Chapter 7 / 5 short lessons
Excretion in humans
Follow waste from cells to the outside, and explain how kidneys filter blood while retaining useful substances.
G3 Pure Biology / K325 / 2027 syllabus
What do you think?
Glucose is present in fluid just filtered from healthy blood, but normally absent from urine. What happened?
Lessons
0 of 5 marked as readExcretion: removing metabolic waste
Define excretion and explain why metabolic wastes and excess substances must be removed.
About 4 minThe urinary system
Identify the kidneys, ureters, bladder and urethra and explain their functions.
About 4 minUltrafiltration in the kidney
Explain pressure-driven ultrafiltration at the glomerulus and Bowman's capsule.
About 5 minSelective reabsorption
Explain selective reabsorption and use data to distinguish filtrate from urine.
About 5 minHow dialysis removes waste
Explain dialysis using membrane permeability, gradients and flowing dialysis fluid.
About 5 minWhat you will be able to do
- Distinguish excretion from egestion.
- Trace blood and urine through their separate routes.
- Explain ultrafiltration and selective reabsorption.
- Use concentration gradients and membrane properties to explain dialysis.
Spaced review
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