1.2.2

Blood Vessels

Test yourself

Arteries

Arteries are a type of blood vessel.

Illustrative background for Thick wallsIllustrative background for Thick walls ?? "content

Thick walls

  • Arteries are the largest in external (outer) diameter and have the thickest walls of all blood vessels.
    • Because they have such thick walls, they have a slightly smaller lumen (internal diameter).
Illustrative background for Can vasoconstrict and vasodilateIllustrative background for Can vasoconstrict and vasodilate ?? "content

Can vasoconstrict and vasodilate

  • During exercise, the body can vasoconstrict (make the lumen smaller) or vasodilate (make the lumen larger) to distribute blood efficiently.
    • E.g. the arteries leading to the stomach will vasoconstrict to reduce blood flow to ‘non-essential’ organs. At the same time, the arteries leading to the working muscles will vasodilate to increase blood flow to where the blood is needed most at that time.
Illustrative background for Elasticated wallsIllustrative background for Elasticated walls ?? "content

Elasticated walls

  • Arteries are elasticated and thick. This lets them cope with the high pressures at which blood is pumped away from the thick, muscular ventricles of the heart. This is why you can feel a pulse in them.
    • Think of the walls of arteries like elastic bands. They can stretch to cope with the high pressures from the heart but then return to their original shape and size. This prevents them from bursting.

Veins

Veins are another type of blood vessel.

Illustrative background for StructureIllustrative background for Structure ?? "content

Structure

  • Veins have a large internal diameter (lumen) but thin walls as the pressure inside them is low.
  • Veins have valves to prevent the backflow of blood, which is a possibility due to the lower pressures. This means that they do not have a pulse.
Illustrative background for FunctionIllustrative background for Function ?? "content

Function

  • Veins carry blood towards the heart (mostly deoxygenated blood).

Jump to other topics

1Applied Anatomy & Physiology

2Movement Analysis

3Physical Training

4The Principles of Training

5Using Data

6Sports Psychology

7Socio-cultural Influences

8Health & Fitness

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