B3.2 Flashcards
What is plasma?
The liquid part of the cell which carries a number of important substances around the body
What important substances do plasma carry around the body?
- Dissolved food substances, e.g. glucose
- Hormones from their glands to target cells
- Plasma proteins, e.g. antibodies
- Waste substances, e.g. urea
How are red blood cells adapted to their function (transporting oxygen)?
- Small so they pass through small blood vessels
- Shaped like biconcave disks for large surface area to exchange oxygen quicker
- No nucleus so more haemoglobin can fit in
How is oxygen transported in the body?
Haemoglobin in the red blood cells react with oxygen in the lungs forming oxyhaemoglobin. This process is irreversible. When the oxyhaemoglobin reaches the tissue, the oxygen is released
Name the three types of blood vessels.
- Arteries
- Veins
- Capillaries
What is the role of the arteries?
It transports blood away from the heart to the tissues
What is the role of the veins?
It transports blood back to the heart from the tissues
What is the role of the capillaries?
It links arteries to veins and allows material to pass between the blood and the tissues
What structure does the arteries have which made it adapt to its special role?
It has a thick muscular wall to resist the high pressure
What structure does the veins have which made it adapt to its special role?
Large valves and lumen to try and keep the blood moving back to the heart because the pressure is low
What structure does the capillaries have which made it adapt to its special role?
It has permeable walls so substances can be transferred between the blood and the tissues
How many chambers does the heart have?
4.
2 at the top and 2 at the bottom
Which chambers are larger (the top or the bottom)?
The bottom
What are the bottom chambers called?
The left ventricle and The right ventricle
What are the top chambers called?
The left atria and the right atria
What is the role of the atria?
They receive blood from veins and then they contract and force blood through valves into the ventricles.
What does the ventricle do when it receives blood from the atria?
It contracts and force blood out of the semilunar valve into the pulmonary artery
What is the valve on the right side called?
The tricuspid valve and it has 3 lobes
What is the valve on the left side called?
The bicuspid valve and it has 2 lobes
What do the biscupid, tricuspid and semilunar valve all do?
Prevent any backflow of blood
Whats so special about the pulmonary artery and the aorta?
Only arteries in the body with valves. (They both have semi lunar valves)
What does the pulmonary artery do when it receives the deoxygenated blood?
It takes the deoxygenated blood to the lungs
What happens when the deoxygenated blood is taken to the lungs?
It discharges the carbon dioxide carried and absorbs oxygen
What happens when the blood leaves the lungs?
The blood now oxygenated leaves the pulmonary vein at low pressure into the left atrium which contracts to force the blood out of the bicuspid valve
What happens when blood is forced out of the bicuspid valve?
The blood is now leaving at a high pressure through the left ventricle and through the aorta which pumps the blood to the rest of the organs around the body
Why does the left ventricle have a thicker muscle wall than the right ventricle?
Because it has to pump blood all around the body instead of the lungs which are just close by
Why is the heart called a double circulatory system?
Because the blood is pumped to the lungs and is returned to the heart to be pumped into the body. This means that the blood is at a higher pressure and flows at the tissue at a higher rate
How do bacterial cells differ from plant/animal cells?
- They don’t ave any mitochondria or chloroplasts
2. They don’t have a “true” nucleus just a small string of DNA floating freely in the cytoplasm