1. URINARY SYSTEM

3. Overall Function Blood homeostasis Excretes waste Regulates blood pressure Erythropoeisis Activates Vitamin D

4. Kidneys Renal, Nephr- T12-L3 region Retroperitoneal Protective layers – Renal capsule – Adipose capsule – Renal fascia

6. Kidney Hilus Cortex Medulla – Renal pyramids (8-18) – Renal papilla Pelvis – Minor calyx – Major calyx

9. Kidney Microstructure Nephron Functional unit of the kidney Glomerulus Network of blood capillaries Afferent & Efferent arterioles Slits & Pores

11. Nephron - Tubules Glomerular capsule (Bowman’s capsule) – Renal corpuscle Proximal convoluted tubule Descending limb of loop of nephron (Henle) Loop of nephron Ascending limb of loop of nephron Distal convoluted tubule Collecting tubule

14. Blood supply 1200 ml/min Filters blood volume 60 x/day 1/5 CO

16. Nephron Physiology Controls blood concentration & volume Helps regulate blood pH Removes toxic waste from blood Urine production (2-4 pts/day)

17. Glomerular filtration 45 gallons of filtrate/day! Passive process Glomerulus to capsule

20. Glomerular filtration Net filtration pressure favors filtration Glomerular blood pressure (60 mm Hg, other caps are 10-30 mm Hg) Capsular pressure – Opposes filtration Colloid osmotic pressure – Opposes filtration

25. Arterial blood pressure Stable glomerular filtration rate Urine output increases/decreases as blood pressure increases/decreases

26. Sympathetic stimulation

27. Tubular Reabsorption & Secretion Proximal convoluted tubule Permeable to solutes & they are actively reabsorbed Permeable to water & it is passively reabsorbed Some tubular secretion (H+ and K+)

31. Descending limb Relatively impermeable to solutes Permeable to water, it is reabsorbed Interstitial gradient promotes reabsorption

33. Loop Urea is recycled

35. Ascending limb Permeable to NaCl, it is reabsorbed Impermeable to water

38. Distal Convoluted Tubule Aldosterone Anti-diuretic hormone Secretion occurs (H+, NH3, drugs) Juxtaglomerular apparatus (where precursors of erythropoeitin & renin are made)

40. Collecting tubule (ducts) Aldosterone causes sodium reabsorption ADH causes water reabsorption Urea to interstitial space

42. Vasa recta Thin walled blood vessels serving tubules Counter-current Maintains interstitial concentrations Aids in concentrating urine Some water reabsorption

49. Other renal functions Vitamin D activations Erythropoietin precursor Blood pressure - renin

50. Minimum urine volume.5 liters/day Maximum urine concentration is 1200 milliosmoles/liter Make about 600 mosmol of waste/day 600 mosmol waste/day / 1200 mosmol/liter =.5 liters/day

51. Ureter Kidney to bladder Peristalsis

53. Urinary Bladder Holds up to about 800 mls of urine in pelvic cavity Internal & External sphincters Micturition = Urination Micturition reflex Voluntary urination

58. Urethra Urinary bladder to external urethral orifice Long in males, short in females