4.01 Remember the structures of the urinary system

1. 4.01 Remember the structures of the urinary system

2. 4.01 Remember the structures of the urinary systemEssential Question What are the structures of the urinary system? 4.01 Remember the structures of the urinary system

3. Functions of the Urinary System • Excretion- removing nitrogenous wastes, certain salts and excess water from blood. • Maintain acid-base balance • Secrete waste products in the form of urine • Eliminate urine from bladder 4.01 Remember the structures of the urinary system

4. Structures of the urinary system • Kidneys • Ureters • Bladder • Urethra • Urinary meatus 4.01 Remember the structures of the urinary system

5. Structures of the urinary system Kidneys • Most important excretory organ • Bean-shaped • Located between peritoneum and the back muscles (retroperitoneal) • Held in position by connective tissue • Enclosed in an adipose capsule • Protected by the ribs 4.01 Remember the structures of the urinary system

6. Structures of the urinary system Kidneys • External structures • Renal capsule • Renal hilum • Internal structures • Renal cortex • Renal medulla • Renal pelvis 4.01 Remember the structures of the urinary system

7. Structures of the urinary system External kidney • Renal fascia • Fibrous layer of connective tissue • Renal hilum • Indentation that gives the kidney its bean-shaped appearance 4.01 Remember the structures of the urinary system

8. Structures of the urinary system Internal kidney • Renal cortex • Outer layer • Renal medulla • Middle layer • Renal pelvis • Innermost layer 4.01 Remember the structures of the urinary system

9. Structures of the urinary system Renal cortex • Composed of millions of microscopic functional units called nephrons 4.01 Remember the structures of the urinary system

10. Structures of the urinary system Nephron • Functional unit of kidney • Renal corpuscle • Bowman’s capsule • Glomerulus • Renal tubule • Proximal convoluted tubule • Loop of Henle • Distal convoluted tubule • Collecting tubules Each kidney contains about 1.3 MILLION nephrons! 4.01 Remember the structures of the urinary system

11. Structures of the Urinary system Renal medulla • Inner, striated layer • RENAL PYRAMIDS are the striated cones. • Base of each pyramid faces cortex, while apex empties into cuplike cavities called CALYCES • Renal columns • Located between the pyramids • Cortical tissue 4.01 Remember the structures of the urinary system

12. Structures of the urinary system Renal pelvis • Funnel shaped structure at the beginning of the ureter 4.01 Remember the structures of the urinary system

13. Structures of the urinary system Ureters • Muscular tube extending from each kidney to the urinary bladder • Lined by a mucous membrane • 10-12” long Ureters 4.01 Remember the structures of the urinary system

14. Structures of the urinary system Urinary bladder • Hollow muscular organ • Located in pelvic cavity • Made of elastic fibers and involuntary muscles 4.01 Remember the structures of the urinary system

15. Structures of the urinary system Urethra • Connects the bladder to the outside of the body • Female 1-2” long • Male 4-6” long Urinary meatus • Opening to the outside of the body Female Male 4.01 Remember the structures of the urinary system

16. Urine Formation in the Nephron 4.01 Remember the structures of the urinary system

17. Filtration • First step in urine formation • Blood from renal artery enters glomerulus • High Blood pressure in glomerulus forces fluid (filtrate) to filter into Bowman’s capsule • Filtrate does not contain plasma proteins or RBC’s they’re too big • Bowman’s capsule filters out 125cc of fluid/min- 750cc/hr • As filtrate continues through nephron, 90% of water is reabsorbed 4.01 Remember the structures of the urinary system

18. Reabsorption • Water and useful substances are reabsorbed • If blood levels of certain substances are high ( glucose, amino acids, vitamins, sodium) then those substances will not be reabsorbed 4.01 Remember the structures of the urinary system

19. Secretion • Opposite of reabsorption • Secretion transports substances from blood into collecting tubules • Substances include creatinine, hydrogen ions, potassium ions, and some drugs • Electrolytes are selectively secreted to maintain body’s acid-base balance. 4.01 Remember the structures of the urinary system

20. Urinary Output • Average=1500ml/day • Urinalysis – examination of urine to determine presence of blood cells, bacteria, acidity level, specific gravity and physical characteristics (color, clarity, and odor) 4.01 Remember the structures of the urinary system

21. Control of Urinary Secretion • Chemical Control • Reabsorption of H2O indistal convoluted tubule controlled by ADH (antidiuretic hormone) • Secetion and regulation of ADH controlled by hypothalamus • DIURETICS inhibit reabsporption of H2O • Nervous Control • Direct control through nerve impulses on kidney blood vessels • Indirect control through stimulation of endocrine glands 4.01 Remember the structures of the urinary system

22. Fluid and electrolyte balance • Electrolytes are selectively secreted to maintain body’s acid-base balance. • What are electrolytes? "medical/scientific" term for salts, specifically ions. • What do they do Electrolytes are important because they are what your cells (especially nerve, heart, muscle) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells • What is the relevance to health? 4.01 Remember the structures of the urinary system

23. 4.01 Remember the structures of the urinary systemEssential Question What are the structures of the urinary system? 4.01 Remember the structures of the urinary system