UNIT 10 The Urinary System Part 1 of 2 Chapter 25

1. UNIT 10 The Urinary System Part 1 of 2 (Chapter 25) Overview of the Urinary System Kidneys (Gross and Microscopic Anatomy) (7th edition)

2. Overview of the Urinary System (fig. 25.1) Major Organs kidneys - have many functions, including the formation of urine ureters - transport urine from the kidneys to the urinary bladder urinary bladder - stores urine urethra - exit for urine to leave body (7th edition)

3. Overview of the Urinary System (fig. 25.1) Major Functions (of the kidneys) regulation of extracellular fluid (ECF) volume - extracellular fluid volume and blood pressure are closely linked; when ECF volume decreases, blood pressure decreases; when ECF volume increases, blood pressure increases regulation of osmolarity - mechanisms, such as thirst, help to maintain blood osmolarity (=number of ions or molecules per liter of solution, or solute concentration) maintenance of ion balance - key ions (e.g. Na+, K+, and Ca++) are kept within a normal range by balancing dietary intake and loss through urine homeostatic regulation of pH - if ECF becomes too acidic, the kidneys remove H+ and conserve bicarbonate ions (HCO3-); likewise, when ECF becomes to alkaline (basic), the kidneys remove bicarbonate ions (HCO3-) and conserve H+; recall that the lungs also correct pH disturbances through the regulation of carbon dioxide in the blood; regulation by the kidneys is a much slower process excretion of waste and foreign substances - removal of metabolic wastes (e.g. creatinine, urea, and uric acid), drugs, and environmental toxins from the body production of hormones and enzymes - synthesis of the hormone erythropoietin for the regulation of red blood cell synthesis; also secretion of the enzyme renin for the regulation of hormones involved in sodium balance and blood pressure homeostasis (7th edition)