CHAPTER 7 DISORDERS OF BLOOD CELLS & VESSELS

HEMATOPOIESIS Generation of blood cells Lymphoid progenitor cells = lymphocytes (WBCs) Myeloid progenitor cells = all other blood cells Red blood cells transport oxygen Hemoglobin is the compound in RBCs to which oxygen attaches for transport from lungs to tissues Synthesis depends on iron, vitamin B12, vitamin B6, & folic acid

WHITE BLOOD CELLS ACTIVE IN IMMUNITY AND INFLAMMATION Hormones and inflammatory and immune molecule mediators stimulate production of WBCs & platelets Leukocytes fight microbes & other invaders Promote the repair process

LIFE SPAN OF BLOOD CELLS Varies, shorter life span than other tissues Rapid cell turnover RBCs have longest life out of blood cells Disease of blood cells are d/t early cell death or destruction The number of WBCs, RBCs, & platelets in blood is a function of their life span and the rate of their production versus the rate of their loss

ANEMIA Low hemoglobin in blood Always a sign of some underlying condition Diagnosis: CBC Look at RBCs for either: Failed Bone marrow production Hemorrhage or destruction Treatment: Replace RBCs Identify cause and reverse it

SICKLE CELL DISEASE Autosomal recessive genetic disorder of hemoglobin synthesis Hemoglobin is molecularly defective and unstable Causing early RBC death Clinical and Pathologic findings: Obstruction of small blood vessels Anemia Hemolysis Infections

WHITE BLOOD CELL MALIGNANCIES Myeloid malignancies Myeloid cells-precursors of granulocytes, RBCs, and megakaryocytes Examples: Acute or chronic myeloid leukemia Lymphoid malignancies Lymphoid cells: B,T, or natural killer lymphocytes Example: Acute or Chronic lymphoid leukemia

ACUTE MYELOID LEUKEMIA (AML) AML: Increased numerous of myeloblasts in bone marrow and blood Occurs in all ages, common in adults over 50 years Sudden onset, symptoms appear rapidly as bone marrow becomes packed with malignant cells Symptoms: bone pain, lymphadenopathy, enlarged spleen & liver, neurologic defects Diagnosis: >20% of bone marrow cells must be myeloblasts Treatment: Chemotherapy,

CHRONIC MYELOID LEUKEMIA (CML) Slow, progressive disease Rare in children Moves through 3 phases: Indolent period Accelerated phase-resistant to treatment, increase anemia and thrombocytopenia Evolution into AML-infection and hemorrhage dangerous threats

ACUTE LYMPHOID LEUKEMIA (ALL) Malignant proliferation of immature lymphocyte precursors Usually B cells Most common malignancy of children Clinically same as AML

CHRONIC LYMPHOID LEUKEMIA (CLL) Slow onset Most patients asymptomatic, disease uncovered due to presence of another condition Constitutional S/S: Malaise, loss of appetite Mild fever Weight loss