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
- SL
Exam analysis
Chance of appearing4%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper1A
Typical marks1–2
Common command terms
- Identify
- State
- Explain
- Deduce
Scoring notes
- Common mistake
- Explaining venous flow without mentioning valves that prevent backflow.
Recent exam appearances
November 2025Paper1A ["SL"] · TZ115[ 1 ]B3.2.5—Vein adaptations
May 2025Paper1A ["SL"] · TZ115[ 1 ]B3.2.5—Vein adaptations
May 2019Paper3 ["SL"] · TZ13(b)[ 2 ]B3.2.5—Vein adaptations
November 2011Paper2 ["SL"] · TZ02(b)(i)[ 2 ]B3.2.5—Vein adaptations
May 2011Paper3 ["SL"] · TZ2B1(a)(i)[ 1 ]B3.2.5—Vein adaptations
Practice this objective
Coverage 2011–2025 · 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.