New
New
Year 11
OCR
Foundation

Controlling water balance: the kidneys, and nephron structure

I can describe the role of the kidneys in filtering the blood to control the water balance of the human body, and the structure of a nephron.

New
New
Year 11
OCR
Foundation

Controlling water balance: the kidneys, and nephron structure

I can describe the role of the kidneys in filtering the blood to control the water balance of the human body, and the structure of a nephron.

Lesson details

Key learning points

  1. The kidneys are organs of the human excretory system; blood passes through the kidneys and is filtered.
  2. Water and urea diffuse out of the blood plasma into kidney tubules to be excreted as urine, including nephron structure.
  3. The kidneys reabsorb as much water as needed from the urine into the blood plasma to maintain water balance in the body.
  4. Having too much water in the body leads to dilute urine, and vice versa.

Common misconception

Misconceptions about the roles of the kidneys, bladder and how the blood is 'cleaned' exist. Students often conflate/confuse these roles, muddle key terms or offer weak descriptions or explanations.

The roles of the kidney and bladder are clearly described, and diagrams and flowcharts are used to support the detailed explanations. Tasks that reinforce understanding and check for clarity and correct use of key words are included too.

Keywords

  • Urea - a waste product created in the process of breaking down excess proteins and amino acids

  • Blood plasma - the liquid part of the blood which contains dissolved nutrients and waste products

  • Kidney - the organ in the excretory system which filters waste products from blood plasma and controls water balance

  • Excretory system - the organ system responsible for removing waste from blood plasma

  • Urine - a combination of waste urea, water and other substances which is stored in the bladder until urinated

Relate this content to their own experiences when they have either drunk a lot or very little, although stick to key facts and terms to avoid crass language or embarrassment.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What substance is stored in the bladder?
Correct Answer: urine
Q2.
Match the constituent of blood to its description.
Correct Answer:red blood cells,transports oxygen to cells

transports oxygen to cells

Correct Answer:white blood cells,play a huge role in immunity

play a huge role in immunity

Correct Answer:platelets,are involved in blood clotting

are involved in blood clotting

Correct Answer:plasma,contains dissolved substances such as glucose and ions

contains dissolved substances such as glucose and ions

Q3.
Label these parts of the excretory system.
An image in a quiz
Correct Answer:a,ureter

ureter

Correct Answer:b,bladder

bladder

Correct Answer:c,urethra

urethra

Correct Answer:d,kidney

kidney

Q4.
What are proteins made of?
Correct Answer: amino acids
Q5.
Which of these are ions?
Water
Correct answer: Na+
Correct answer: K+
Correct answer: HCO$$_3$$-
CO$$_2$$
Q6.
The process that uses glucose as a fuel to transfer energy for life processes is called cellular .
Correct Answer: respiration

6 Questions

Q1.
Which body system are the kidneys part of?
An image in a quiz
digestive
waste
Correct answer: excretory
glandular
circulatory
Q2.
Which of the following are too large to leave the blood during the filtering process?
glucose
Correct answer: proteins
urea
ions
cells
Q3.
Which substances are filtered from the blood and removed from the body in urine?
Correct answer: water
Correct answer: ions
carbon dioxide
Correct answer: urea
glucose
Q4.
Which substances are reabsorbed by the kidney tubules?
Correct answer: water
Correct answer: glucose
urine
urea
carbon dioxide
Q5.
Match each part of the kidney tubule (nephron) to its correct name.
An image in a quiz
Correct Answer:a,glomerulus and Bowman’s capsule

glomerulus and Bowman’s capsule

Correct Answer:b,proximal convoluted tubule

proximal convoluted tubule

Correct Answer:c,loop of Henlé

loop of Henlé

Correct Answer:d,collecting duct

collecting duct

Q6.
If you drink too much water, which of these will happen?
small quantity of urine
Correct answer: dilute urine
concentrated urine
Correct answer: large quantity of urine
strong smell
Q1 Macrovector/Shutterstock