1What are the main functions of the kidneys?
Regulate water volume, ion concentrations, acid-base balance; excrete metabolic wastes, toxins, and drugs; produce erythropoietin and renin; activate vitamin D; perform gluconeogenesis.
2What organs make up the urinary system?
Kidneys, ureters, urinary bladder, and urethra.
3Where are the kidneys located?
Retroperitoneal in the superior lumbar region between T12 and L5.
4What are the three supportive layers surrounding the kidney?
Renal fascia, perirenal fat capsule, and fibrous capsule.
5What are the three internal regions of the kidney?
Renal cortex, renal medulla, and renal pelvis.
6What is the pathway of urine flow from the kidney to the ureter?
Renal pyramid → minor calyx → major calyx → renal pelvis → ureter.
7What is a nephron?
The structural and functional unit of the kidney that forms urine.
8What are the two main parts of a nephron?
Renal corpuscle and renal tubule.
9What happens in the glomerulus?
Filtration of blood plasma to form filtrate.
10What force drives glomerular filtration?
Hydrostatic pressure.
11What is filtrate composed of?
Blood plasma minus proteins.
12What is the normal glomerular filtration rate (GFR)?
120–125 mL per minute.
13What happens in the proximal convoluted tubule (PCT)?
Major reabsorption of nutrients, 65% of Na+ and water, and many ions.
14What happens in the descending limb of the nephron loop?
Water can leave but solutes cannot.
15What happens in the ascending limb of the nephron loop?
Solutes can leave but water cannot.
16What hormones regulate water and ion reabsorption in the DCT and collecting duct?
ADH, aldosterone, atrial natriuretic peptide, and parathyroid hormone.
17What does ADH do?
Increases water reabsorption and concentrates urine.
18What does aldosterone do?
Increases Na+ reabsorption, increases blood pressure, and decreases K+ levels.
19What is secretion in the nephron?
Movement of substances from blood into the filtrate.
20What substances are commonly secreted?
K+, H+, NH4+, creatinine, organic acids and bases.
21What is an electrolyte?
A substance that dissociates into ions in water and conducts electricity.
22What is the major cation in extracellular fluid (ECF)?
Na+.
23What is the major cation in intracellular fluid (ICF)?
K+.
24What is the normal blood pH range?
7.35–7.45.
25What causes respiratory acidosis?
Hypoventilation leading to increased CO2.
26What causes respiratory alkalosis?
Hyperventilation leading to decreased CO2.
27What are the three chemical buffer systems?
Bicarbonate, phosphate, and protein buffer systems.
28What is chronic renal disease?
GFR less than 60 mL/min for three months.
29What is renal failure?
GFR less than 15 mL/min.
30What are kidney stones made of?
Crystallized calcium, magnesium, or uric acid salts.
31What are the three events in micturition?
Contraction of detrusor muscle, opening of internal urethral sphincter, opening of external urethral sphincter.