9.2 HEART AND BLOOD Flashcards
What is the circulatory system made up of?
heart
blood
blood vessels
Name the missing label
Aorta
Name the missing label
Vena Cava
Name the missing label
Right Atrium
Blood moves around the body in three types of blood vessel:
Capillaries
Arteries
Veins
How is the structure of the arteries related to its function?
Thick muscles walls:
makes them strong and able to cope with the high pressure at which blood is pumped out by the heart.
Elastic fibres:
Allows them to stretch and spring back (recoil)
How is the structure of the veins related to its function?
Thinner walls that in arteries:
Blood is lower pressure
Wider lumen than arteries:
So many RBCs can flow at once
Valves:
To prevent the backflow of blood
How is the structure of the capillaries related to its function?
Thin walls:
So exchange of food, oxygen and waste can occur
No strong walls:
As blood pressure is low
What is the heart
A muscular organ that pumps blood around the body.
What structure prevents the backflow of blood between the chambers of the hearts?
Valves
What does a group of cells in the right atrium act as?
a pacemaker
What does a pacemaker do?
Controls the timing of the heart beat
What do valves do?
Prevents blood from flowing backwards
Where is backflow a problem?
In the veins
Function of the arteries
Transport blood away from the heart to the organs. They all carry oxygenated (contains oxygen) blood (apart from the pulmonary artery).
What would happen if capillaries had thicker walls and lower surface areas?
Food, oxygen would diffuse slower into cells and waste products would diffuse more slowly into the blood.
How have artery walls adapted to their function?
Thick layers made of muscle to make them strong and able to cope with the high pressure at which blood is pumped out by the heart.
Elastic fibres, allowing them to stretch and spring back.
Function of the capillaries:
Exchange food and oxygen from the blood into cells.
Exchange of waste products, such as carbon dioxide, out of the cells and into the blood.
The wall is only one cell thick – this reduces the diffusion distance for oxygen and carbon dioxide between the blood and the tissues of the body
Function of the veins:
Transport deoygenated (contains no oxygen) blood (apart from the pulmonary vein) from the organs back to the heart
Veins usually carry DEOXYGENATED blood into the heart.
Which vein is the exception?
Pulmonary Vein
Arteries usually carry OXYGENATED blood away from the heart.
Which artery is the exception?
Pulmonary Artery
What does pulmonary mean?
Anything related to the lungs.
Pulmonary Vein: Transports oxygenated blood from the lungs to the heart
Pulmonary Artery: Transports deoygenated blood from he heart to the lungs.
What branches into smaller vessels called capillaries?
Arteries
How do veins differ from arteries?
Carry deoxygenatedblood
Have valves
Have a low blood pressure
Have a wide cross section
