Urinary System - Mod. 3 Flashcards
What percentage of urine is water? and what substances make up remaining percent of urine?
95% water, 5% are products of metabolism, urea, ammonia, bilirubin, and uric acid.
What ions does the urinary system regulate in the blood?
Sodium, potassium, calcium, chloride, and phosphate ions.
How do the kidneys maintain blood osmolarity?
Regulating the total number of particles dissolved per liter of solution.
How does the urinary system regulate blood pH?
Excreting hydrogen ions and altering the concentration of bicarbonate ions.
How does the urinary system regulate blood pressure?
Through the secretion of renin, increase in renin concentration raises blood pressure.
What hormones are produced by the kidneys?
renin, erythropoietin, and calcitriol.
What is the function of renin?
Regulates blood pressure.
What is the function of erythropoietin?
Stimulates the production of red blood cells.
What is the function of calcitriol?
Enhances the absorption of calcium and phosphorus from food, and increases the amount circulating in the blood.
How does the urinary system regulate blood glucose?
When blood glucose levels fall, the kidneys metabolize glutamine to synthesize new glucose molecules, via gluconeogenesis, causing the blood glucose levels to rise.
What is the shape, color, and length of the kidneys?
Bean shaped, reddish-brown in color, and about 11cm long.
What is the function of the hilum in the kidneys?
The hilum is the entry and exit point for the renal vessels and the renal pelvis.
Where do the renal arteries arise from?
Directly from the abdominal aorta, suppyling the kidneys.
What do most renal nerves regulate?
The volume of blood flowing through the kidneys by affecting the vasoconstriction or vasodilation of the arterioles.
What nervous system are the renal nerves apart of?
The autonomic nervous system.
What are the functional units of urinary system?
Nephrons
What does the renal corpuscle contain?
It contains a compact network of capillaries, called glomerules, which is surrounded by the glomerular capsule (bowmans capsule)
What is the function of nephrons?
Filter the blood to produce urine, removing waste or unwanted substances from the body, while retaining nutrients and other important substances.
What are the two types of nephrons?
85% are cortical nephrons, and the other 15% are juxtamedullary type.
What are the two major portions of nephrons?
Renal tubule and renal corpuscle.
Where does glomerular filtration occur?
In the renal corpuscle, when blood in the glomerulus is under pressure.
What happens during glomerular filtration?
The blood if filtered, and water and solutes move out, forming a fluid called glomerular filtrate (tubular fluid)
What is tubular reabsorption?
Water and solutes are reabsorbed from the tubular fluid and move back into the blood.
What percent of water filtered into the glomerular capsule is reabsorbed into the bloodstream?
Approximately 99%