Ch. 6 Hematology and
Immunology
Blood and the Lymphatic System
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.
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.
Two million red blood cells die every second.
There are approximately 100,000 miles of blood vessels in the human body.
Seven percent of a humans body weight is made up of blood.
Each day 400 gallons of recycled blood are pumped through the kidneys.
By donating just one pint of blood, four lives can be saved.
Half your body’s red blood cells are replaced every seven days.
Every two seconds, someone needs blood.
There are approximately 1 billion red blood cells in two to three drops of blood.
Your body usually replaces the volume of the blood you donate within 24 hours.
Anatomy and Physiology
Blood
-Contains blood cells, blood cell fragments, water,
proteins, and clotting factors.
Function: transports oxygen, carbon dioxide,
nutrients, and waste products.
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 circulatory system.
Function: Defends the body against microorganisms
and cancerous cells.
Anatomy of the Blood
1. Plasma
-Yellow-ish clear liquid (about 90% water) that
makes up 55% of the blood.
-Contains parts of the blood: erythrocytes,
leukocytes, and platelets; albumin, bilirubin,
hormones, complement proteins, and clotting
factors; creatinine and urea.
Figure 6-2 Plasma
Erythrocytes (Red Blood Cells)
-Most numerous of the parts within the plasma.
-Red blood cells are a round, somewhat flattened,
red disk.
-Do not have a nucleus. Live about 120 days.
-Contains hemoglobin (iron-containing molecule)
that bonds with oxygen and carbon dioxide.
-Hematopoiesis, the process of forming blood cells,
occurs in the red marrow of long or flat bones.
Figure 6-3 Hematopoiesis.
Life Cycle of an Erythrocytes:
Begin as stem cells, erythroblasts, normoblasts,
reticulocytes, and finally erythrocytes.
When your body experiences blood loss, the
kidneys secrete erythropoietin hormone that
stimulates the production and maturity of
erythrocytes.
When blood cells die, their parts are recycled and
stored in the body other uses.
Leukocytes (White Blood Cells)
Granulocytes:
neutrophils
eosinophils
basophils
Agranulocytes:
lymphocytes
monocytes
-Can be identified by the presence or absence of
granules in their cytoplasm and the shape of their
nucleus.
Neutrophils
-Most common leukocyte, making up 40 to 60% of
leukocytes in blood. Short lived: hours to days.
-Nucleus has many segments or lobes, so they are also
known as polymorphonucleated leukocytes (PMNs),
polys, segs, or segmenters.
-Develop from the red bone marrow.
Function: engulf and destroy bacteria.
Eosinophils
-Make up just 1 to 4% of leukocytes
-Nucleus has two lobes
-Develop in the red marrow
Function: engulf and destroy foreign cells (pollen,
animal dander, etc.); release chemicals that kill
parasites
Basophils
-Least common leukocyte, making up 0.5 to 1% of
leukocytes.
-Nucleus has more than one lobe.
-Develop in the red marrow
Function: release histamine at the site of tissue
injury; release heparin, an anticoagulant.
Lymphocytes
-Make up 20 to 40% of leukocytes.
-Smallest of the white blood cells.
-Nucleus is round and nearly fills the cell.
-Some lymphocytes live for just a few days, while others live
for many years.
-Begin development in red marrow; some become B cells or
natural killer cells; others migrate to the thymus to become T
cells.
Function: destroy viruses and produce antibodies.
Monocytes
-Make up 2 to 4% of leukocytes.
-Largest of the white blood cells.
-Have a large amount of cytoplasm, and nucleus is
large and kidney bean shaped.
-Develop in the red marrow.
Function: are phagocytes that engulf and destroy
microorganisms, cancerous cells, dead leukocytes,
and cellular debris. Are also macrophages.
Table 6-1 Leukocyte Types and Characteristics
Table 6-1 (continued) Leukocyte Types and Characteristics
Thrombocytes
-Different from other blood cells because they are
only cell fragments; also called Platelets.
-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.
Blood Type
-Rh is positive when antigens are present on
erythrocytes.
-Rh is negative when antigens are not present on
erythrocytes.
Physiology of Blood Clotting
1. Platelet Aggregation- Thrombocytes form clumps
to decrease blood loss.
2. Coagulation- Blood clot forms. (fibrin)
3. Hemostasis- Cessation of bleeding.
After clotting factors are activated, the remaining
fluid portion of plasma is called 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
Structures:
Lymphatic Vessels
Lymph
Lymph Nodes
-Similar to the blood vessels,
but have a starting point and an ending point.
Beginning Point: fluid enters a lymphatic capillary
and becomes lymph.
End Point: ducts empty into large veins in the neck.
Characteristics:
-Lymphatic capillaries have large openings in
their walls that allow microorganisms and
cancerous cells to enter.
-Valves within the system keep the lymph
flowing in one direction.
-Lymph Nodes- function to filter the lymph,
contain lymphocytes and macrophages that
destroy microorganisms.
Tissues & Organs of the
Lymphatic System
Physiology of the Immune Response
Any microorganism that can cause disease is a pathogen.
(bacteria, viruses, protozoa, fungi, yeasts)
1. Cytokines- chemicals released to injured part of body
that sends white blood cells to the area.
2. Neutrophils- engulf and destroy bacteria that have
been coated with antibodies.
3. Eosinophils- engulf and destroy any foreign cells,
worms, eggs…ect.
4. Basophils- release histamine in response to microorganisms.
5. Monocytes- engulf and destroy pathogens that have been
coated with antibodies. Also known as a macrophage.
Produce: interferon, interleukin, & tumor necrosis factor.
6. Lymphocytes
NK (natural killer) Cells- recognize and destroy pathogens.
B Cells- from the red bone marrow; work with macrophages,
produce antibodies; activate T Cells.
T Cells- from the thymus gland; Helper T-Cells, Memory T-Cells,
Cytotoxic T-Cells, & Suppressor T-Cells
7. Antibodies- coat pathogens to be destroyed
by various types of phagocytes.
Antibodies are also known as immunoglobulins.
8. Complement Proteins- nine different types;
work with antibodies and drill holes into the
pathogen’s cell wall.
Diseases and Conditions
Blood:
-Blood Dyscrasia
-Hemorrhage
-Pancytopenia
-Septicemia
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.
Figure 6-14 Sickle cell
Eye of Science/Photo Researchers, Inc.
Figure 6-15 Sickle cells in a capillary
Erythrocytes:
-Anisocytosis
-Poikilocytosis
-Polycythemia Vera
-Thalassemia
-Transfusion Reaction
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.
Thrombocytes:
-Coagulopathy
-Deep Venous Thrombosis (DVT)
-Disseminated Intravascular Coagulation (DIC)
-Hemophilia
-Thrombocytopenia
Figure 6-20 Deep venous thrombosis
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.
Autoimmune Disorders:
-Diabetes Mellitus, Type 1
-Graves’ Disease
-Hashimoto’s Thyroiditis
-Inflammatory Bowel Disease
-Multiple Sclerosis
Autoimmune Disorders:
-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
Coagulation Tests:
-Activated Clotting Time (ACT)
-Partial Thromboplastin Time (PTT)
-Prothrombin Time (PT)
Other Blood Tests:
-Blood Chemistries
-Ferritin
Other Blood Tests:
-Total iron-binding capacity (TIBC)
-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.
p24 Antigen Test―Detects the protein p24 in HIV
CD4 count―Used to monitor the progression of the
disease and response to antiretroviral drugs.
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.
Serum Tests:
-Electrophoresis
-Monospot
Urine Tests:
-Bence Jones Protein
-Schilling Test
Radiologic Procedures:
-Color Flow Duplex Ultrasonography
-Lymphangiography
Medical Procedures:
-Bone Marrow Aspiration
-Phlebotomy
-Vaccination
Figure 6-21 Phlebotomy
Getty Images – Photodisc-Royalty Free
Blood Donation and Transfusion Procedures:
-Blood donation
-Blood Transfusion
-Bone Marrow Transplantation (BMT)
-Plasmapheresis
-Stem cell transplantation
Surgical Procedures:
-Lymph node biopsy
-Lymph node dissection
-Splenectomy
-Thymectomy