Hematology and Immunology
• Hematology is the medical specialty that
studies the anatomy and physiology of the
blood and uses diagnostic tests, medical and
surgical procedures, and drugs to treat blood
diseases.
Hematology and Immunology
• Immunology is the medical specialty that
studies the anatomy and physiology of the
lymphatic system and uses diagnostic tests,
medical and surgical procedures, and drugs to
treat lymphatic and immune response
diseases.
Figure 6-1 Lymphatic system
Anatomy and Physiology (cont’d)
• The Blood
– Contains blood cells, blood cell fragments, water,
and other substances (proteins, clotting factors,
etc.)
– Transports oxygen, carbon dioxide, nutrients, and
waste products
– Contains cells that also function as part of the
immune system
Anatomy and Physiology (cont’d)
• The Lymphatic System
– Consists of the lymphatic vessels, lymph fluid,
lymph nodes, lymphoid tissues, and lymphoid
organs
– Forms a pathway throughout the body that is
separate from that of the cardiovascular system
that contains the blood
– Defends the body against microorganisms and
cancerous cells
Anatomy of the Blood
• Plasma
– Clear, straw-colored liquid (about 90% water) that
makes up 55% of the blood.
– The formed elements of the blood (erythrocytes,
leukocytes, and platelets) are suspended in the
plasma.
Anatomy of the Blood (cont’d)
• Plasma (cont’d)
– Contains substances the body produces itself such
as: albumin, bilirubin, hormones, complement
proteins, and clotting factors.
– Contains creatinine and urea, which are waste
products of cellular metabolism.
Figure 6-2 Plasma
Anatomy of the Blood (cont’d)
• Erythrocytes
– Most numerous of the formed elements in the
plasma
– Red blood cell that is a round, somewhat
flattened, red disk
– Unique because, unlike other body cells, they
have no cell nucleus when they are mature
Figure 6-3 Hematopoiesis.
Figure 6-4 Erythrocytes
Andrew Syred/Photo Researchers, Inc.
Anatomy of the Blood (cont’d)
• Erythrocytes (cont’d)
– Contain hemoglobin, a red, iron-containing
molecule that binds to oxygen molecules to form
oxyhemoglobin.
– Hemoglobin carries oxygen from the lungs to
every cell in the body, and carries carbon dioxide
from the cells back to the lungs.
– Hematopoiesis, the process by which all blood
cells are formed, occurs in the red marrow of long
or flat bones.
Anatomy of the Blood (cont’d)
• Erythrocytes (cont’d)
– Very immature cells are known as stem cells.
– Erythrocyte stem cells mature to become
erythroblasts and then normoblasts.
Anatomy of the Blood (cont’d)
• Erythrocytes (cont’d)
– Do not have a nucleus, so they cannot divide or
repair themselves.
– Last 120 days before they begin to deteriorate.
– Specialized cells (macrophages) break down
erythrocytes’ hemoglobin into heme and globins.
Anatomy of the Blood (cont’d)
• Erythrocytes (cont’d)
– Iron stripped from heme molecules is stored in
the liver and the spleen; the remainder of heme
molecules is converted to bilirubin.
– Bilirubin plays an important role as an antioxidant,
protecting body cells from damage by free
radicals.
Anatomy of the Blood (cont’d)
• Leukocytes
– White blood cells that include five types of cells
(neutrophils, eosinophils, basophils, lymphocytes,
and monocytes)
– Can be identified by the presence or absence of
granules in their cytoplasm and the shape of their
nucleus
Anatomy of the Blood (cont’d)
• Leukocytes (cont’d)
– Leukocytes with large granules in their cytoplasm
are categorized as granulocytes, which include
neutrophils, eosinophils, and basophils.
– Leukocytes with few or no granules in their
cytoplasm are categorized as agranulocytes, which
include lymphocytes and monocytes.
Anatomy of the Blood (cont’d)
• Neutrophils
– Most common leukocyte, making up 40 to 60% of
leukocytes in blood
– Categorized as granulocytes
– Nucleus has many segments or lobes, so they are
also known as polymorphonucleated leukocytes
(PMNs), polys, segs, or segmenters
Anatomy of the Blood (cont’d)
• Neutrophils (cont’d)
– Develop in the red marrow
– Engulf and destroy bacteria (phagocytosis)
– Live only a few days or even just a few hours if
they are actively destroying bacteria
Figure 6-5 Neutrophil
Anatomy of the Blood (cont’d)
• Eosinophils
– Make up just 1 to 4% of leukocytes
– Categorized as granulocytes; also known as eos
– Nucleus has two lobes
– Develop in the red marrow
– Engulf and destroy foreign cells (pollen, animal
dander, etc.)
– Release chemicals that kill parasites
Figure 6-6 Eosinophil
Anatomy of the Blood (cont’d)
• Basophils
– Least common leukocyte, making up 0.5 to 1% of
leukocytes
– Categorized as granulocytes; also known as basos
– Nucleus has more than one lobe
– Develop in the red marrow
– Release histamine at the site of tissue injury
– Release heparin, an anticoagulant
Figure 6-7 Basophil
Anatomy of the Blood (cont’d)
• Lymphocytes
– Make up 20 to 40% of leukocytes.
– Categorized as agranulocytes and are the smallest
leukocytes; they are also known as lymphs.
– Nucleus is round and nearly fills the cell.
– Some lymphocytes live for just a few days, while
others live for many years.
Anatomy of the Blood (cont’d)
• Lymphocytes (cont’d)
– Begin development in red marrow; some become
B cells or natural killer cells; others migrate to the
thymus to become T cells
– Present in the blood and lymph nodes; destroy
viruses and produce antibodies
Figure 6-8 Lymphocyte
Anatomy of the Blood (cont’d)
• Monocytes
– Make up 2 to 4% of leukocytes
– Categorized as agranulocytes and are the largest
leukocytes; also known as monos
– Have a large amount of cytoplasm, and nucleus is
large and kidney bean shaped
– Develop in the red marrow
Anatomy of the Blood (cont’d)
• Monocytes (cont’d)
– Are phagocytes that engulf and destroy
microorganisms, cancerous cells, dead leukocytes,
and cellular debris.
– Monocytes in the lymph nodes, intestine, liver,
pancreas, thymus, spleen, bone, and skin are
known as macrophages.
Figure 6-9 Monocyte
Table 6-1 Leukocyte Types and Characteristics
Table 6-1 (continued) Leukocyte Types and Characteristics
Anatomy of the Blood (cont’d)
• Thrombocytes
– Different from other blood cells because they are
only cell fragments
– Active in the blood-clotting process
– Begin in the red marrow as stem cells that then
become megakaryoblasts, and then mature into
megakaryocytes, a very large cell
– Cytoplasm of the megakaryocyte breaks away at the
edges to form cell fragments (thrombocytes) that
are released into the blood
Anatomy of the Blood (cont’d)
• Blood Type
– Most important blood types are the ABO and Rh
blood groups
– ABO blood group contains A, B, AB, and O
antigens
Table 6-2 ABO Blood Group
Anatomy of the Blood (cont’d)
• Blood Type (cont’d)
– Rh blood group has 47 different antigens
– Rh is positive when antigens are present on
erythrocytes
– Rh is negative when antigens are not present on
erythrocytes
Figure 6-10 A unit of blood
Shout Pictures/Custom Medical Stock Photo, Inc.
Physiology of Blood Clotting
• Platelet aggregation―Thrombocytes form
clumps to decrease blood loss
• Coagulation―Blood clot forms
• Hemostasis―Cessation of bleeding
• When clotting factors in the plasma are
activated to form a blood clot, the fluid
portion of plasma that remains is known as
serum.
Figure 6-11 Blood clot
Susumu Nishinaga/Photo Researchers, Inc.
Table 6-3 Blood Clotting Factors
Table 6-3 (continued) Blood Clotting Factors
Anatomy of the Lymphatic System
• Lymphatic Vessels, Lymph, and Lymph Nodes
– Lymphatic vessels are similar in structure to blood
vessels, but with several important differences.
– Begin as tiny lymphatic capillaries in the tissues.
Anatomy of the Lymphatic System
(cont’d)
• Lymphatic Vessels, Lymph, and Lymph Nodes
(cont’d)
– End in ducts that empty into large veins in the
neck.
– Tissue fluid enters a lymphatic capillary and
becomes lymph, the fluid that circulates through
the lymphatic system.
Anatomy of the Lymphatic System
(cont’d)
• Lymphatic capillaries have large openings in
their walls that allow microorganisms and
cancerous cells to enter.
• Lymphatic capillaries become larger lymphatic
vessels that bring lymph to the lymph nodes.
• Valves keep the lymph flowing in one
direction.
Anatomy of the Lymphatic System
(cont’d)
• Lymphoid Organs (cont’d)
– Grouped together in chains in areas where there
is a high risk of invasion by microorganisms or
cancerous cells.
– Lymphatic vessels end at ducts in the thoracic
cavity: right lymphatic duct and thoracic duct.
– Both lymphatic ducts then empty into large
veins in the neck.
Figure 6-12 Lymphatic system
Anatomy of the Lymphatic System
(cont’d)
• Lymphoid Tissues
– Contain lymphocytes and macrophages that are
active in the immune response
• Tonsils and adenoids in the oral cavity
• Appendix and Peyer’s patches in the small intestine
Anatomy of the Lymphatic System
(cont’d)
• Lymphoid Organs
– Thymus is located within the mediastinum and
helps lymphoblasts mature into T lymphocytes
– Spleen is located on left side of abdominal cavity
and is the largest organ in the lymphatic system
– Spleen removes old erythrocytes from the blood
Anatomy of the Lymphatic System
(cont’d)
• Lymphoid Organs
– Spleen also acts as storage area for whole blood,
which is released into the circulatory system
during times of danger or injury
Diseases and Conditions
• Blood
– Blood dyscrasia
– Hemorrhage
– Pancytopenia
– Septicemia
Diseases and Conditions (cont’d)
• Erythrocytes
– Abnormal red blood cell morphology
– Anemia
•
•
•
•
•
Aplastic anemia
Folic acid deficiency anemia
Iron deficiency anemia
Pernicious anemia
Sickle cell anemia
Figure 6-13 Microcytic, hypochromic erythrocytes
Joaquin Carillo Farga/Photo Researchers, Inc.
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Figure 6-14 Sickle cell
Eye of Science/Photo Researchers, Inc.
Figure 6-15 Sickle cells in a capillary
Diseases and Conditions (cont’d)
• Erythrocytes (cont’d)
– Anisocytosis
– Poikilocytosis
– Polycythemia vera
– Thalassemia
– Transfusion reaction
Diseases and Conditions (cont’d)
• Leukocytes
– Acquired immunodeficiency syndrome (AIDS)
– Leukemia
– Mononucleosis
– Multiple myeloma
Figure 6-16 Human immunodeficiency virus
Chris Bjornberg/Photo Researchers, Inc.
Figure 6-17 Acute lymphocytic leukemia
Peres/Custom Medical Stock Photo, Inc.
Diseases and Conditions (cont’d)
• Thrombocytes
– Coagulopathy
– Deep venous thrombosis (DVT)
– Disseminated intravascular coagulation (DIC)
– Hemophilia
– Thrombocytopenia
Figure 6-20 Deep venous thrombosis
Diseases and Conditions (cont’d)
• Lymphatic System
– Graft-versus-host disease (GVHD)
– Lymphadenopathy
– Lymphedema
– Lymphoma
• Hodgkin’s lymphoma
• Non-Hodgkin’s lymphoma
– Splenomegaly
– Thymoma
Figure 6-19 Lymphadenopathy
Custom Medical Stock Photo, Inc.
Diseases and Conditions (cont’d)
• Autoimmune Disorders
– Diabetes mellitus, type 1
– Graves’ disease
– Hashimoto’s thyroiditis
– Inflammatory bowel disease
– Multiple sclerosis
Diseases and Conditions (cont’d)
• Autoimmune Disorders (cont’d)
– Myasthenia gravis
– Psoriasis
– Rheumatoid arthritis
– Scleroderma
– Systemic lupus erythematosus
Laboratory and Diagnostic
Procedures
• Blood Cell Tests
– Blood type
– Complete blood count (CBC) with differential
– Peripheral blood smear
Table 6-4 Complete Blood Count (CBC) with Differential
Table 6-4 Complete Blood Count (CBC) with Differential
Laboratory and Diagnostic
Procedures (cont’d)
• Coagulation Tests
– Activated clotting time (ACT)
– Partial thromboplastin time (PTT)
– Prothrombin time (PT)
Laboratory and Diagnostic
Procedures (cont’d)
• Other Blood Tests
– Blood chemistries
– Ferritin
Figure 6-20 Blood chemistry analyzer
Alvis Upitis/Jupiter Images – PictureArts Corporation/Brand X Pictures – Royalty Free
Laboratory and Diagnostic
Procedures (cont’d)
• Other Blood Tests (cont’d)
– Human immunodeficiency virus (HIV) tests
• ELISA―First screening test done for HIV
• Western blot―Used to confirm a positive ELISA and
make a diagnosis of HIV infection
• Viral RNA load test―Measures tiny amounts of HIV
RNA and monitors progression of the disease and
response to antiretroviral drugs
Laboratory and Diagnostic
Procedures (cont’d)
• Other Blood Tests (cont’d)
– Human immunodeficiency virus (HIV) tests
(cont’d)
• p24 antigen test―Detects the protein p24 in HIV
• CD4 count―Used to monitor the progression of the
disease and response to antiretroviral drugs
– Total iron-binding capacity (TIBC)
Laboratory and Diagnostic
Procedures (cont’d)
• Saliva Test
– OraSure
• Quick screening test that is done in the doctor’s office
or clinic. It uses the same technology as the ELISA blood
test.
Laboratory and Diagnostic
Procedures (cont’d)
• Serum Tests
– Electrophoresis
– Monospot
Laboratory and Diagnostic
Procedures (cont’d)
• Urine Tests
– Bence Jones protein
– Schilling test
Laboratory and Diagnostic
Procedures (cont’d)
• Radiologic Procedures
– Color flow duplex ultrasonography
– Lymphangiography
Medical and Surgical Procedures
• Medical Procedures
– Bone marrow aspiration
– Phlebotomy
– Vaccination
Figure 6-21 Phlebotomy
Getty Images – Photodisc-Royalty Free
Medical and Surgical Procedures
(cont’d)
• Blood Donation and Transfusion Procedures
– Blood donation
– Blood transfusion
Medical and Surgical Procedures
(cont’d)
• Blood Donation and Transfusion Procedures
(cont’d)
– Bone marrow transplantation (BMT)
– Plasmapheresis
– Stem cell transplantation
Figure 6-22 Stem cell
Dr. Yorgos Nikas/Photo Researchers, Inc.
Medical and Surgical Procedures
(cont’d)
• Surgical Procedures
– Lymph node biopsy
– Lymph node dissection
– Splenectomy
– Thymectomy