B3.2 The blood system Flashcards
What transports substances around the body?
The circulatory system
What is the heart?
An organ
What does the heart do?
Pump blood around the body
What is much of the wall of the heart made from?
Muscle tissue
How many chambers are there in the heart?
Four
What are the names of the four chambers?
The left and right atria and the left and right ventricles
What does the blood enter?
The atria
What does the atria do?
Contract and force blood into the ventricles
What do the ventricles do?
Contact and force blood out of the heart
What do the valves in the heart ensure?
The blood flows in the correct direction
What does blood flow from the heart and to the organs through?
The arteries
Arteries =
Away
What does the blood return to the heart through?
The veins
What are the two different circulation systems for?
The lungs and one for all the other organs of the body
What blood vessels are associated with the heart?
Aorta, vena cava, pulmonary artery and the pulmonary vein
What do arteries have?
Thick walls containing muscle and elastic fibres
What do veins have?
Thinner walls and often valves to prevent back-flow of blood
When are stents used and what for?
If arteries begin to narrow and restrict blood flow, stents are used to keep them open
In the organs what does blood flow through?
Capillaries
What are capillaries?
Thin-walled blood vessels
What passes through the capillaries?
Substances needed by the body cells in body tissues pass out of the blood and substances produced in the cells pass into the blood
What is blood?
A tissue
What does blood consist of?
A fluid called plasma in which red blood cells, white blood cells, and platelets are suspended
What does blood plasma transport?
Carbon dioxide from the organs to the lungs, Soluble products from digestion from the small intestine and other organs, urea from the liver to the kidneys
What do red blood cells transport?
Oxygen from the lungs to the organs
What do red blood cells not have?
A nucleus
What are red blood cells packed with?
Haemoglobin
What does haemoglobin combine with oxygen in the lungs to produce?
Oxyhaemoglobin
Where is oxyhaemoglobin split up?
In other organs back into oxygen and haemoglobin
Do white blood cells have a nucleus?
Yes
What do white blood cells form?
Part of the body’s defence system against microorganisms
What are platelets?
Small fragments of cells
Do platelets have a nucleus?
No
What platelets help to do?
Clot blood at the site of a wound
What does the xylem tissue transport system in plants do?
Transport water and mineral ions from the roots to the stem and leaves
What is the transpiration stream?
The movement of water from the roots through the xylem and out of the leaves
What does the phloem tissue carry?
Dissolved sugars from the leaves to the rest of the plant, including the growing region and the storage organs
