renal system Flashcards
What is essential for life?
Water
What happens if water is not conserved and replenished in the body?
Cells would shrivel and die as extracellular fluid would not be maintained
What must be maintained at appropriate concentrations in extracellular fluid?
Salt and water
What accumulates in extracellular fluid that must be removed?
Waste products from metabolism
What is the main nitrogenous waste produced by the body?
Ammonia
How is ammonia converted in the liver?
Ammonia is converted to urea, which is less toxic
What role do the kidneys play in excretion?
Filter urea out of the blood and excrete it in urine
What are the products of protein metabolism during digestion?
Amino acids
What is the process that converts ammonia and CO2 into urea and water?
Ammonia + CO2 –> urea + water
What are the primary functions of the renal system?
- Maintains water balance
- Filters wastes from the blood
- Retains nutrients
- Regulates blood pressure
What is the primary function of the urinary system?
Stores and excretes urine
What role does the urinary system play in blood pH?
Maintains blood pH
What part of the kidney contains the nephrons?
Cortex and medulla
What is the functional unit of the kidney?
Nephron
What does the renal corpuscle consist of?
Glomerulus and Bowman’s capsule
What substances enter the filtrate during ultrafiltration?
- Water
- Small solutes like glucose
- Urea
- Amino acids
- Ions
What is tubular reabsorption?
Substances are reabsorbed from tubules back to blood
Which tubule reabsorbs glucose and most mineral salts?
Proximal convoluted tubule
What is the process of tubular secretion?
Substances are moved from the blood into the tubular fluid of the nephron
What does the loop of Henle do?
Reabsorbs water and sodium chloride from the filtrate
What hormone regulates the rate of water loss from the body?
Anti-diuretic hormone (ADH)
What triggers the release of ADH?
Changes in blood volume/osmotic pressure detected by osmoreceptors in hypothalamus
What is the juxtaglomerular apparatus (JGA) involved in?
Maintaining blood pressure and volume
What cells produce renin in the JGA?
Granular cells
What does angiotensin II do?
Increases blood pressure
What are the components of acid-base balance regulation?
- Chemical acid-base buffer systems
- Respiration
- The kidneys
What happens during respiratory acidosis?
Lungs do not expel sufficient CO2, increasing H+ concentration
What develops when there is excessive acid in the body?
Metabolic acidosis
What develops when there is excessive loss of CO2 from the blood?
Respiratory alkalosis
What is the bicarbonate buffer system?
CO2 in the blood combines with water to form carbonic acid, which dissociates into bicarbonate ions and H+
What is the primary role of buffer systems?
Neutralising added acid or base to resist changes to pH
What is the pH range for normal blood?
7.35-7.45
What happens when blood pH is below 7.35?
Acidosis develops
What compensatory mechanism occurs during metabolic acidosis?
Increased breathing rate to excrete more CO2 and raise pH
