Biology 11–12 · Year 11

Elastic recoil of artery and vein rings under load

Module 2: Organisation of Living Things (Organisation of Cells; Transport)

PracticalMedium risk

School laboratory, not for home

In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.

The idea

Artery walls stretch and spring back while vein walls stretch and stay stretched, a difference in tissue that matches their different jobs in a closed circulation.

Safety card

Medium riskA teacher supervises

Setting: In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.

Hazards

Tissue may snap and flick
Microorganisms on raw tissue

Controls

Eye protection
Clear the bench of personal items; disinfect after; wash hands thoroughly
Offer an alternative task to any learner who opts out

Note

The aorta and vein are cut from a pluck or heart bought from a butcher or an abattoir; disinfectant per RiskAssess (https://www.riskassess.com.au/). NSW permits the dissection of animal parts bought from a butcher, supermarket or abattoir, no learner can be compelled to dissect, and any other source needs Schools Animal Care and Ethics Committee approval (https://education.nsw.gov.au/teaching-and-learning/animals-in-schools/animals-in-schools-issues/dissection-of-animals); the Department's Animals in Schools framework sets out the school's wider obligations (https://education.nsw.gov.au/teaching-and-learning/animals-in-schools).

What you need

Rings about 2 mm wide cut from an aorta and from a large vein (from a butcher's pluck or heart with vessels), 2 of each
Clamp stand; hook or paper clip; mass carrier with five 10 g and five 50 g masses, a total of 300 g, which is what the source equips each group with because a sample may support that much; ruler
Eye protection; gloves; disinfectant

How to do it

Hang a ring from the hook and attach the mass carrier; record the ring's length.
Add 10 g and record the stretched length; remove the mass and record the length after 30 seconds.
Repeat, adding 10 g at a time to 50 g and then 50 g at a time to a total of 300 g or until the ring will hold no more, whichever comes first, recording the loaded and unloaded lengths at each step.
Repeat with the vein ring, then with the second ring of each type.
Calculate percentage stretch under each load and percentage recovery after unloading; plot both against load for each vessel.
Disinfect the bench and wash hands.

What you should see

The artery ring extends under each load and returns close to its original length when unloaded; the vein ring extends more easily and recovers less, so its unloaded length creeps upward across the series. The learner knows it worked when the artery's recovery curve stays near 100 percent while the vein's falls away.

What changes

What you change: vessel type (artery or vein) and load (g)
What you measure: percentage stretch and percentage recovery
What you keep the same: ring width
time under load and after unloading
temperature
animal source

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

Arteries are rigid pipes; they stretch with each pulse and recoil to keep blood flowing.
Veins have thick walls because they carry blood back uphill; their walls are thin and rely on valves and muscle squeezing.
Stretchier means stronger; the vein stretches more and recovers less.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Biology Stage 6 Syllabus (2017), current: Year 11 taught to the end of 2026 and Year 12 to Term 3 2027BIO11-9 BIO11/12-4 BIO11/12-6
Biology 11–12 Syllabus (2025), Year 11 focus area Cells to systems; new syllabus not yet taught: Year 11 from Term 1 2027, Year 12 from Term 4 2027BI-11-02
Biology 11–12 Syllabus (2025), Year 11 Working scientifically; new syllabus not yet taught: Year 11 from Term 1 2027, Year 12 from Term 4 2027BI-11WS-04 BI-11WS-06
Australian Curriculum v9No Australian Curriculum v9 code is listed.

Sources

The pages the author read to write this activity.

All Concept Studio activities