Lecture 01, 2

• What are the organs of the urinary system?

  Kidneys, ureters, urinary bladder, urethra

  
• What are the major functions of the kidneys?

  Regulate fluid balance, excrete waste, produce hormones
• How does blood flow through the kidneys?

  Blood enters via renal arteries, exits via veins
• What are the major structures of the kidneys?

  Renal corpuscle, renal tubules, renal capillaries

  
• What is the structure and function of the ureters?

  Muscular tubes transporting urine from kidneys
• What is the role of the urinary bladder?

  Stores urine until excretion
• What is the function of the urethra?

  Conducts urine from bladder to outside
• What is the micturition reflex?

  Involuntary contraction of bladder during urination

  
• How is the micturition reflex activated?

  By the parasympathetic nervous system
• What is one function of the kidneys?

  Regulation of fluid electrolyte balance
• What is another function of the kidneys?

  Regulation of acid-base balance
• What do the kidneys excrete?

  Waste products like urea and ammonia
• What hormones do the kidneys produce?

  Erythropoietin and renin
• What is the nephron?

  Functional unit of the kidney
• How many nephrons are in each kidney?

  Over 1,000,000 nephrons
• What are the two components of each nephron?

  Tubular component and vascular component
• What is the role of the juxtamedullary nephron?

  Maintains osmotic gradient in renal medulla
• What are the two types of nephrons?

  Juxtamedullary and cortical nephrons

  
• What is the juxtaglomerulus apparatus (JA)?

  Contact point of distal tubule and arterioles
• What are the components of the juxtaglomerulus apparatus?

  Macula densa and granular cells
• What does the juxtaglomerulus apparatus regulate?

  Blood volume and pressure
• What is the filtration membrane's structure?

  Three layers: endothelium, basement membrane, epithelium
• What is the glomerular filtration rate (GFR)?

  Amount of fluid filtering into Bowman’s capsule
• What is the average GFR value?

  125 mL/min or 180 L/day
• What forces affect glomerular filtration?

  Colloid osmotic and hydrostatic forces

  
• What are the myogenic and tubuloglomerular feedback mechanisms?

  Regulatory mechanisms for GFR control
• How is GFR controlled by the renin-angiotensin-aldosterone system?

  Regulates blood pressure and preserves GFR

  
• What is the role of atrial natriuretic peptide?

  Regulates blood volume and pressure

  
• What are the three basic processes in the nephron?

  Filtration, reabsorption, secretion

  
• What percentage of blood is filtered in the glomerulus?

  20% of blood arriving
• What is the structure of the renal corpuscle?

  Includes glomerulus and Bowman’s capsule

  
• What is glomerular filtration pressure?

  Pressure driving fluid movement in glomerulus

  
• What is the estimated glomerular filtration rate (eGFR)?

  Calculated estimate of GFR using a formula

  
• How is GFR determined using inulin?

  Inulin is filtered but not reabsorbed
• What is creatinine clearance?

  Measurement of creatinine in urine over 24 hours
• What is myogenic feedback?

  Response of smooth muscle to pressure changes

  
• What happens during vasoconstriction in myogenic feedback?

  Increased resistance to flow and decreased GFR

  
• What is tubuloglomerular feedback?

  Regulation of GFR based on tubular flow

  
• What is the significance of the filtration barrier?

  Prevents proteins from entering the filtrate
• What does the filtrate contain?

  Most plasma constituents like glucose and electrolytes