B2.2.2 Flashcards
What makes up human circulatory systems
Your circulatory system is made up of your heart and your blood vessels. It’s a closed system as blood remains in it.
What does blood do
It transports substances around your body to cells that need them
How many times does blood flow through the heart
Blood flows through the heart twice so it’s a double circulatory system.
what is the circulatory system in the body
You pump blood to your body organs and tissues. Oxygen and glucose diffuse out of blood into the cells. CO2 diffuses out of cells into blood. Blood travels back to the heart, which then pumps it to the lungs. CO2 diffuses out of blood to be removed from the body and O2 diffuses in. Blood returns to heart and the cycle starts again.
What are the 3 main types of vessels
Arteries, veins and capillaries. Tubelike structures that transport blood around the body. The hollow cavity in the centre is called the lumen.
What do arteries do
Arteries carry oxygenated blood (apart from the pulmonary artery) away from the heart under high pressure.
What do veins do
Veins return the blood to the heart. They have valves to stop blood flowing the wrong way.
What do capillaries do
Capillaries link arteries and veins in tissue and organs. They form semipermeable walls are only one cell thick , so substances can move through easily.
How does the artery withstand the high pressure
The artery has very thick muscular walls. The wall expands with the force of each contraction and snaps back to push the blood forward.
What do the veins look like
Low pressure in veins so thick vessel walls aren’t required. One way valves keep the blood from flowing back to the heart.
How are materials transferred very quickly around the body
The high pressure means materials are transported very quickly around the body.
