2.3.4

Blood Vessels - Veins

Test yourself

Veins

Veins form when capillaries join up after passing through the body. They transport deoxygenated (contains no oxygen) blood (apart from the pulmonary vein) from the organs back to the heart. They are different to arteries because:

Illustrative background for Thinner walls than arteriesIllustrative background for Thinner walls than arteries ?? "content

Thinner walls than arteries

  • The walls are thinner than those found in the arteries as the blood is at a lower pressure.
Illustrative background for Wider cross-section (lumen) than arteriesIllustrative background for Wider cross-section (lumen) than arteries ?? "content

Wider cross-section (lumen) than arteries

  • Low pressure hinders blood flow. This means that veins have a wider cross-section through which blood can flow to counteract this.
Illustrative background for ValvesIllustrative background for Valves ?? "content

Valves

  • Veins have valves to prevent the backflow of blood.

Jump to other topics

1Cell Biology

1.1What's in Cells?

1.2Cell Division

1.3Transport in Cells

2Organisation

2.1Principles of Organisation

2.2Enzymes

2.3Circulatory System

2.4Non-Communicable Diseases

2.5Plant Tissues, Organs & Systems

3Infection & Response

4Bioenergetics

5Homeostasis & Response

5.1Homeostasis

5.2The Human Nervous System

5.3Hormonal Coordination in Humans

5.4Plant Hormones

6Inheritance, Variation & Evolution

7Ecology

Go student ad image

Unlock your full potential with GoStudent tutoring

  • Affordable 1:1 tutoring from the comfort of your home

  • Tutors are matched to your specific learning needs

  • 30+ school subjects covered

Book a free trial lesson