3.17 - Kidneys 2 - Anatomy & Nephrons

• What are the three main roles of the kidneys?

  Remove waste, regulate ions, regulate water
• Through which arteries does blood enter the kidneys?

  Renal arteries
• What do the kidneys produce from the filtered blood?

  Urine
• How does urine exit the kidneys?

  Through the ureters to the bladder
• What is the first step in urine formation?

  Filtration in the glomerulus
• What is the name of the tangle of blood vessels involved in filtration?

  Glomerulus
• What is filtered into the Bowman's capsule?

  Liquid part of the blood
• What types of substances can be filtered through to the Bowman's capsule?

  Water, amino acids, urea, glucose, ions
• What percentage of plasma is filtered through to the Bowman's capsule?

  About 20 percent
• What happens to the blood that is not filtered?

  It continues through the blood vessels
• What is the process called when the kidneys reabsorb useful substances back into the blood?

  Selective reabsorption
• Which substances are almost entirely reabsorbed by the kidneys?

  Glucose and amino acids
• What do the kidneys absorb none of during reabsorption?

  Urea
• What are the parts of the nephron in order?

  1. Glomerulus
  2. Bowman's capsule
  3. Proximal convoluted tubule
  4. Loop of Henle
  5. Distal convoluted tubule
  6. Collecting duct
• What is classified as urine after passing through the nephron?

  Fluid from the collecting duct
• What happens to urine after it is formed?

  It passes down the ureter to the bladder
• What is the final step in the urinary system process?

  Urination through the urethra
• Blood enters the kidneys via the renal arteries and leaves via the renal veins.
• B

  
• Ureters

  
• E

  
• Which structure carries urine from the bladder out of the body? 

  Urethra
• Nephron

  
• Glomerulus

  
• A

  
• Between which two structures does filtration (sometimes called ultrafiltration) take place? 

  • Bowman's capsule
  • Glomerulus 
• On the diagram below, the highlighted structure is called the collecting duct.

  
• Letter A indicates the proximal convoluted tubule, whilst letter B represents the distal convoluted tubule.

  
• Loop of Henle

  
• Selective reabsorption is the process whereby certain molecules (e.g. ions, glucose, and amino acids), are reabsorbed from the filtrate, as it passes through the nephron.
• True or false? Selective reabsorption takes place throughout the nephron.

  True
• How much urea is selectively reabsorbed? 

  None
• How many ions are selectively reabsorbed? 

  It depends on how many we already have in the blood
• How much glucose is selectively reabsorbed? 

  Almost all