Post on 02-Dec-2021
ONE TWO THREE FOUR
Mastering Medical
Terminology
Essential of Human
Anatomy and Physiology
Mosby’s Dictionary KENHUB
By Sue Walker, Maryann Wood
and Jenny Nicol
By Elaine Marieb and Suzanne
Keller
By Mosby www.kenhub.com
Introduction
3Khaleel Alyahya, PhD, MEd
▪ Although there are many blood group systems with
several subtypes, the two best-known ways of classifying
blood are the ABO group system and the Rhesus (Rh) type
system.
▪ In the former, there are four main blood groups, known as
types A, B, AB and O which are identified based on
combinations of inherited antigens and antibodies present on
the surface of red blood cells.
History
4Khaleel Alyahya, PhD, MEd
▪ The ABO blood group system was first identified by an Austrian
scientist Dr Landsteiner in 1901.
▪ Dr Landsteiner recognized the reactions between the blood antigens
and certain antibodies in the plasma that caused the blood serum of
some people to clump the blood of others.
▪ After further experimentation, he formally identified the four mutually
incompatible blood groups (A, B, AB, O) based on the presence or
absence of the two specific antigens, A and B.
▪ Later in his career Landsteiner identified the Rhesus factor.
ABO System
5Khaleel Alyahya, PhD, MEd
▪ These blood types are determined by the absence of a particular
antigen corresponding to the presence of an antibody for that antigen.
Therefor:
▪ If a person is blood group A, they will have A antigens on their red
blood cells and antibodies to antigen B in their plasma.
▪ If the individual is blood group B, they will have B antigens on their
red blood cells and antibodies to antigen A in their plasma.
▪ People who have blood type AB have both A and B antigens on their
red blood cells, so do not have antibodies to either A or B in their
plasma.
▪ Individuals with blood type O have no A or B antigens but have
antibodies to both A and B in their plasma, thus, this type of blood can
give blood to any other types.
Rhesus Factor
6Khaleel Alyahya, PhD, MEd
▪ Blood type is also determined by a pair of inherited genes known as
the Rhesus (Rh) factor.
▪ Rhesus factor, or Rh factor as it is also called, was first identified in
the blood of Rhesus monkeys.
▪ These small monkeys were often used for medical
experimentation.
▪ A person is either Rh-positive or Rh-negative, depending on the
presence or absence of the inherited Rhesus protein in their red blood
cells.
▪ A person who is Rh-negative will experience a severe immune
system reaction if Rh-positive blood gets into their bloodstream
because the body creates antibodies against the foreign protein.
▪ This can occur during a mismatched transfusion or through the
placenta during a second or subsequent pregnancy where the
mother is Rh-negative, and the baby inherits Rh-positive blood from
its father.
Blood Transfusion
7Khaleel Alyahya, PhD, MEd
▪ A blood transfusion is the transfer of blood or blood products from adonor to a recipient.
▪ It may be given to replace the blood of a patient followinghaemorrhage, surgery, injury or certain illnesses such as anaemia.
▪ The blood used in a transfusion must be compatible with the bloodtype of the recipient; otherwise, an antibody reaction calledagglutination will result.
▪ It is always preferable for patients to be transfused with blood of thesame ABO and Rh groups as they have themselves.
▪ If a person undergoing transfusion of blood has a blood group thatdoes not have any antibodies against the antigens present in thedonor blood, all will be well.
▪ However, if the recipient’s blood has antibodies which match theantigens in the donated blood, agglutination or binding of the redblood cells in the donated blood will occur.
▪ In an emergency, however, if the required blood group is notavailable, it is possible for a patient to be given a different group asfollows.
Donors
8Khaleel Alyahya, PhD, MEd
▪ A person with type O blood is known as the universal donor
because type O blood can be given to a person with any blood type.
However, a person with type O blood can only receive type O blood.
▪ A person with type AB blood is known as the universal recipient
because they can receive type A, B, AB or O blood.
▪ A person with type A blood can receive a transfusion of types A and
O blood.
▪ For a type B recipient, the blood transfusion must be type B or type
O.
▪ However, the Rh factor must always be compatible between the
donor and the recipient.
▪ A blood transfusion may consist of ‘whole blood’, containing both the
plasma and cellular components of blood, or only the red cells known
as packed cells.
▪ This type of transfusion is normally given to a patient who is lacking
red blood cells because of anaemia.
Blood Analysis
9Khaleel Alyahya, PhD, MEd
▪ Haematology is a general term for the study of blood.
▪ Within the specialty of haematology, there are several different
categories of blood tests that may be performed by a laboratory.
▪ All tests compare a patient’s results against a ‘reference range’.
▪ The reference range represents the average value for a ‘normal’
population group, generally with any expected variation that may be
seen (usually plus or minus 2 standard deviations from the average).
▪ Reference ranges are set by the laboratory that provides the test
results, and different laboratories use varying equipment and testing
methods.
▪ That means each laboratory has its own references ranges, and
these may differ from laboratory to laboratory.
▪ Therefore, results from one laboratory cannot always be compared
with those from another laboratory.
▪ See page 539 for examples of standard haematological values.
Transfusion Reactions
10Khaleel Alyahya, PhD, MEd
▪ Transfusion reactions occur when mismatched blood is infused.
▪ Donor’s cells are attacked by the recipient’s plasma antibodies
causing:
• Diminished oxygen-carrying capacity.
• Clumped cells that impede blood flow.
• Ruptured RBCs that release free hemoglobin into the bloodstream.
▪ Circulating hemoglobin precipitates in the kidneys and causes renal
failure.
Blood Types & Reactions
11Khaleel Alyahya, PhD, MEd
Blood Type Testing
12Khaleel Alyahya, PhD, MEd
Rh Factors & Pregnancy
13Khaleel Alyahya, PhD, MEd
Blood Tests
Haematology
15Khaleel Alyahya, PhD, MEd
▪ Haematology specifically looks at blood and bone marrow to
identify cancers of the blood (such as leukaemia and
lymphoma) and clotting disorders.
▪ Blood grouping and antibody testing for blood banking is also
done by haematology as is the most commonly ordered test —
a full blood count.
Biochemistry
16Khaleel Alyahya, PhD, MEd
▪ Biochemistry assesses the levels of chemicals in the body to
determine if a disease is present or not.
▪ Biochemistry tests include electrolytes, liver function tests,
cholesterol, triglycerides, lipids, blood glucose and drug levels.
Cytogenetics
17Khaleel Alyahya, PhD, MEd
▪ This is a new area of study which examines genes and
chromosomes.
▪ It is concerned with genetic testing and cancer diagnosis.
▪ Cytogenetic tests can be performed on blood, bone marrow,
fetal specimens, and body tissues.
Microbiology
18Khaleel Alyahya, PhD, MEd
▪ Microbiology looks for infections such as viruses, bacteria,
parasites in blood as well as other body tissues.
Serology
19Khaleel Alyahya, PhD, MEd
▪ Serology examines blood serum for antibodies to specific
infections such as influenza, rubella, Epstein-Barr virus, Ross
River fever and to various allergens.
▪ By performing a serology test, it is possible to determine a
patient’s infection status or if they have responded to an
immunization.
Venepuncture
20Khaleel Alyahya, PhD, MEd
▪ Venepuncture is the process of obtaining intravenous access for the
purpose of intravenous therapy or for blood sampling of venous blood.
▪ In healthcare, this procedure is performed by medical laboratory
scientists, medical practitioners, and some other technicians and
nursing staff.
▪ It is essential to follow a standard procedure for the collection of blood
specimens to get accurate laboratory results.
▪ Any error in collecting the blood or filling the test tubes may lead to
erroneous laboratory results.