The Blood and Immunity Flashcards
What does the blood consist of and how much percentage of is there.
RBC (red blood cells), WBC ( white blood cells) and plasma and platelets
45% = RBC, WBC and platelets
55%= plasma
Red blood cell structure
Biconcave discs containing no nucleus but plenty of protein haemoglobin
White blood cell structure
Large cells containing nucleus, different types have slightly different structure and functions.
Platelets structures
Fragments of cells
Plasma structure
straw coloured liquid
Role of plasma and what it carries and importance.
Plasma is the liquid which carries the components in the blood, e.g. cells, platelets, amino acids, hormones etc.
Important for transport of CO2, digested food, urea, hormones and heat energy.
Where does the plasma carry carbon dioxide
Carries waste CO2 away from respiring cells to the lungs for exhalation
Where does the plasma carry digested food
Carries digested food(amino acids, glucose) to cells for respiration or assimilation ( absorption of nutrients)
Where does the plasma carry Urea
Waste made in the liver as a result of the deamination of of amino group carried by plasma to kidney for excretion in urine.
Why does the plasma carry Hormones
Made in endocrine glands, secreted into plasma and sent to target organ to simulate changes in body conditions.
Where does the plasma carry Heat energy
Plasma is mainly made out of H2O which has high heat capacity so in crucial for maintain balanced temperature in body.
What does the RBC do
Red blood cells transport oxygen around the body from the lungs to cells which require it for aerobic respiration
Why does RBC have haemoglobin and what is haemoglobin
Has large quantity of haemoglobin (protein that combines oxygen ) to allow cell to transport oxygen to respiring cells.
Why does RBC have no nucleus
No nucleus so more space in the cell for haemoglobin, allowing more oxygen to be transported to respiring cells.
Why are RBC small and flexible
Allows them to squeeze through narrow capillaries and blood vessels without getting stuck.
Why does RBC have a biconcave
Flattened disc to allow greater surface area to volume ratio to increase diffusion rate of oxygen.
What does the WBC do
White blood cells are part of the body’s immune system, defending against infection by pathogenic microorganisms
What are the two main types of WBC
two main types, phagocytes and lymphocytes
What does Phagocytes do and how.
- Carry out phagocytosis by engulfing and digesting pathogens.
1. have a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
2. Once encountered, they release digestive enzymes to digest it
3. The pathogenic cells can be recognised easily by their multi-lobed nucleus and their ability to change shape easily.
4. They do it to all pathogenic cells they encounter and it is known as non-specific immune response.
What does Lymphocytes do and how.
- Produce antibodies to destroy pathogenic cells and antitoxins to neutralise toxins released by pathogens
1. Make antibodies ( protein molecules) which stick to antigens on a pathogenic cell.
2. This triggers pathogen to be destroyed by enzymes split opening the pathogen cell membrane.
3. It makes it easier for Phagocytes to find it.
4. Also causes agglutination (clumping together) of pathogens making it harder for them to damage our cells and make it easier for phagocytes to find.
What are some features of the Lymphocytes and what is immunity
- The antigens they produce are very specific to to that type of cell.
- Since each lymphocyte only make one type of antibody makes it harder for body to find specific one for that pathogen making you sick.
- After the first time Lymphocytes produce memory cells retain the instructions for making those specific antibodies for that type of pathogen.
- Therefore it can produce antigens before the pathogen cells can make you sick
* This is known as immunity as you can’t get sick from the same pathogen the second time.
What is vaccination and how does it work?
- Involves introducing small quantities of dead or inactive forms of pathogens to enter the body.( can’t lead to a disease in a patient.)
- The WBC are stimulated to produces antibodies against the dead pathogen, they attach themselves to the antigen in order to make memory cells
- Same time WBC divides by mitosis and make many copies of themselves.
- These memory cells or WBC stay in the blood for decades, so if the same pathogen enters the body, antibodies are produced quick and infection would be prevented.
What are platelets and what’s the need for blood clotting.
Platelets are blood fragments which are involved in blood clotting. This prevents continued / significant blood loss from wounds. A scab is formed sealing the wound with insoluble patch that prevents entry of microorganisms that could cause infection and remains until skin heals under it.
How are platelets involved in the clotting of blood?
- When there is a wound collagen is exposed which attracts platelets to the area.
- They quickly build a barrier preventing much blood loss.
- Platelet release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin
- This forms a insoluble mesh across the wound trapping RBC therefore forming a clot.(the fibrin make the clot stronger. )
- clot eventually dries and develops into a scab to protect the wound from bacteria entering