2h Transport in Humans Flashcards
Describe three features of red blood cells.
Red, biconcave shape & no nucleus to maximize capacity for haemoglobin
Describe three features of white blood cells.
Large cells with large nuclei, fight diseases, 2 types: lymphocyte & phagocyte
Describe two features of platelets.
Stick together to make blood clot, are fragments of dead cells
Describe three features of plasma
make up around 60% of blood volume, mostly water, waste and products of digestion are transported, straw colored fluid
What is the percentage composition of blood?
55% Plasma
45% Red Blood Cells
<1% Platelets and White Blood Cells
What does plasma transport?
Carbon dioxide, urea, digested food, hormones, heat energy
How is the red blood cell adapted to be suitable for oxygen transport?
It is biconcave and has no nucleus to allow max. capacity for haemoglobin which carries oxygen. Its biconcave shape allows bending so it can fit through capillaries
Describe the primary immune response and how it works in vaccination
As a pathogen enters the body, the organism’s white blood cells called lymphocytes produce specific antibodies, and eliminate the disease by attaching to the pathogen’s specific antigen, and memory cells are created. Phagocytes ingest pathogens. For vaccination, a weakened pathogen enters so the organism doesn’t get too sick.
Explain what happens in the secondary immune response as a result of prior pathogen infection or vaccination
When a pathogen enters the body again, the memory cells recognize the pathogens & produce antibodies more quickly & in greater quantity. The specific antibodies will be able to kill the pathogen before it harms the body. This is the secondary immune response.
How do platelets make blood clots?
Release chemicals that convert soluble fibrinogen proteins into insoluble fibrin, forms an insoluble mesh
Traps red blood cells, which clot and develops into a scab
What is the use of blood clotting?
It helps prevent excessive blood loss and protect wound against pathogens entering.
Explain the structure of an artery and how it is adapted to its function.
Arteries have no valves, small lumen and thick, strong walls to increase the blood pressure. This is needed to pump oxygenated blood throughout the body efficiently, and maintain blood flow despite resistance.
Explain the structure of an vein and how it is adapted to its function.
Veins have valves to prevent backflow.
Veins have a large lumen and thin walls, so there is less blood pressure, and more blood can be carried in the wide lumen at once.
Explain the structure of a capillary and how it is adapted to its function.
They have very thin walls which allows for efficient exchange of gases, nutrients, and waste
Why does heart rate increase after exercise?
Because more oxygen needs to be supplied to the muscles.
What are the effects of adrenaline on the heart?
Increases heart rate, to supply oxygen and glucose for respiration in muscle cells.
What are the effects of adrenaline on the blood vessels?
It constricts blood vessels, so they move more blood to the important organs.
