B3.2.5—Vein adaptations
Veins return low-pressure blood to the heart using valves, wide lumens and flexible walls that can be compressed by surrounding muscles.
- Syllabus
- First assessment 2025
- Objective
- B3.2.5
- Level
- HL
Exam analysis
Chance of appearing1%of analysed past papers
Latest appearanceMay 2025
Most common paperPaper1A
Typical marks1
Common command terms
- Identify
- State
- Explain
- Deduce
Scoring notes
- Common mistake
- Explaining venous flow without mentioning valves that prevent backflow.
Recent exam appearances
May 2025Paper1A ["HL"] · TZ324[ 1 ]B3.2.5—Vein adaptations
Practice this objective
Coverage 2025–2025 · Updated 15 Jul 2026
Concept essentials
- Vein valves keep blood moving toward the heart.
- Large venous lumens reduce resistance during low-pressure return.
- Flexible vein walls can be compressed by skeletal muscles.
- Veins have less elastic and muscle tissue than arteries.