskresi manusia • Menggambar struktur ginjal • Menjelaskan proses pembentukan urine • Membedah serangga untuk diamati struktur alat ekskresinya • Menggambar struktur alat ekskresi serangga berdasarkan hasil pengamatan

3. Learning Objectives : • To make a concept map of excretory system in human • To identify components are involved in human excretory system • To draw kidney structure • To explain the formation of urine • To operate insect for observation its excretory organs structure • To draw structure of excretory organs based on observation result

4. Function • Remove nitrogenous wastes • Maintain electrolyte, acid-base, and fluid balance of blood • Homeostatic organ • Acts as blood filter • Release hormones: calcitriol & erythropoietin

5. Kidneys as Filters • Diuretic- loose water; coffee, alcohol • Antidiuretic- retain water; ADH • Aldosterone- sodium & water reabsorption, and K+ excretion • GFR= 180 liters (50 gal) of blood/day • 178-179 liters are reabsorbed back into blood • Excrete a protein free filtrate

7. The Urinary System Maintaining Chemical Homeostasis

8. The Urinary System

9. blood filtration tubular reabsorption and secretion General Functioning of the Kidney “refreshed” blood urine

10. Nitrogenous Wastes urea uric acid ammonia

11. kidneys ureters urinary bladder urethra Organs of the Urinary System

12. Human Kidney

13. renal pyramids renal pelvis renal cortex renal capsule ureter renal medulla Kidney Anatomy

14. nephron renal artery renal vein Kidney Anatomy

15. blood filtration tubular reabsorption and secretion Nephron Functioning “refreshed” blood urine

16. glomerulus efferent arteriole Bowman’s capsule afferent arteriole proximal convoluted tubule artery distal convoluted tubule peritubular capillaries vein collecting duct loop of Henle

17. Each kidney contains over 1 million nephrons and thousands of collecting ducts renal cortex renal medulla DCT Glomerulus PCT Collecting duct Loop of Henle

18. efferent arteriole afferent arteriole Bowman’s capsule glomerulus Glomerular Filtration Filters blood; proteins can’t pass through

19. The Human Kidney & Nephron

20. How urine produced ??

21. Composition of Glomerular Filtrate • Water • Small Soluble Organic Molecules • Mineral Ions

22. Proximal Convoluted Tubule Reabsorbs: water, glucose, amino acids, and sodium. • 65% of Na+ is reabsorbed • 65% of H2O is reabsorbed • 90% of filtered bicarbonate (HCO3-) • 50% of Cl- and K+

23. Loop of Henle Creates a gradient of increasing sodium ion concentration towards the end of the loop within the interstitial fluid of the renal pyramid. • 25% Na+ is reabsorbed in the loop • 15% water is reabsorbed in the loop • 40% K is reabsorbed in the loop

24. Distal Convoluted Tubule Under the influence of the hormone aldosterone, reabsorbs sodium and secretes potassium. Also regulates pH by secreting hydrogen ion when pH of the plasma is low. • only 10% of the filtered NaCl and 20% of water remains

25. Collecting Duct Allows for the osmotic reabsorption of water. ADH (antidiuretic hormone)- makes collecting ducts more permeable to water-- produce concentrated urine

26. Urine • Water- 95% • Nitrogenous waste: • urea • uric acid • creatinine • Ions: • sodium • potassium • sulfate • phosphate From the original 1800 g NaCl, only 10 g appears in the urine

27. How the kidney does its job! • Kidney Action • Blood enters Bowman’s capsule through a tiny artery — (the renal artery). • The artery branches to form a glomerulus. • Blood pressure forces some blood plasma and small particles into the surrounding capsule — (this is called the nephric filtrate). • Large particles such as blood cells and proteins remain in capillaries. • The nephric filtrate is pushed out of the capsule and into the proximal tubule . • This is where reabsorption begins.

28. Kidney action (cont) • Only materials needed by the body are returned to bloodstream — for example, 99 % of water, all glucose and amino acids and many salts are reabsorbed. • Osmosis , diffusion, and active transport draw water , glucose , amino acids and ions from filtrate into surrounding cells. • Small villi like projections help in the active transport of glucose out of the filtrate and speed up the reabsorption process. • From here, these components return to the bloodstream.

29. Kidney action (cont) • The filtrate reaches the end of the proximal tubule and the fluid is isotonic with the surrounding cells. • Glucose and amino acids have been removed from the filtrate. • The filtrate then moves to the loop of Henle whose primary function is to remove water from the filtrate by osmosis.

30. Kidney action (cont) • There is in increase in sodium concentration in the cells of the loop of Henle as we move from the area of the cortex to the inner pelvis of the kidney. • This causes water to be drawn from the filtrate. • These high levels of sodium are a result of active transport and results in increased concentration of filtrate (due to water loss).

31. Why doesn’t water on outside go back in? • The water that left the descending loop cannot enter the ascending loop because it is impermeable to water. • As the water concentration in the filtrate decreases, the chlorine concentration increases and causes it to diffuse out of the tubule. • This process is helped by the electrical attraction of chlorine to sodium. .

32. Water (cont) • The filtrate moves to the distal tubule where tubular secretion occurs. • Active transport is used to pull hydrogen ions, creatinine, drugs such as penicillin out of the blood and into the filtrate. • Fluid from a number of nephrons moves from the distal tubules to a common collecting duct which carries what can now be called urine to the renal pelvis.

33. NOTE • Since the kidneys control what leaves and what remains in the nephrons, they maintain the levels of water, ions and other materials nearly constant and within the limits to maintain homeostasis.

35. Elaborate • Exocrine/Endocrine Comparison Research ?????????? • Exocrine/Endocrine System BINGO

36. Hormonal Control of Kidney Function

37. heart receptors hypothalamus Hormonal Control of Kidney Function high plasma solute concentration low blood volume

38. posterior pituitary antidiuretic hormone collecting ducts Hormonal Control of Kidney Function hypothalamus

39. Hormonal Control of Kidney Function

40. juxtaglomerular apparatus renin Hormonal Control of Kidney Function reduced blood pressure and glomerular filtrate

41. angiotensinogen angiotensin I angiotensin II Hormonal Control of Kidney Function renin

42. adrenal cortex aldosterone convoluted tubules Hormonal Control of Kidney Function angiotensin II

43. ureters internal sphincters external sphincters urethra Urinary Bladder

44. Bladder • Mucosa (transitional epithelium) • Muscular layer (detrusor muscle): 3 layers of smooth muscle • Fibrous adventia

45. Sphincter Muscles on Bladder • Internal urethral sphincter: • Smooth muscle • Involuntary control • More superiorly located • External Urethral sphincter: • Skeletal muscle • Voluntary control • Posteriorly located

46. Diuresis (Micturition) When bladder fills with 200 ml of urine, stretch receptors transmit impulses to the CNS and produce a reflex contraction of the bladder (PNS) When is incontinence normal?

47. Distension of the Urinary Bladder

48. Urinalysis Why do doctors ask for a urine sample?        • characteristics: • smell- ammonia-like • pH- 4.5-8, ave 6.0 • specific gravity– more than 1.0; ~1.001-1.003 • color- affected by what we eat: salty foods, vitamins

49. Odor odor- normal is ammonia-like diabetes mellitus- smells fruity or acetone like due to elevated ketone levels diabetes insupidus- yucky asparagus---

50. pH- range 4.5-8 ave 6.0 vegetarian diet- urine is alkaline protein rich and wheat diet- urine is acidic