blood and organs Flashcards
(49 cards)
what are the 4 main components of blood
- plasma
- platelets
- red blood cells
- white blood cells
what is plasma
it is the liquid bit of your blood. it is the blood minus the blood cells
what colour is plasma
pail yellow liquid that carries just about everything that needs transporting around your body
what are platelets
they are small fragments of cells that help blood clot
what is in plasma
- red and white blood cells and platelets
- digested food products ( like glucose and amino acids) from the gut to all the body cells
-carbon dioxide from the body cells to the lungs - urea from the liver to the kidneys
- hormones which act as a chemical messengers
- heat energy
what happens when you damage a blood vessels
platelets clump together to ‘plug’ the damaged area
this is known as blood clotting. blood clots stop you losing too much blood and prevent micro organisms from entering the wound.
in a clot. platelets are held together by a mesh of a protein called fibrin
what is the job of the red blood cell
to carry oxygen
how do red blood cells work
- they transport oxygen from the lungs to all cells in the body.
how are red blood cells well adapted to its function
- red blood cells are small and have a biconcave shape to give a large surface area for absorbing and releasing oxygen
- they contain haemoglobin which is what gives blood its colour - it contains lots of iron. in the lungs, haemoglobin reacts with oxygen to become oxyhaemoglobin. in the body tissues the reverse reaction happens to release oxygen to the cells
- red blood cells do not have a nucleus - this frees up space for more haemoglobin, so they can carry more oxygen.
what does white blood cells deal with
pathogens
what are pathogens
they are micro organisms that cause disease
what happens when pathogens have entered the body
they will reproduce rapidly unless they are destroyed. that is the job of the immune system and white blood cells are the most important part of it.
what are the two types of white blood cells
phagocytes
lymphocytes
what do phagocytes do
they detect things that are ‘foreign’ to the body, eg pathogens. they then engulf the pathogens and digest them.
phagocytes are non specific - they attack anything that is not meant to be there
what do lymphocytes do
produce antibodies
what happens when lymphocytes come across a foreign antigen
the lymphocytes will produce proteins called antibodies - these lock on to the invading pathogens and mark them out for destruction by other white blood cells. the antibodies produced are specific to that type of antigen - they won’t lock on to any others
what are the unique molecules on the surface of the pathogen
anitgen
what do antibodies then do
they produce rapidly and flow around the body to mark all similar pathogens
what are memory cells
they are produced in response to a foreign antigen. these remain in the body and remember a specific antigen. they can reproduce very fast if the same antigen enters the body again.
what is vaccination
can protect from future infection
what happens when you are infected with a new pathogen
it can take your lymphocytes a while to produce the antibodies to the deal with it, you can get very ill and even die.
how can you avoid some diseases
vaccinated
state –> blood vessels are designed for their function
what does vaccination involve
injecting dead or inactive pathogens into the body. these carry antigens, so even though they are harmless, they still trigger an immune response - your lymphocytes produce antibodies to attack them
memory cells will also be produced and will remain in the blood, so if live pathogens of the same type ever appear, the antibodies to kill them will be produced much faster and in greater numbers.
