Blood, Body Defences And Immunity Flashcards
What tissue best describes blood
Connective tissue
How much plasma and cells will separate in test tubes of whole blood that has been prevented from clotting
55% plasma
45% cells
What is the term used to describe blood cell formation in the bone marrow
Haemopoiesis
Which blood group in a universal donor
Blood group O
What does the red blood cells transport in the bloodstream
Oxygen and carbon dioxide
Do white blood cells (leukocytes) have nuclei
Yes, red blood cells are biconcave discs with no nuclei
What is the lifespan of red bloody cells
120 days
What is the breakdown or destruction of red blood cells called
Haemolysis
Is blood clotting (coagulation) positive feedback or negative feedback
Positive feedback
What is lymph and what does it do
A clear watery fluid that transports plasma proteins back to the bloodstream
It also carries away bacteria an cell debris from damaged tissues, which can then be filtered out and destroyed by lymph nodes
Which important constituent functions of blood is absent from lymph
erythrocytes
Which important protective cells are found within lymph nodes
Lymphocytes and macrophages
What substances are transported by blood
Oxygen Nutrients Hormones Heat Antibodies and immune cells Clotting factors Waste
Why give FFP (fresh frozen plasma)?
Give to patients in traumas
To do with bloody clotting - if you’ve lost a lot of blood you need and increase in your clotting factors
What is in blood
Plasma proteins Electrolytes Nutrients Wastes products Hormones Gases
Where are red blood cells reproduced
In red bone marrow
What does dietary folic acid and vitamin B12 promote
Hb synthesis and red blood cell Maturation
Why is dietary iron important
It is an essential constitute of haemoglobin
How long does it take for a red blood cell to mature into a fully active concave disc
7 days
How long does an erythrocyte circulate in the blood
120 day
What happens to old erythrocytes
They are dealt with my haemolysis mainly in the spleen
Anything good inside the cell is taken out and reused again and excreted through the body
What happens when you don’t have enough blood in the body
Tissue hypoxia
When can tissue hypoxia happen
If you’re enemic
Hypovolaemia
Altitude
Lung disease
What happens during tissue hypoxia if your enemic
You don’t have enough iron to make red blood cells - your red blood cells drops down - lost ability to carry oxygen to the tissues that need it
What’s happens during tissue hypoxia In hypovolaemia
Lost a lot of blood - lost a lot of internal circulating volume - inability to carry red blood cells
How can altitude affect tissue hypoxia
When you go higher up into atmosphere we start to lose oxygen in out atmosphere so our body has to work harder to get the oxygen out of the air and into the body to use it
How does lung disease affect tissue hypoxia
Deficiency in a way that the can either transport oxygen into the body or excrete waste out of the body (co2)
What happens in tissue hypoxia
Kidney secrete erythropoietin into blood
Bone marrow increases
Red blood cells numbers rise
Increased blood oxygen - carrying capacity reverses tissue hypoxia
How many erythrocytes are in the blood cells
99% (30 trillion in the body)
Features of biconcave disc
Increased surface area
Flexible
No nucleus (can’t replicate, increase oxygen carriage)
Why do red blood cells contain heamoglobin
Transport oxygen (each atom of iron can carry 1 oxygen molecule, 4 haem groups)
What do erythrocytes do
Release oxygen through low ph, low oxygen and increased temperature
What happens if you don’t get enough vitamin B12
Can make you tired
What happens to iron
It’s recycled, reused in bone marrow to form new haemoglobin
What happens to biliverdin
Formed from haem reduced to bilirubin and excreted in the bile, bile is excreted into the small intestine
What blood group is compatible with group A as a doner
Group A abs AB
What blood group is compatible with group B as a doner
Group B and AB
What blood group is compatible with group AB as a doner
Group AB
What blood group is compatible with group O as a doner
All groups (universal doner)
What blood group is compatible with group A as a recipient
Group A and O
What blood group is compatible with group B as a recipient
Group B and O
What blood group is compatible with group AB as a recipient
All groups (universal recipient)
What blood group is compatible with group O as a recipient
Group O
What is an antigen
Any molecule that triggers an immune response
How does immune systems respond to foreign antigens
By producing antibodies to get rid of them
What rhesus type makes rhesus antibodies
Rh-
Only stimulated to do so in certain circumstances such as incompatible blood transfusion or pregnancy
If a mother creates antibodies to rhesus negative and the father doesn’t and the foetus has the fathers gene and starts creates the opposite the the mother, what happens?
They will start to attack eachother, if the baby’s red blood cells get into mothers blood stream, her immune system will consider them foreign invaders and create antibodies to destroy them - these antibodies can cross the placenta and attach the foetus
What are leucocytes
White blood cells
Role in defence and immunity
They increase when there is an infection, trauma or malignancy
What are the 2 types of leycocytes?
Granulocytes
Agranulocytes
What do granulocytes contain
Neutrophils
Eosinophils
Basophils
What does agranulocytes contain
Monocytes
Lymphocytes
What’s the function of neutrophils
Protects against bacteria
Attracted by damaged cells which Release chemotaxis
What’s the function of eosinophils
Elimination of parasites -release toxic chemicals
Accumulation of allergic inflammation
Promote inflammation
Reduces inflammation -breakdown histamine
What’s the function of basophils
Promotes inflammation - release histamine and heparin
What does phagocytosis do
Digest bacteria -lysososomes
What is function of monocytes
Largest white blood cells (leucocyte)
Develop into macrophages
Can isolate indigested material
Produce IL1
What are lymphocytes
Found in lymphatic system
B cells and T cells
Each cell recognises 1 antigen
Allows the body to respond quickly to recognise disease
What are thrombocytes
Platelets
What do thrombocytes do
Promote blood clotting
1/3 or platelets stored in the spleen for emergency blood clotting
Cause vasoconstriction in damaged blood vessel
Sticky - clump together to block hole
Positive feedback- attract more platelets
Platelet plug
Plug stabilised but fibrin
What is the lymphatic system
Extensive tubular network adapted to assist in circulation of body fluids, taking excess fluid from interstitial spaces back to the bloodstream
What are the features of the lymphatic system
Thin, blind ended vessels found extensively around the body, extending into interstitial spaces
How does lymph fluid go through the lymph node
Afferent lymphatic -arriving
Efferent lymphatic -exiting
How is lymph fluid moved through the valves
By vascular resistance and your moment
Your movement helps squeeze the muscles around which helps your venous return in your veins but also works on lymph nodes
What are the lymphatic organs
Primary organs
Secondary organs
What are primary organs
Bone marrow (B cells)
Thymus (T cells)
Where cells are produced
What are secondary organs
Spleen (filters blood) Lymph nodes (filter lymph)
What happens in the capillary network in the lymphatic system
Fluid is forced out at the arterial side, fluid is reabsorbed in the venous side
What happens to excess fluid in the lymphatic system
Excess fluid the the tissues cell debris and bacteria absorbed into the lymph vessels
What do lymph vessels do if the lymphatic system
Return fluid to venous circulation
Prevents tissues from becoming swollen
What do immune cells do in the lymphatic system
Detect infection
How much lymph is filtered a day in the lymphatic system
3-4 litres of lymph a day
What are lymph nodes
Oval shaped masses of lymphatic tissue, contains in a connective tissue
Contain both t lymphocytes and b lymphocytes
What gets filtered out in lymph nodes
Foreign bodies and microorganisms (immune action)
Where is the immune system present
Majority of body’s tissues
What is the immune system
Complex interaction of chemical and cellular events designed to recognise non self materials
Both non specific and specific parts
What is non specific immunity
Front line of body’s defences against foreign particles and invading microorganisms
What are the front line of body’s defences against forge in particles invading microorganisms
Species resistance Inflammation Chemical barriers Fever Mechanical barriers
What is species resistance
Homo sapiens resistant to organisms other species may not be
What is inflammation
Tissue responses, specialist non specific cells
What are chemical barriers
Acids, enzymes, interferons, complement
What happens when you get a fever
Body becomes inhospitable to certain pathogens
What are mechanical barriers
Anatomical defences
What happens to body tissues (anatomical defences)
Body tissues are covered in membranes and epithelia which act as barriers - most are bathed in protective fluids
What does it prevent when surfaces are colonised by commensal microorganisms
Overgrowth of disease producing species
What are the types of anatomical defences
Skin Eyes Respiratory system Digestive system Urinary system
How is the skin an anatomical defence
Barrier to UV,
resistant to drying,
presence of salt and sebum,
commensal organisms
How are eyes an anatomical defence
Lids, lashes, brows, lubricating and antibacterial tears
How is the respiratory system and anatomical defence
Nasal hairs
Nasal microfolra
Mucociliary escalator
How is the digestive system and an anatomical defence
Antibacterial saliva
Acid sterilisation
Mucus
Intestinal microflora
How is the urinary system an anatomical defence
Flushing by sterile urine
Urine chemistry
What immunity is phagocitic cells (macrophages, neutrophils and eosinophils)
Non specific immunity
What do phagrocitic cells do? (Macrophages, neutrophils and eosinophils)
Migrate to sites of inflammation and infection
What is the natural killer cell
First line of defence against damaged, abnormal or infected cells
Can give the ‘kiss of death’ to abnormal cells which then self destruct
What do natural killers cells NOT require
Cooperation of antibody or other immune cells
What is specific immunity/adaptive specific to?
Each type of invader or particle
What does specific immunity/adaptive do?
Allows us to develop resistance to specific microorganisms
What does specific immunity/adaptive consist of
2 interdependent components - cell mediated immunity and humoral immunity
What is adaptive immunity
Can be active or passive
What is active adaptive immunity
Stimulation of the adaptive immune response - natural or vaccine induced
What is passive adaptive immunity
Acquire immunoglobulins directly either through injection or through the placenta during pregnancy or via breast milk whist feeding
What do antigens do
Induce specific immune responses - normally non self in origin
What is cell mediated immunity
The production of specific t-lymphocytes in the thymus(t cells), some of which attach to non self materials to destroy them
What is cell mediated immunity effective against
Antigens of fungi, bacteria, viruses and parasites, foreign tissue transplants, abnormal cells
What are the T cells and cell mediated immunity (in order)
Helper T cell
Cytoxic T cell
Suppressor T cell
Memory T cell
What does the helper T cell do
(CD4) assist in production of antibody by;
Cooperating with B cells
Secrete a chemical which stimulates the proliferation of cytoxic T cells
What do T cells (CTL or killer) do
Secrete toxic chemicals which destroy cells
Secrete substances which can enhance the activities of other immune cells
What does the suppressor T cell do
Restrain cytoxic T cells and B cells
What do memory T cells do
Retrain ability to recognise previously encountered antigens
What is humoral immunity
Related to the production and secretion of specific antibodies into the circulation
Antibodies produced by b lymphocytes (b cells produced in bone marrow) attempt to destroy or neutralise antigen
What is humoral immunity effective against
Bacteria and viruses
What do B cells do (humoral immunity)
Carry surface antibodies which recognise specific antigens
What’s the first line of defence
Skin and mucous membranes (non specific)
What’s the second line of defence
Macrophages (inflammatory response) (non specific)
What’s the third like of defence
B and T cells (specific)
What is an antigen
The immune system recognises as a foreign invader in the body
What are antibiotics
Substances that can destroy bacteria
What are antibodies
Proteins (Y shape) with constant and variable regions
Have an antigen binding area where they bind a specific antigen
What are the proteins called in antibodies
Immunoglobulins
How are antibodies produced and secreted
By the plasma cells from a B cell in response to the presence of an antigen
How is the immune response initiated
Antigens are presented to T cells
What do phagocytes do
Secrete chemicals to stimulate and activate T cells and B cells
What is the primary immune response
Involves initiation of antibody production
What is the secondary immune response
Enables a rapid and strong response to a pre encountered antigen
This memory is the basis of immunity to subsequent infections or bacteria and viruses
What does secondary exposure to antigen lead to
Rapid antibody production by B cells
What is immunisation
Vaccination protection against major bacterial and viral diseases
Relies on memory of immune system
What is hypersensitivity reaction
Exaggerated immune response to a non harmful antigen (allergy)
Inflammatory response
What is autoimmunity
Attack of self antigens by immune system
What is produces in autoimmunity
Autoantibodies and cytoxic T cells
