blood Flashcards
what can blood be described as when the clotting factors have been removed
blood serum
what are the 2 parts of blood
cells
matrix = plasma
what are the 3 functions of the blood
1) transports - oxygen, co2, h2o, wbc’s, waste products, hormones
2) protects - clotting, immunity, defense, inflammation
3) regulates - fluid, PH, temperature, hormones
what are the 3 properties of blood
1) viscosity (resistance to flow) e.g thick
2) osmolality (concentration)
3) volume e.g high volume = high BP
how much blood do adults have on average and what percentage is made up of cells and plasma
4-6L
plasma (55%)
cells (45%)
what separates cells from plasma
centrifuge
what is haematocrit volume and what is the average
% of total volume of cells in the blood - normally 40-45%
also known as packed cell volume Packed Cell Volume
what is blood plasma made up of
nutrients, gases, electrolytes (eg Na+), hormones, plasma proteins, organic waste products (e.g urea, creatinine, uric acid which are all breakdown products removed by the kidney)
what are the 3 plasma proteins
1) albumin - most abundant, produced by the liver and influences blood pressure, flow and fluid balance
2) fibrinogen and clotting factors - produced by liver
3) globulins - produced by plasma cells for immunity
how many RBS are there for every WBC
700
what is the alternative name for RBC’s
erythrocytes
what are erythrocytes responsible for
gas transport (co2 and o2)
what does haemoglobin do
caries oxygen molecules in the blood
what is the acid that haemoglobin produces and what is it used for
carbonic acid
co2 + water ↔ H2CO3
Carbonic acid is an intermediate step in the transport of CO2 out of the body via respiratory gas exchange.
what is the life span of an erythrocyte
120 days
what is the carbonic acid equasion
carbonic acid
co2 + water ↔ H2CO3
what are platelets made up of and what do they do - 6 things
small fragments of megakaryocyte. secrete chemicals: clotting factors. vasoconstriction form temporary platelet plug dissolve old blood clots attract wbc's to sites of inflammation in order to phagocytose bacteria
what is a megakaryocyte
is a large bone marrow cell with a lobulated nucleus
what does stasis mean
stop
what is haemostasis
a balanced interaction of blood cells, vasculature, plasma proteins and low molecular weight substances
perfect haemostasis means no bleeding and no thrombis
what is primary haemostasis
temporary platelet plug
what is secondary haemostasis
coagulation - stable clot
what is the first thing to happen if a blood vessel is broken (2 things)
1) vascular spasm (constriction) caused by injury to smooth muscle
2) platelets release chemical serotonin
This provides time for the other 2 mechanisms to work
what happens once constriction of the broken blood vessel has occurred
platelet plug formation (platelet adhesion takes seconds, platelet aggregation takes minute)
POSITIVE FEEDBACK cycle!!
what is thrombin and what does it do
a clotting factor which converts soluble fibrinogen to insoluble fibrin which forms a tight mesh for RBC’s to stick to
Calcium is needed for this process!
what is extrinsic pathway
rapidly activated following tissues damage (seconds).
tissue releases chemicals called thromboplastin which initiates coagulation - Released from TISSUE
what happens following platelet plug formation
Coagulation
clotting factors usually do nothing unless triggered to do so. once one activated then another - coagulation pathway
what is intrinsic factor
slower activation than extrinsic. (minutes)
triggered when blood comes into contact with the damaged blood vessel lining (endothelium) - Released from BLOOD
what does it mean if you have haemopholia
blood cannot clot
why does clotting eventually stop
platelets produce chemicals to inhibit clotting
other substances such as heparin inhibit it too
how does clot dissolve
Fibrinolysis
plasmin (a fibrin dissolving enzyme) dissolves the clot
what is the most abundant plasma protein
albumin
what is the most common wbc
neutrophil
which wbc’s increase in number if there is an infection
eosinophils
which type of wbc’s increase if c.pox or sinusitis, diabetes
basophils
what is hypoxia and how does the body overcome it
hypoxia is lack of oxygen which is detected by chemoreceptors in the carotid body. this triggers the kidneys to produce EPO (erythropoietin) which stimulates the bone marrow to produce more rbc’s
what is anemia and what is it caused by
lack of red blood cells from blood loss or lack of iron (microcytic) or folic acid, Vit B12 (macrocytic)
what does aplastic mean
problem with bone marrow - failure of haemopoiesis
is fibrin a clotting factor
Yes
what determines the blood group
the antigen
what is cross matching
Cross-matching (or crossmatching) blood refers to the testing that is performed prior to a blood transfusion in order to determine if the donor’s blood is compatible with the blood of an intended recipient, or to identify matches for organ transplants.
how is mean cell haemoglobin calculated
haemoglobin concentration (g/l) of whole blood/red blood cell count
arteriole baroreceptors
are sensors located in the blood vessels which detect change from the usual mean arterial blood pressure, returning the pressure toward a normal
cardiac output is determined by
HR x Stroke Volume (the volume of blood ejected by the heart each minute)
In blood grouping, blood group A will produce ?
Anti B antibodies
what does the left ventricle of the heart do
ejects blood into the aorta which carries oxygenated blood from the left side of the heart to the system circulation
on and ECG (electrocardiogram) recording of the electrical activity of the heart, what happens to atrial repolarisation
atrial repolarisation of masked by ventricular depolarisation
An increase in mean arterial blood pressure may result from
an increase in cardiac output
what is the normal BP for a healthy 26 year old male
120/80
what is the normal rbc count
4.5-6.6 x 1012/L
what is normal mean cell value (average red blood cell volume of 1 rbc)
78-100 femtolitres
when is contraction of the heart more forceful
in the presence of adrenaline/nor adrenaline
what is the difference between adrenaline and noradrenaline
Adrenaline is mainly a hormone while noradrenaline is mainly a neurotransmitter.
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