excretory system exam study

• What is the primary function of the excretory system?

  To regulate the chemical composition of body fluids
• How does the excretory system maintain body fluid composition?

  By removing metabolic wastes and retaining proper amounts of water, salts, and nutrients
• Which organs are components of the excretory system?

  The kidneys, liver, lungs, and skin
• What process occurs in the liver related to amino acids?

  Deamination of amino acids produces urea
• Where is urea transported after its production?

  To the kidneys for removal
• What are the three basic processes facilitated by nephrons in the kidney?

  Filtration, reabsorption, and secretion

  
• Is hormone control required for the processes in nephrons?

  No, hormone control is not required
• What are the five homeostatic functions of the urinary system?

  1. Regulate blood volume and blood pressure
  2. Conserve valuable nutrients
  3. Remove metabolic wastes
  4. Maintain electrolyte balance
  5. Regulate acid-base balance
• What percentage of water are infants composed of?

  73% or more
• How does total water content change throughout life?

  Total water content declines throughout life
• What is the approximate water content percentage for healthy males and females?

  Healthy males are about 60% water; healthy females are around 50%
• What are the two main fluid compartments in the body?

  Intracellular fluid (ICF) and extracellular fluid (ECF)
• What is the primary role of water in the body?

  Water is the universal solvent
• How are solutes classified in body fluids?

  Solutes are broadly classified into extracellular and intracellular fluids
• What is the quantity of Na+ in extracellular fluid?

  145 milliequivalents per litre
• What is the quantity of K- in intracellular fluid?

  120 milliequivalents per litre
• How much blood flows through the liver every minute?

  1450 cm³ of blood
• What are the functions of the liver?

  1. Converts amino acids to glucose (gluconeogenesis)
  2. Metabolizes fat (produces lipids from excess glucose)
  3. Synthesizes triglycerides (from breakdown of lipids)
  4. Synthesizes and regulates cholesterol
  5. Deamination and transamination
  6. Produces bile (from breakdown of hemoglobin)
  7. Detoxification (e.g., metabolizing alcohol)
• What happens to excess dietary amino acids?

  They are removed through deamination
• What is produced when the amine group is removed during deamination?

  Ammonia (NH₃) is produced
• What happens to ammonia after it is produced?

  It is combined with CO₂ to produce urea
• What are the two important tissues that make up the kidneys?

  Blood vessels and tubules

  
• What are the three stages of kidney function?

  1. Ultrafiltration: Water and products of digestion are squeezed into tubules
  2. Waste removal: Excess water, ions, and urea are removed through the ureter
  3. Selective reabsorption: Blood reabsorbs needed substances like glucose and ions
• What is the role of aldosterone in urine production?

  Aldosterone increases Na⁺ and K⁺ levels in the blood
• How does antidiuretic hormone (ADH) affect urine production?

  ADH makes the distal convoluted tubules and collecting duct more permeable to water

  
• What controls the amount of water reabsorbed in the kidneys?

  The hormone ADH controls the amount of water reabsorbed