Urinary System Flashcards
Kidney functions:
• removal of waste
• water balance
• salt balance
• blood pressure homeostasis
• acid/base balance of blood
How are the kidneys held in place
By fat
Where are the kidneys
Retroperitoneal (back of the abdomen, behind the peritoneum)
Kidneys bear the major responsibility of:
Eliminating nitrogenous wastes, toxins and drugs
The kidneys filter gallons of?
Fluid from the bloodstream
How does the kidneys regulate blood volume
Maintains proper balance between water and salts, between acids and bases
What do the kidneys produce
• enzyme renin to regulate BP
• hormone erythropoietin to stimulate red blood cell production in bone marrow
The kidney cells convert:
Vitamin D produced in the skin to its active form, calcitriol
How much blood is filtered through the kidneys
One-quarter of the total blood supply every minute
What supplies the kidney with blood
The renal artery
What is the functional unit of the kidney
Nephron
Function of the nephron within the kidneys
• filter that forms urine
What is glomerular filtration
• non-selective, passive process
• fluid passes from the blood to the glomerular capsule & part of the renal tube
• filtrate (blood plasma without blood proteins)
• proteins and blood cells are normally too large to pass through the filtration membrane
• normal systemic BP allows filtrate to form
• low BP = low glomerular pressure and filtrate formation stops.
What is tubular reabsorption
• reclaims useful substances like water, glucose, amino acids, ions and return to blood
• active transport - uses membrane carriers, requires ATP and is selective
• some passive transport of water via osmosis
• mostly occurs in DCT
What is tubular secretion?
• elimination of substances that remain in the blood through peritubular capillary
• additional means for controlling blood pH