red blood cells & white blood cells Flashcards
what are the 2 components of blood
cellular component - red cells, white cells, platelets
fluid component - plasma
how much of blood is made from cellular component
45%
how much of blood is made from fluid component
55%
how many litres of blood do we have
5
define haematocrit
the volume of red blood cells in your blood i.e haemoglobin in the blood, normal haematocrit is 0.45
what are 3 sites of haemolysis
- spleen
- bone marrow
- lymph nodes
what causes high haematocrit
excessive RBC production (polycythemia) and dehydration (plasma loss)
what causes low haematocrit
anaemia
what is normal haematocrit level
0.45
define haemopoiesis
the process of the production of blood cells and platelets which continues throughout life
what is difference between haemopoiesis location in adults and embryonic life and early infancy
adults occurs in bone marrow only
embryonic life and early infancy can occur in other sites as well
what are the most primitive types of cells
stem cells
what are pluripotent stem cells
can differentiate into red
blood cells, white blood cells and platelets
in the bone marrow the stem cells proliferate (reproduce rapidly) and differentiate into mature cells
what is the lifetime of red blood cells
120 days (make 2 million a second)
longest living cell other than red blood cells
what is the lifetime of platelets
7-10 days
what is the lifetime of white blood cells
6 hours
do red blood cells and platelets have a nucleus
no
they are anucleate
where are the precursor cells of red blood cells found (general)
red bone marrow of long bones (femur) in adults
where are the precursor cells of red blood cells found in adults
axial skeleton - skull, ribs, spine, pelvis and long bones
where are the precursor cells of red blood cells found in children
all bones
where are the precursor cells of red blood cells found in utero
yolk sac, then liver and spleen
what does it mean if precursor cells are found in blood
it is a sign of leukaemia
what do hormonal growth factors do
stimulate precursor stem cells to proliferate and differentiate
what is the hormonal growth factor for red blood cells and where is it made
Epo/ Erythropoietin
kidney
what is the hormonal growth factor for white blood cells
G-CSF (granulocyte colony stimulating factor)
why do red blood cells have a short lifespan
- simple cells
- with no nucleus or
mitochondria - so can’t repair themselves
what causes the oxygen disassociation curve to shift to right
when pH is decreased
OR
when temperature is increased
what causes the oxygen disassociation curve to shift to left
when pH is increased
OR
when temperature is decreased
what do you call a young red blood cell
reticulocyte
what do red blood cells consist of
- membrane to enclose Haemoglobin, otherwise the haemoglobin would
clog up the kidneys if allowed into the blood on its own - enzymes of glycolysis
- Haemoglobin - to carry oxygen
role of haemoglobin
Carries oxygen from the lungs to tissues, where it transfers oxygen to myoglobin in
muscles
structure of haemoglobin
2 alpha and 2 beta chains and 4 haem groups -
has an overall quaternary structures - due to the combination of more than two tertiary structures
how does oxygen bind to haem
oxygen binds to the Fe 2+ in haem
REVERSIBLY
SO
each haemoglobin molecule can carry up to four oxygen molecules
why is haemoglobin an allosteric protein
because the binding of oxygen to one haem group increases the oxygen affinity within the remaining haem groups.
when were red blood cells discovered
1658
function of red blood cells
carry oxygen to tissues
remove carbon dioxide from body
size of red blood cells
6.2-8.2 x 2 - 2.5 um
what causes anaemia
reduction of red blood cells or haemoglobin concentration in blood
causes of anaemia
- impaired production
- increased haemolysis
what is the normal haemoglobin level
12.5 - 15.5 g/dl
what causes polycythaemia
increase of haemoglobin in blood
causes of polycythaemia
smoking, lung diseases, inefficient lungs
meaning less O2 is exchanged so more haemoglobin is required
symptoms of anaemia
tiredness
lethargy
malaise
reduced exercise tolerance
shortness of breath on exertion
angina
what are the signs to look for in anaemia
Palor
pale mucus membranes and palmar creases (pink hands)
glossitis
(sore tongue)
angular stomatitis ( cracking at corners of mouth)
kylonychia (caused
by the iron deficiency - spoon shaped nails)
what are the different classifications of anaemia
- Iron deficiency
- B12/folate deficiency
- anaemia of chronic disorder
- haemolysis
- bone marrow failure/infiltration
what is iron deficiency anaemia
iron is needed for haemoglobin production,
lack of iron results in the reduced production of small red cells
causes low haemoglobin and MCV < 80 fl
what is the size of red blood cells in iron deficiency anaemia
less than 80 fl
how do you measure red cell size
MCV (mean cell volume), normal = 82 - 96 fl
causes of iron deficiency anaemia
Bleeding:
* Occult gastrointestinal: can affect anyone, most common cause of iron deficiency anaemia
* Menorrhagia (heavy periods): Occurs in premenopausal women only or those
who’ve have repeated child birth
- Dietary:
- Not getting enough iron in diet, in the UK the cause is never diet
- Worldwide the most common cause of iron deficiency anaemia is diet
what is macrocytic anaemia
a blood disorder that happens when your bone marrow produces abnormally large red blood cells.
the red blood cells are = > 100 fl
what is macrocytic anaemia
a blood disorder that happens when your bone marrow produces abnormally large red blood cells.
what is the size of red blood cells in macrocytosis anaemia
bigger than 100 fl
can macrocytosis occur without anaemia
yes
there will be a raised MCV but normal
haemoglobin levels
can be caused by liver disease, alcohol and hypothyroidism
what causes macrocytic anaemia
a deficiency of vitamin B12 or folate
- VITAMIN B12 & FOLATE ARE NEEDED FOR DNA SYNTHESIS
- so with a B12 & folate deficiency red blood cells cannot by made in the bone marrow and thus less are released = ANAEMIA.
- This deficiency will affect all dividing cells, but bone marrow is most active so is affected first
causes of B12 deficiency
- damaged stomach affecting intrinsic factor
- an autoimmune disease called pernicious anaemia
how does damaged stomach affecting intrinsic factor cause B12 deficienc
- In the terminal ileum(last part of the small intestine) B12 absorption occurs
- however intrinsic factor PRODUCED
BY THE GASTRIC PARIETAL CELLS IN THE STOMACH is required for absorption to occur since B12 binds to intrinsic factor and is THEN absorbed. - Thus if the stomach is damaged can result in less parietal cells
- thus less intrinsic factor
- thus less B12 absorbed thus anaemia
what is intrinsic factor
a protein that helps your intestines absorb vitamin B12.
It is made by cells in the stomach lining
how does pernicious anaemia cause B12 deficiency
- causes the antibodies to be made against gastric parietal cells meaning less intrinsic factor can be produced
- so there is B12 malabsorption and thus ANAEMIA.
- However the liver has a vast store of B12 which can last 4 years, thus pernicious anaemia has a slow onset
where is folate found
fruit and veg
causes of folate deficiency
malabsorption - eg due to celiac disease
dietary - not eating enough fruit and veg
anything that results in increased cell
division can cause a folate deficiency
what is haemolysis
the destruction or rupture of red blood cells before their 120 day lifespan
what are congenital haemolytic anaemias
they are present from birth
can have:
- membrane issues
- enzyme issues
- haemoglobin issues
example of membrane issue congenital disease
SPHEROCYTOSIS
whereby blood cells are spherical, they
get stuck in vessels easily,
DOMINANT CONDITION BUT VARIABLE
PENETRANCE
example of enzyme issue congenital disease
PYRUVATE KINASE DEFICIENCY
enzyme required to convert
phosphoenolpyruvate to pyruvate is deficient
resulting is less ATP production and
also a build up of phosphoenolpyruvate, or G6PD DEFICIENCY
2 examples of haemoglobin issue congenital disease
SICKLE CELL ANAEMIA (defect in beta globin chain in haemoglobin) - whereby red blood cells are sickle shaped thus get trapped in vessels
easily
THALASSAEMIA - mutation in haemoglobin chains, beta is more common in india + Pakistan whereas alpha is more common in east e.g. Thailand
2 examples of haemoglobin issue congenital disease
SICKLE CELL ANAEMIA (defect in beta globin chain in haemoglobin) - whereby red blood cells are sickle shaped thus get trapped in vessels
easily
THALASSAEMIA - mutation in haemoglobin chains, beta is more common in india + Pakistan whereas alpha is more common in east e.g. Thailand
2 examples of haemoglobin issue congenital disease
SICKLE CELL ANAEMIA (defect in beta globin chain in haemoglobin) - whereby red blood cells are sickle shaped thus get trapped in vessels
easily
THALASSAEMIA - mutation in haemoglobin chains, beta is more common in india + Pakistan whereas alpha is more common in east e.g. Thailand
what are acquired haemolytic anaemias
- autoimmune
- mechanical
- pregnancy
what causes autoimmune-acquired haemolytic anaemias
immune system attacks own red blood cells, can be triggered by a
blood transfusion due to the presence of foreign antibodies
what causes mechanical acquired haemolytic anaemias
fragmentation of red blood cells by mechanical heart valve
or
intravascular thrombosis in DIC (disseminate intravascular coagulation)
what causes acquired haemolytic anaemias in pregnancy
HAEMOLYTIC DISEASE OF THE FOETUS & NEWBORN [HDFN]:
- Mother has Rhesus NEGATIVE blood (RhD negative) and baby has Rhesus
POSITIVE blood (RhD positive). - When mothers blood is exposed to babies blood in pregnancy for example, mothers immune system recognises foreign Rhesus positive blood and begins making antibodies against babies blood - 3. FIRST baby is unaffected since it takes time for antibodies to be produced, the mother is said to be SENSITISED to Rhesus positive blood
- However, if mothers second baby also has RhD positive blood, then when mothers blood is exposed to babies, antibodies are produced IMMEDIATELY and begin DESTROYING BABIES RED BLOOD CELLS
- resulting in HAEMOLYSIS OF
FOETUS/NEWBORN = ANAEMIA AND JAUNDICE. - Whilst mother is carrying the
baby, her antibodies can cross to baby via the placenta and begin attacking -
THIS IS KNOWN AS RHESUS DISEASE
another name for white blood cells
leukocytes
where are leukocytes found
blood and lymph tissue
describe the divination of white blood cells
leukocytes –> agranulocytes & granulocytes
agranulocytes –> monocytes & lymphocytes
granulocytes –> basophils & eosinophils & neutrophils
what are granulocytes
a type of white blood cell that has small granules.
These granules contain proteins.
3 types:
neutrophils, eosinophils, and basophils
what are white blood cells produced from
from immature precursor cells in the bone marrow which are derived
from stem cells.
rate of production of white blood cells
Rate of production is under hormonal control of G-CSF
what are neutrophils
most numerous white cell
act as first line of defence during acute inflammation
do phagocytosis
what do neutrophils do
- Phagocytose & kill bacteria
- Release chemotaxins (signal more white blood cells to come to site) and cytokines -important in inflammatory response
- Lack of number or function results in recurrent bacterial infections
what do eosinophils do
- combats parasite infections
- neutralises histamine
what do basophils do
- responsible for anaphylaxis
- produces histamine
what are agranulocytes
white blood cells that have no distinct granules in their cytoplasm
2 types:
monocytes & lymphocytes
what do monocytes do
largest WBC
when in blood they exist as monocytes
when in tissue they differentiate into macrophages and carry out phagocytosis of foreign material
4 examples of monocytes
- Kupffer cells (Liver)
- Microglial cells (CNS)
- Alveolar macrophages (Lungs)
- Tissue macrophages (everywhere)
what are lymphocytes
3 types
- B cells
- T cells
- natural killer cells
they are vital to immunity
- Some generate antibodies against specific foreign antigens e.g bacteria & viruses
- Others are immunological memory - which generates immunity and allows
vaccination
what are B lymphocytes
named after Bone marrow, made in bone marrow - stored in secondary lymphoid organs
differentiate into plasma cells and produced immunoglobulins (antibodies) when stimulated by exposure to foreign antigen
what are T lymphocytes
made in bone marrow - MATURE in thymus, some are helper
cells (CD4, help B cells in antibody generation, responsible for cellular or cell
mediated immunity), some are cytotoxic cells (CD8)
what do natural killer cells do
kill virus-infected cells
what is acute leukaemia
Proliferation (rapid increase) of primitive precursor cells usually found in bone
marrow - too many white cells
proliferation WITHOUT differentiation, replaces NORMAL BONE MARROW CELLS - resulting in anaemia (palor and lethargy), neutropenia and thrombocytopenia
THE PRESENCE OF PRIMITIVE WHITE PRECURSOR CELLS
IN THE BLOOD IS A SIGN OF acute leukaemia
what is neutropenia
when you dont have enough neutrophils in blood
what is thrombocytopenia:
when you dont have enough platelets in blood - leads to excessive bleeding
what is - Acute myeloblastic leukaemia (AML):
Malignant proliferation of the precursor
myeloblasts (unipotent stem cells) in the bone marrow, disease primarily affects
adults - 50% survive 5 years
what is - Acute lymphocytic leukaemia (ALL):
Malignant proliferation of the lymphoblast
precursor cells in the bone marrow, disease primarily affects children - 80% cured
what is High grade lymphoma
( lymphocytes in lymph nodes becoming malignant, very
similar to leukaemia): Classified as Hodgkins disease and Non-Hodgkins
lymphoma (NHL), disease usually of the lymph nodes that spreads to the
liver,spleen, bone marrow and blood
what is innate immunity
body’s first line of defence against pathogens. It is general and non-specific, which means it does not differentiate between types of pathogens
what is adaptive immunity
a type of immunity that is built up as we are exposed to diseases or get vaccinated
what is humoral immunity
secrete antigen specific antibodies that defend against extracellular pathogens
primarily driven by B cells
what is cell mediated immunity
primarily driven by mature T cells, macrophages and the release of cytokines in response to an antigen
defend against infected cells, cancers and transplant tissues
what is another name for a red blood cell
erythrocyte
impact of RBC bioconcave shape
increased SA –> better gas exchange
impact of RBC being anucleate
more room for haemoglobin
