HSC 4551 Lecture Notes - Spring 2018 Lecture 7 - Neutropenia, Chronic kidney disease, Haemophilia A
Chapter 7: Diseases and disorders of the blood
• Blood is the body’s transportation system
o Carries oxygen, glucose, and waste products around the body
o Abnormalities have systemic, devastating affects
o Made up of plasma and formed elements (Red and white blood cells, and
platelets)
• Plasma: fluid portion of the blood
o Carries nutrients, wastes, ions, hormones, clotting factors, albumin, and
antibodies
▪ Albumin: promotes the ability to hold water and maintain pressure
inside the blood vessels
• Erythrocytes (red blood cells): make up about half of the bloods volume
o There are approximately 5 million / mm^3 in females and 4.5 million /
mm^3 in males
o Mature red blood cells have no nucleus, which means they cannot grow or
repair
o Specialized to carry oxygen, so they are biconcave sacs filled with iron-rich
oxygen carrying protein, hemoglobin
▪ Hemoglobin: most important component of RBCs
• Composed of globin and heme
• Binds to oxygen in the lungs and becomes oxyhemoglobin and
are then transported to the body’s tissues
o Have a brief lifespan (120 days)
o Removed by the liver and spleen
o New RBCs are produced in the red bone marrow which is in the vertebrae
and sternum
o Erythropoiesis: process of red blood cell formation regulated by
erythropoietin
▪ Process begins with large nucleated stem cells that go through a
series of stages before becoming RBCs
▪ In the process hemoglobin accumulates within the cytoplasm and the
nucleus disappears
▪ Mature RBCs emerge from the bone marrow as reticulocytes
• Leukocytes (white blood cells): produced in the bone marrow from their respective
stem cells
o Primary function is to defend tissues against infections and foreign
substances
o 5 types:
▪ Neutrophils
▪ Eosinophils
▪ Basophils
▪ Monocytes
▪ Lymphocytes
o Abnormal numbers, inherited acquired defects, and neoplastic alterations in
WBCs result in disease and disability
• Platelets: produced in the bone marrow and are essential for clotting
o During clot formation, platelets become sticky and trigger the deposition of
an insoluble clotting protein called fibrin and they form a dense mesh at a
wound, preventing blood loss
• Diagnostic tests and procedures:
o Blood tests: measure total blood counts, hemoglobin, hematocrit, serum
chemistry, and enzyme and hormone levels
o Differential blood analysis: provides qualitative information such as size,
shape, and ratio of one cell type to another
o Bone marrow smear: used to diagnose malignant blood disorder and
increases/decreases in blood counts
▪ Obtained through needle aspiration of the bone marrow and bone
marrow cavity
o Bone marrow analysis: provides information on the function of the bone
marrow and the qualitative characteristics of stem cells that give rise to all
blood cells
• Anemia: condition of an abnormally low number of RBCs that leads to reduced
delivery of oxygen and nutrients to the tissues
o Causes: hemorrhage, nutrition deficiency, and chronic disease
o Symptoms: fatigue, decreased tolerance for exercise, dyspnea, and
palpations
▪ Due to tissue hypoxia (lack of oxygen)
o Major sign is pallor
o Jaundice and enlargement of the spleen occurs with anemia caused by
hemolysis
o Cardiac signs include tachycardia (rapid heart beat) or murmurs
o Clinical diagnoses requires a microscopic analysis of RBCs
o Iron-deficiency: anemia when there’s iron deficiency
▪ Leading cause of anemia world side
▪ Prevalence is greatest among preschoolers, adolescents, and females
▪ Risk factors:
• Excessive blood loss, menstruation, pregnancy, and rapid
growth during adolescence
▪ Amount of iron required in a diet is about 1-1.4 mg
▪ Stages:
• Negative iron balance: demands for iron exceed the body’s
ability to absorb iron
• Iron stores in the body become depleted
o Synthesis of hemoglobin becomes impaired
o RBCs will lose their shape and appear cigar-shaped
▪ Signs and symptoms: weakness and fatigue
• Mild-moderate deficiency can affect cognitive performance,
behavior, and growth in children
▪ Treatment: oral supplementation
