1. Kidney Regulation

2. ADH Antidiuretic hormone Regulate reabsorption by kidneys
Diuretic: promotes production of urine
Regulate reabsorption by kidneys
Osmoreceptors in hypothalamus
Stored in pituitary gland
Thirsty
Ethanol
Osmoreceptor nerve cells in hypothalamus shrink when low water concentration and high solute concentration in bloodstream
Shrinking of osmoreceptors cause sensation of thirst
Sends signal to pituitary to release ADH
ADH causes kidneys to reabsorb more water
Distal convoluted tubule and collecting duct permeable to water
Water drawn from nephron via osmosis
Ethanol is a diuretic
Causes more formation of urine
Less reabsorption of solutes
Can cause dehydration

3. Blood Pressure
Decrease in blood pressure detected by juxtaglomerular apparatus
Low blood pressure = reduced O2
Renin released by JGA
Converts angiotensinogen to angiotensin
Angiotensin
Constriction of blood vessels
Stimulates release of aldosterone to increase Na+ transport

5. pH Balance Normal blood pH: 7.35 – 7.45 H+ and HCO3+
Regulate blood pH by the active transport of H+ ions into the filtrate
Buffer system
CO2 actively transported out of peritubular capillaries
CO2 combines with water to form HCO3- or H+
Secretion of H+ ions either slows or increases until the pH returns to normal
Excess H+ buffered by bicarbonate ions
Urine pH is between 4.5 and 8.0

6. Kidney Disease Diabetes Mellitus Diabetes Insipidus
Type 1 or type 2
Inadequate secretion of insulin from the pancreas results in excess sugar being excreted in the urine
Causes excess water loss; constant thirst
Diabetes Insipidus
Destruction of ADH producing cells in the hypothalamus or the nerve tract to the pituitary gland
Large urine output
Bright’s Disease (Nephritis)
Inflammation of the nephrons
Toxins alter the permeability of the nephrons
Kidney Stones
Precipitation of mineral solutes from the blood
Lodge in the renal pelvis and cause pain as they move to the urethra

7. Homework
Have a safe and relaxing Christmas Break!