Medical Terminology Chapter 3:
Bacteria, Blood cells and
Disorders of the blood
Blood Cells and Their Function
I. Erythrocytes (also called Red Blood
Cells)
– These cells are made in the bone
marrow and are necessary to carry
oxygen to the cells of the body.
– Oxygen is used up by the body cells in
the process of converting food to
energy (which is called?) and carbon
dioxide (a waste product of the cell) is
then carried to the lung for exhalation.
– Hemoglobin (Hemo=blood;
globin=protein) is a protein within the
RBC that carries (binds with) oxygen
through the blood stream.
II. Leukocytes: (also called white blood cells)
There are several types of White blood cells that fall into two
categories:
1. Granulocytes (3 types): Neutrophils, Eosinophils, and Basophils
2. Agranulocytes (2 types): Lymphocytes and Monocytes
A. Granulocytes: (contain granules that stain
dark in the cytoplasm)
1.Neutrophils: (polymorphonuclear) Contains granules
in cytoplasm. The nucleus is frequently multi-lobed
with lobes connected by thin strands of nuclear
material. These cells are capable of phagocytizing
(eat or engulf/swallowing) foreign cells, bacteria,
and viruses.
• When taking a Differential WBC Count of normal
blood, this type of cell would be the most
numerous. Normally, neutrophils account for
approx 60% of all leukocytes. If the count exceeds
this amount, the cause is usually due to infection.
Leukocytes Cont…
2.Eosinophil: Has large granules (A) which appear
pink (or eosin/o= rosy) in a stained preparation.
The nucleus often has two lobes connected by a
band of nuclear material. The granules contain
digestive enzymes that are particularly effective
against parasitic worms in their larval form. These
cells also phagocytize antigen-antibody complexes;
and are thought to be active and elevate in allergic
conditions such as asthma and food or insect
allergies. These cells make up approx 3% of the
leukocytes.
3. Basophils: These granules are large, stain deep
blue to purple, and generally so numerous they
mask the nucleus. These granules contain
histamines (that cause vasodilation) and heparin
(which is an anticoagulant).
In a Differential WBC Count they represent less
than 1% of all leukocytes. If the count showed an
abnormally increase in number; hemolytic anemia
or chicken pox may be the cause.
Leukocytes cont…
B. Agranulocytes: Do not contain granules
in the cytoplasm; and are produced in the
lymph nodes and spleen)
1.MONOCYTE
This cell is the largest of the leukocytes and is
agranular. The nucleus is most often "U" or kidney
bean shaped; the cytoplasm is light blue with no
granules. These cells leave the blood stream and
enter tissues to become macrophages. As a
monocyte or macrophage, these cells are
phagocytic and defend the body against viruses and
bacteria.
– These cells account for 4-9% of all leukocytes.
Leukocyte cont…
2. LYMPHOCYTE :
The lymphocyte is an agranular cell (Notice that
the nucleus almost fills the cell leaving a very
thin rim of cytoplasm.) This cell is much smaller
than the three granulocytes. The lymphocytes
play an important role in our immune response.
The T-lymphocytes act against virus infected
cells and tumor cells. The B-lymphocytes
produce antibodies.
• This is the 2nd most numerous leukocyte,
accounting for 32% of the cells in a Differential
WBC Count. When these cells exceed the normal
amount, one would suspect infectious
mononucleosis or a chronic infection. Patients
with AIDS keep a careful watch on their T-cell
levels as an indicator of the AIDS virus' activity.
Blood Cells cont…
III. Platelets (also called Thrombocytes):
are cell fragments, and are seen next to
the "t's" in the picture below. Platelets are
important for proper blood clotting (also
called coagulation).
• Each cubic millimeter of blood should
contain 250,000 to 500,000 of these. If
the number is too high, spontaneous
clotting may occur. If the number is too
low, clotting may not occur when
necessary.
What is Anemia?
• Anemia refers to a medical condition in which there is a
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reduction in the number of erythrocytes, or the amount of
hemoglobin in the circulating blood.
There are many different kinds of Anemia's:
Vitamin B-12- Your body needs vitamin B12 to make red blood cells. In order to
provide vitamin B12 to your cells you must eat enough foods that contain
vitamin B12, such as meat, poultry, shellfish, eggs, and dairy products.
Hemolytic- Hemolytic anemia is a condition in which there are not enough red
blood cells in the blood, due to the premature destruction of red blood cells.
Pernicious- Pernicious anemia is a decrease in red blood cells that occurs when
the body cannot properly absorb vitamin B12 from the gastrointestinal tract.
Vitamin B12 is necessary for the proper development of red blood cells.
Sickle cell- Sickle cell anemia is caused by an abnormal type of hemoglobin
called hemoglobin S. Hemoglobin S distorts the shape of red blood cells,
especially when exposed to low oxygen levels. The distorted red blood cells
are shaped like crescents or sickles. These fragile, sickle-shaped cells deliver
less oxygen to the body's tissues, clog more easily in small blood vessels,
and break into pieces that disrupt healthy blood flow. Sickle cell anemia is
inherited from both parents.
Anemia cont…
Aplastic anemia is a failure of the bone marrow to make
enough blood cells. All blood cell types are affected.
Aplastic anemia is generally caused by injury to blood
stem cells. Normal blood stem cells divide and turn into all
blood cell types, mainly white blood cells, red blood cells,
and platelets. When blood stem cells are injured, there is
a reduction in all blood cell types.
This condition can be caused by:
• Certain drugs
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Chemotherapy
Disorders present at birth (congenital disorders)
Drug therapy to suppress the immune system
Pregnancy
Radiation therapy
Toxins such as benzene or arsenic
Ischemia:
• Is an inadequate blood supply (or circulation) to a local area
of the body due to blockage of the blood vessels to the
area. It is generally caused by vasoconstriction (narrowing
of vessels), thrombosis (clots), embolism (fat, air or
bacterial clumps) or injury to a vessel. Many people have
ischemic episodes without knowing it.
• Some causes are:
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Sickle Cell Anemia
Compression of blood vessels
Ventricular Tachycardia
Plaque build-up in arteries (atherosclerosis)
Blood clots
Extremely low blood pressure as caused by heart attack
Congenital Heart Defects
Types of Bacteria
• Streptococcus: is a berry shaped bacterium that grows in twisted chains.
One group of strep can cause conditions such as Strep throat, tonsillitis,
and kidney disorders; and another types causes infections of the teeth,
sinuses, and valves in the heart.
• Staphylococci:
are spherical (round) bacteria that grow in bunches (like
grapes) This bacteria can cause lesions that are external such as: skin
abscesses, boils, and styes; or internally causing abscesses in the bone and
kidney. A White blood cell moves through the walls of the blood vessels into the
area of the infection and collects within the damaged tissue. During this process, pus
forms. Pus is the buildup of fluid, living and dead white blood cells, dead tissue, and
bacteria or other foreign substances.
• Diplococci:
are spherical bacteria arranged in pairs. This bacteria is the most
common cause of bacterial pneumonia in adults and a STD called gonorrhea
(gonococci) in the reproductive system.
Leukocytosis:
• Leukocytosis is a condition characterized by an
elevated number of white cells in the blood.
What causes leukocytosis?
• Infection: An infection may be caused by germs called bacteria, virus or
a parasite.
• Inflammation: (swelling, pain, and redness) an example is Arthritis;
which is an inflammation of the joints.
• Tissue damage: You may get leukocytosis from burns and some diseases
that cause tissue damage such as cancer and heart disease.
• Immune reactions: Leukocytosis may occur when your immune system
reacts too strongly to a foreign substance.
• Bone marrow problems: You may get leukocytosis if your bone marrow
makes too many WBCs.
• Medicine: Some medicines may cause leukocytosis.
• Stress: You may get leukocytosis if you have a lot of emotional and
physical stress.
Spleenomegaly
• The spleen is a small organ located just below your rib cage on your left
side. It filters blood and removes old and damaged red blood cells, bacteria, and
other particles as they pass through the blood vessels within the spleen.
• It produces lymphocytes and assists the immune system. It also disposes of dying
RBC’s and manufactures WBC’s (lymphocytes) to fight disease. Normally, your
spleen is about the size of a fist, but a number of conditions can cause
spleenomegaly; such Various Infections (including Bacterial, viral and
Parasitic infections), Diseases of the liver, Blood diseases, and Cancer
Tonsillitis:
• Tonsils are made of soft glandular tissue and are part of the
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immune system. They are the two bumps or mounds of tissue
located in the back of the throat, and are made up of what is
called lymphoid tissue.
Lymphoid tissue produces lymphocytes; white blood cells that
help to filter and fight bacteria and viruses which you may
ingest or breathe in. Antibodies and immune cells in the tonsils
help to kill germs and help to prevent throat and lung
infections.
Streptococcal infections can sometimes cause them to become
infected and inflamed
Amniocentesis
• Amniocentesis is a procedure that is carried out during
pregnancy, usually to diagnose various chromosome or genetic
conditions in the unborn, developing baby. A sample of the
amniotic fluid inside your uterus (womb) that is surrounding the
baby is taken using a fine needle. Tests are done on the fluid in
the laboratory. Amniocentesis is offered after 12 completed
weeks of pregnancy (usually between 15-18 weeks). The most
common reason for a pregnant woman to be offered
amniocentesis is to see if their developing baby has a
chromosome disorder such as Down's syndrome. There is a
small risk of complications with amniocentesis, including
miscarriage.
What is a Hernia????????
• A Hernia occurs when the contents of a body cavity bulge out of the area
where they are normally contained. In this condition, a weak spot or
opening in a body wall, often due to laxity of the muscles, allows part of the
organ to protrude.
Hiatal hernia is a condition in which the upper portion of the
stomach protrudes into the chest cavity through an opening of the
diaphragm called the esophageal hiatus
Inguinal hernia: occurs when part of the intestines or tissues pushes
through a weak spot in your groin muscle. This causes a bulge in the groin
region or scrotum
Rectocele: also called a vaginal hernia. This is a bulge of the front wall
of the rectum into the vagina. The rectum is the last part of the large
bowel (colon) where stool is stored for a short time. In women, the
rectum is just behind the vagina.
Omphalocele (or Umbilical Hernia): due to an imperfect closure or
weakness of the umbilical ring in infants . It appears as a skin-covered
protrusion at the UMBILICUS during crying, coughing, or straining.
Cystocele: occurs when the wall between a woman’s bladder and
her vagina weakens and allows the bladder to droop into the
vagina. This may cause problems with emptying the bladder; and most
often a result from muscle straining while giving birth.
What is Achondroplasia?
• Achondroplasia is a genetic (inherited) condition that
results in abnormally short stature and is the most
common cause of short stature with disproportionately
short limbs. The average height of an adult with
achondroplasia is 131 cm (52 inches, or 4 foot 4 inches)
in males and 124 cm (49 inches, or 4 foot 1 inch) in
females.
• Although achondroplasia literally means "without
cartilage formation, the defect is not in forming cartilage
but in converting it to bone, particularly in the long
bones.
• Achondroplasia is one of the oldest known birth defects.
The frequency is an average figure worldwide is
approximately 1 in 25,000 births.
Blepharoptosis
• Blepharoptosis, also referred to as ptosis,
is defined as an abnormal low-lying upper
eyelid margin with the eye in primary
gaze.
Laparoscopy
• Laparoscopy is a surgery that uses a thin,
lighted tube put through a cut (incision) in
the belly to look at the abdominal organs
(peritoneal cavity) or the female pelvic
organs. Laparoscopy is used to find
problems such as cysts, adhesions,
fibroids, and infection. Tissue samples can
also be taken for biopsy through the
tube/instrument (laparoscope).