transport in man Flashcards
why is there a need for a transport system?
diffusion is inadequate for transport.
- high surface to seas volume ratio
- high distance away
what is the need for double circulation
- allows blood entering the lung to be transported at a lower pressure, so that there is more time to by reoxygenated
- allows bloos in the systemic circulation to be pumped at a high pressure so that it can quicky reach all tissues
proper terms for RBC, WBC, platelets and plasma
erythrocytes, leucocytes, thrombocytes, plasma
structure and function of erythrocyte
- has haemoglobin: bind reversibly to form oxyhaemoglobin, transport oxygen around the body
- has no nucleus: increase space for more haemoglobin to be packed, increase the rate of oxygen transported
- bioncave shape: increase SA to V ratio for quicker diffusion of oxygen
- elastic and flexible membrane: can change shape to sqeeze in small and narrow capillaries
rank the size of the sunstabces in blood from smallest to largest
platelets, red blood cells, white blood cells
what is the effect of having sickle cell anaemia
what happens during a drop in fitness level?
what are the 2 types of white blood cells
phagocytes and lymphocytes
what is the function of lymphocytes
product antibodies that:
- neutralise toxins produced by bacteria
- recognise and bind to bacteria, causing them to rupture
- recognise and bind to bacteria, for tagging for phagocytosis by phagocytes
-cause bacteria to clump together, so that they can be easily ingested by phagocytes
why the need for phagocytes?
they can carry out phagocytosis on bacteria
they engulf and ingest bacteria
after that they die and form pus
what happens when there is tissue rejection?
the immune system recognises the transplant organ as foreign tissue
starts producing antibodies to destroy the transplanted organ (phagocytosis)
how to prevent tissue rejection
- immunosupression
- be more susceptible to other infections. immune system is comprimised - organs transplant from a genetically close donor
- same person/identical twin CANNOT have tissue rejection
which blood groups are universal donors? which blood groups are universal recipient? why?
- blood group O: they do not have any A or B antigens on the surface of the RBC, cannot recognise and bind to antibodies, hence no agglutination
- blood group AB: they do not have A or B antibodies in the blood plasma, cannot recognise and bind to antigens so there will be no agglutination
importance of blood clots?
- (entry of stuff IN): prevent the entry of bacteria into the wound
- (exit of stuff OUT): prevent the excessive loss of blood from the wound