Basic concepts and Blood I Flashcards
1
Q
WHAT IS INTRAVENOUS (IV) GLUCOSE?
A
- Intravenously administered to maintain blood
glucose
2
Q
What is glucose?
A
- also known as dextrose
- a monosaccharide
- an aldohexose
- usually found in the form of a pyranose ring
- the ‘blood sugar’
- a reducing sugar ( Benedicts test positive)
3
Q
WHAT IS LUNG SURFACTANT?
A
- an extracellular fluid layer lining the alveoli of
lungs - Is secreted by type 2 granular pneumocytes,
composed of dipalmitoyl lecithin (major
component), phosphatidylglycerol and surfactant
proteins. - It decreases the surface tension in the alveoli,
reduces the pressure needed to reinflate the
alveoli thereby preventing alveolar collapse. - Deficiency of surfactant causes respiratory
distress syndrome [RDS or hyaline membrane
disease]. Premature infants have a higher
incidence of RDS. - Natural or synthetic surfactant can be
administered intratracheally to infants to treat
RDS - RDS due to insufficient amount of surfactant
can also occur in adults whose surfactant
producing pneumocytes have been damaged by
infection or trauma
4
Q
WHAT IS PLASMA?
A
- Plasma is obtained when blood is withdrawn into
a tube containing anticoagulant - Plasma is separated from the blood cells by
centrifugation of blood
5
Q
WHAT IS SERUM?
A
- When blood is allowed to clot, the clear liquid that
separates from the clot is serum - Plasma is used for glucose estimation
- Serum is used for the estimation of proteins,
electrolytes, enzymes and for electrophoresis
6
Q
A
- It is a process of protein separation based on
their electrical charges, and is usually
performed by applying a small amount of
serum to a strip of cellulose acetate or
agarose gel spread on a glass slide and
passing a current across it for a standard
time. - In this way five main groups of proteins,
albumin, α1-, α2-, β- and γ-globulins, may be
distinguished after staining and may be
visually compared with those in a normal
control serum. Each of the globulin fractions
contains several proteins. - The following description applies to the normal
appearance of the principal bands seen after
electrophoresis of serum on agarose gel
7
Q
ELECTROPHORESIS SLIDES:
4A. NORMAL SERUM
A
- Albumin, usually a single protein, makes up the
most obvious band; - α1-globulins consist almost entirely of α1-antitrypsin;
(α1 band) - α2-globulins consist mainly of α2-macroglobulins
and haptoglobin; (α2 band) - β- globulins consist mainly of transferrin; (β- band)
- γ-globulins are immunoglobulins; ( γ band)
8
Q
ELECTROPHORESIS SLIDES:
4B. NORMAL SERUM AND PLASMA
A
- If plasma is used for electrophoresis fibrinogen appears as a distinct
band in the β-γ region
9
Q
The serum electrophoretic patterns for some disorders are as follows:
4C. Nephrotic syndrome
A
- Thin albumin band (due to loss of albumin in urine because of increased
permeability of glomerular membrane) - Prominent α2 band (due to an increase in the levels of α2-macroglobulins)
10
Q
Cirrhosis of the liver
A
- Thin albumin band (decreased production of albumin by the damaged liver)
- β-γ bridging (due to markedly raised levels of γ-globulins)
11
Q
4E. Multiple myeloma
A
- Is a condition of malignant proliferation of plasma cells (B-lymphocytes)
characterized by disordered synthesis and secretion of immunoglobulins. - These cells synthesize and secrete only the monoclonal immunoglobulins
in excess. - An abnormal, dense band is seen in the γ-region (M-band) due to the
presence of myeloma protein in plasma which is a monoclonal
immunoglobulin.
12
Q
FIVE TYPES OF VACUTAINERS
A
- These are tubes for blood sample collection
designed to fill with a predetermined
volume of blood by vacuum - The tubes may contain additional
substances like anticoagulants, clot activators
or gel that preserve the blood for processing
in the clinical laboratory - The tubes are covered with a color-coded
plastic cap
*Color of the cap indicates which additives
that tube contains, hence each tube is unique
in terms of its contents and the test for which
it is used - However, the meaning of different colors
are standardized by different companies - Hence using the wrong tube for a particular
test makes the blood sample unusable
13
Q
Fluoride vacutainer (Grey)
A
- Used for collection of blood sample for glucose
determination - Contains Fluoride and EDTA (Ethylene
diaminetetraacetic acid) as additives - EDTA chelates Ca2+ present in the blood and
prevents blood coagulation
14
Q
Fluoride vacutainer (Grey)
A
Fluoride inhibits the glycolytic enzyme enolase non-competitively
↓
Inhibits the conversion of 2-phosphoglycerate to phosphoenolpyruvate
↓
Blocks glycolysis in RBCs
↓
Helps in accurate measurement of plasma glucose level
↓
If fluoride is not used, RBCs will use up glucose in vitro leading to a false
low value of plasma glucose
15
Q
Heparinized vacutainer (Green)
A
- Contains heparin as anticoagulant
- Used to obtain plasma for tests like liver function tests,
cardiac enzyme markers, lipid profile and determination
of metal ions - Also used to separate RBCs from blood for the
determination of glucose-6-phosphate dehydrogenase
activity - Heparinized tubes are preferred for plasma ion
estimations because unlike EDTA, it does not chelate ions
