Blood Vessels & Circulation
Once blood leaves the heart it travels through a branching network of vessels, and the three types are easiest to tell apart by their jobs. Arteries carry blood away from the heart under high pressure, so they have thick, elastic walls. Capillaries are the microscopic vessels where the real business happens — oxygen, nutrients and waste pass across their paper-thin walls. Veins carry blood back to the heart at low pressure, using valves to stop it draining backwards. Layered on top is the split between the pulmonary circuit to the lungs and the systemic circuit to everywhere else.
Practice this set for free — no account needed. Loads 16 flashcards into the learner. The learner asks it as shown here: phrase first, meaning second.
Practice in the free learnerHow to study this set
Anchor everything to one rule: “arteries away, veins toward the heart”. Then handle the two famous exceptions on their own — the pulmonary artery carries deoxygenated blood and the pulmonary veins carry oxygenated blood — so that the general rule stays clean and the exceptions do not blur it. Picture the figure-of-eight: heart to lungs and back, then heart to body and back.
All 16 flashcards
Swap question and answerArteries, veins and capillaries
What are the three main types of blood vessel?
Away from the heart
In which direction do arteries carry blood?
Towards the heart
In which direction do veins carry blood?
To withstand the high pressure of blood pumped directly from the heart
Why do arteries have thick, muscular, elastic walls?
The aorta
What is the largest artery in the body?
It carries oxygenated blood from the left ventricle to the rest of the body.
The capillaries
Which are the smallest blood vessels, where exchange with the tissues takes place?
So that gases and other substances can diffuse quickly between the blood and the tissues
Why do capillaries have walls that are only one cell thick?
Oxygen, carbon dioxide, nutrients and waste products
What is exchanged between the blood and the tissues across the capillary walls?
Valves
What feature do many veins contain to stop blood flowing backwards?
The circuit that carries oxygenated blood from the heart to the body and returns deoxygenated blood to the heart
What is systemic circulation?
The circuit that carries blood between the heart and the lungs
What is pulmonary circulation?
Oxygenated blood
In systemic circulation, do arteries carry oxygenated or deoxygenated blood?
Deoxygenated blood
In systemic circulation, do veins carry oxygenated or deoxygenated blood?
The pulmonary artery
Which artery is the exception that carries deoxygenated blood?
It carries deoxygenated blood from the right ventricle to the lungs.
The pulmonary veins
Which vessels are the exception that carry oxygenated blood in veins?
They carry oxygenated blood from the lungs back to the left atrium.
In the lungs, in the capillaries surrounding the air sacs (alveoli)
Where does blood pick up oxygen and release carbon dioxide?
What to learn next
You have followed the blood through the vessels. Level 3, "Blood", zooms all the way in on the fluid itself — the red cells, white cells, platelets and plasma that the whole system exists to move.
Continue to Level 3: Blood →