B2.2.2 - Circulatory System Flashcards
What is your circulatory system made up of?
Your heart and blood vessels
What is it known as if blood remains with the heart and blood vessels?
The closed system
What is blood good for?
Transporting substances around your body that need them
Carrying away waste products
Give an example of a good substance blood carries around
Oxygen
Glucose
Give an example of a waste product blood gets rid of.
Carbon dioxide
How many times does blood flow through the heart during each circuit of the body?
Twice
Why is it called the double circulatory system?
The blood flows through the heart twice every circuit
What colour would you draw oxygenated blood?
Red
What colour would you draw deoxygenated blood?
Blue
Explain the process of the circulatory system.
Your heart pumps look out to your organs and tissues. The oxygen and glucose in the blood diffuses into them, as the carbon dioxide diffuses out. The blood travels back to the heart, which pumps it to the lungs. In the lungs the carbon dioxide diffuse out of the body while new oxygen diffuses in. Cycle repeat.
What are the 3 main types of blood vessels?
Arteries
Veins
Capillaries
What do blood vessels do?
They are tubelike structures through which blood flows through
What specific job does arteries do?
Carry blood away from the heart under high pressure
What specific jobs do veins have?
Return blood to the heart, and stop blood from flowing the wrong way
What feature do veins have that prevents blood from flowing the wrong way?
Valves
What specific job does capillaries have?
Link arteries and veins in tissues and organs. They form a network so every cell is close to a capillary.
Describe the walls of a capillary.
They are semipermeable, and they are only one cell thick, meaning that substances can easily go through them.
Describe the job of the artery.
The strong contractions of the heart cause the blood to be at very high pressure. To withstand the high pressure waves are created when the heart beats the arterial wall, which is thick and muscular. The wall expands after each wave and then snaps back (recoil) to push the blood forward.
Why are thick vessel walls not required in veins and capillaries?
The blood pressure through capillaries and veins are very low
Why is the double circulatory system beneficial?
As the heart pumps twice, it leaves the blood at a high pressure, as there isn’t as far to travel. This means the materials needed in the body are transported around quicker.
Describe the structure of a capillary.
Tube shape
Very small lumen
Single cell layer wall
Describe the structure of a vein
Fairly thin outer wall
Thin layer of muscle and elastic outer fibre
Smooth lining
Large lumen
Describe the structure of an artery.
Thick outer wall
Thick layer of muscle and elastic fibres
Small lumen
Smooth lining
