Macrocytic anemia is a type of anemia in which the red blood cells are larger than their normal volume. The term ‘macrocytic’ is a Greek word meaning ‘large cell’. Macrocytic anemia comes under the morphological classification of anemia; in which anemia is classified according to the size of red blood cells. The size is reflected in the mean corpuscular volume (MCV). […]
Hematology
Pernicious Anemia: Causes, Investigations and Treatment
Pernicious anemia is a type of megaloblastic anemia that occurs when a person’s body is unable to absorb vitamin B12 from their gastrointestinal tract. This results in vitamin B12 deficiency and produces morphologically abnormal (unusually large and immature) red blood cells known as megaloblasts. It is also known as Biermer’s anemia, Addison’s anemia, or Addison-Biermer […]
Megaloblastic Anemia – Causes, Pathophysiology, Investigations and Treatment
Megaloblastic anemia is a type of anemia which is characterized by morphologically abnormal (unusually large and immature) red blood cells known as megaloblasts. Causes of Megaloblastic Anemia Megaloblastic anemia has several different causes – deficiencies of either cobalamin (vitamin B12) or folate (vitamin B 9) are the two most common causes. These vitamins play an […]
Bone marrow – Structure, Composition and Functions
Bone marrow is soft, spongy, gelatinous tissue that fills the centers of bones known as medullary cavities. Bone marrow is highly vascular meaning that it is enriched with blood vessels and capillaries. Each day bone marrow produces hundreds of billions of new blood cells. Bone marrow takes over from the liver as the major hematopoietic organ […]
Aplastic Anemia – Classification, Treatment and Prognosis
Aplastic anemia is a rare hematological (blood) disorder in which the bone marrow is damaged resulting in failure to produce all the three major types of blood cells. Bone marrow is a sponge-like tissue inside the bones that makes stem cells which develop into red blood cells (RBCs), white blood cells (WBCs), and platelets. It is also called hypoplastic anemia. The fundamental […]
Venous Blood Sampling
Venous blood sampling is a diagnostic procedure in which a needle is inserted into a particular vein and a sample of blood is collected for laboratory analysis. Venous blood is deoxygenated blood that flows from tiny capillary blood vessels within the tissues into progressively larger veins to the right side of the heart. Most of […]
What is a Capillary Blood Sample
A capillary blood sample is collected by pricking the skin. Capillaries are small vessels formed by branching of arterioles. Blood flows from the heart to arteries, which divide into arterioles, and then further divide into capillaries. After the tissue has been perfused, capillaries then unite to become venules and then widen more to become veins, […]
Blood Sample Handling and Processing
After taking a blood sample, the blood needs to be managed in a proper way so as to prepare it for investigations. Blood sample handling and processing can be summarized as below. Pre-centrifugation Handling The first critical step in the lab testing process, after obtaining the sample, is the preparation of the blood sample. Specimen […]
Vacutainer and Their Use in Blood Sampling
Vacutainer is a blood collection tube (sterile glass or plastic tube) used to collect blood samples for laboratory testing. These tubes have a closure which is evacuated to create a vacuum inside the tube thereby enabling a predetermined amount of blood to be withdrawn. Vacutainer tubes were invented by Joseph Kleiner and Becton Dickinson in 1949. Vacutainer is a registered […]
Heel Stick or Heel Lance for Blood Sampling
Heel stick or heel lance is a minimally invasive method to obtain blood sample. It withdraws capillary blood samples and is used especially in newborn screens and glucose levels. It can be used for routine tests too as lab techniques now require smaller sample volumes. Heel sticks can be used when venous access cannot be […]