Blood Plasma Flashcards
What is plasma?
the liquid component of blood
- comprising around 55% of volume
What is blood made of?
plasma 55%
buffy coat <1%
red cells 45%
What is the buffy coat?
consists of leukocytes and platelets- roughly 1%
How is blood taken?
in a tube with anticoagulant
What is extracellular fluid?
Interstitial fluid + blood plasma + transcellular fluid
What are the four fluid compartments and their relative proportions?
Intracellular 55%/ 23L
Interstitial 36%/ 15L
Blood plasma 7%/ 3L
Transcellular 2%/ 1L
(these figures are typical, but vary between individuals)
What is serum?
plasma minus the clotting factors
How do you get serum?
blood is taken in a tube WITHOUT anticoagulant, allowed to clot, and then centrifuged
What do serum separator tubes have (SST)?
A silica coating which induces clotting
A layer of gel forming a physical barrier between cells and serum
What is quicker to prepare and which one gives a cleaner sample, out of serum and plasma?
plasma is relatively quick to prepare
serum is a cleaner sample but takes longer
What are the functions of plasma?
Clotting- clotting factors and von Willebrand factor
Immune defence- antibodies and complement proteins are found in plasma
Osmotic pressure maintenance- proteins such as albumin help to maintain colloidal osmotic pressure
Metabolism- nutrients such as glucose, amino acids, and vitamins are transported in the plasma
Endocrine- many hormones are soluble in plasma and following release into the blood travel to their target organs
Excretion- waste products of cell metabolism such as urea are transported via the plasma fraction of the blood to the kidneys for removal
How much of plasma is proteins?
7%
How can you assay the plasma proteins?
by electrophoresis
What are the 2 major plasma proteins?
albumins and globulins
What is the most abundant protein in the blood?
Serum albumin
Why does albumin have the biggest peak and closest to the left side?
Largest therefore closest to cathode
What are the types of gobulins in the blood?
alpha1, alpha2, beta1, beta2, gamma globulin
What ion has the highest concentration in plasma?
Sodium
What ion has the highest concentration in blood cells?
K+
Where is serum albumin produced?
by the liver
How much of plasma proteins are serum albumin?
around 55%
What are the functions of serum albumin?
Transport of lipids, hormones, and ions
Maintaining the osmotic pressure of plasma
What do serum albumin transport?
Fatty acids released by lipolysis from the breakdown of triglycerides in adipose tissue are transported by albumin for use by tissues for beta-oxidation
How much of plasma proteins are globulins?
around 35%
What is the alpha 1 globulin?
A1AT - Alpha 1 anti-trypsin
Where is alpha 1 anti-trypsin formed?
In the liver and then enters circulation
What does A1AT do?
It is a protease inhibitor, protects the lungs against degradation of tissue by neutrophil elastase
When is neutrophil elastase released?
Released by neutrophils during inflammation
What can happen if someone has defective/ deficient alpha 1 anti-trypsin?
It can compromise the lungs, where degradation of lung tissue leads to a loss of elasticity and respiratory problems
They become more vulnerable to inhaled pollutants e.g., smoke, dust
What are the alpha 2 globulins?
alpha2-Macroglobulin and haptoglobin
What does alpha2-macroglobulin do?
it is a broadly active protease inhibitor which can inactivate fibrinolysis (the breakdown of fibrin involved in blood clotting)
What does haptoglobin do?
It binds to haemoglobin released from erythrocytes and the resulting heptoglobin-haemoglobin complex is removed by the spleen
What can measuring the levels of heptoglobin inform you of?
it can be informative in the diagnosis of haemolytic anaemia in combination with other parameters
What are beta globulins?
Complement proteins (e.g., C3 and C4) and transferrin
What is the role of transferrin?
pays a role in the transportation of iron, it transports both dietary iron and the iron released from the stores of ferritin
Where is transferrin made?
The liver
What are Gamma globulins?
C Reactive protein - increased levels during infection / inflammation
Immunoglobulins (antibodies)
What are the diagnostic uses of measuring gamma globulins?
Increases in the relative amounts of the gamma fraction of globulins can indicate infection or myeloma
How much of plasma are electrolytes?
1%
What is the role of electrolytes?
contributors to osmolarity
How is the positive charge from intracellular potassium balanced?
by extracellular Cl-
- the internally high concentration of K+ inside the cell is also neutralised by a variety of anions e.g., proteins, nucleic acids, phosphorylated proteins
What are the electrolytes/ components in plasma/ blood cells?
Why is Mg2+ important?
an important cofactor for many enzymes
What is an increase in intracellular Ca2+ associated with?
signalling
What protein helps to maintain colloid osmotic pressure?
Serum albumin
More than one third of the ATP consumed during rest is used to do what?
Power the Na+/K+ ATPase
What happens to the shape of the cells when ATP levels depleted?
The cells have a tendency to become more spherical because of the inwards movement of sodium ions and water
What can plasma be used for?
biomarkers and passive immunotherapy
How can plasma be used for biomarkers?
Plasma and serum provide an easy to obtain clinical specimen that can be subjected to laboratory tests for diagnostic purposes
The study of the plasma proteome and links with disease, medications and lifestyle is useful to inform treatment decisions
Elevated levels of some key molecules provide handy biomarkers of disease
How can plasma be used in passive immunotherapy?
Immunoglobulins found in the gamma globulin fraction can be used to transfer immunity from one individual to another.
What is IVIG?
Intravenous Immunoglobulin - allows for the introduction of relatively large amounts of IgG
Protects against most of the common pathogens donors are exposed to e.g., measles, mumps, rubella
How are the IgG obtained from patients?
Donors are screen for high levels of IgG against a particular pathogen using ELISA, this IgG fraction is then isolated from the plasma of these donors and concentrated
What is a fault of passive immunotherapy?
Provides passive immunity to a specific pathogen
Often given following high risk exposure to a pathogen e.g. rabies, hepatitis b, varicella zoster
Vaccinations provide active immunity but required days/ weeks to elicit a response
What is convalescent plasma?
Plasma of patients who have recovered from different diseases like COVID19
How can convalescent plasma be used to treat patient with COVID19?
- Patients infected with SARS-CoV-2, develop antibodies against the virus.
- After the patient has recovered (convalesced), blood is donated to produce obtain antibody-rich plasma.
- The plasma is tested for strength (affinity) and number of antibodies.
- If these levels are fine, the plasma is given to a patient infected with COVID-19.
What is the main difference between plasma and interstitial fluid?
Plasma is very similar to interstitial with the main difference being that plasma contains much more protein.
How much of plasma proteins are serum albumin?
around 55%
How is the positive charge from intracellular potassium balanced?
by extracellular Cl-
- the internally high concentration of K+ inside the cell is also neutralised by a variety of anions e.g., proteins, nucleic acids, phosphorylated proteins
