Blood Physiology and Hematology Concepts

Hematocrit (HCT) refers to the proportion of red blood cells (RBCs) in a blood sample.

A normal hematocrit value typically indicates a healthy balance of red blood cells in the blood.

A hematocrit of 40% means that 40% of the blood volume is made up of red blood cells, while the remaining 60% is plasma.

Hematopoiesis is the process of producing blood cells, including red blood cells, white blood cells, and platelets.

Erythropoiesis is the specific process of producing red blood cells.

Factors that affect erythropoiesis include iron, vitamin B12, folic acid, and erythropoietin.

Anemia is a condition characterized by a low red blood cell count or low hemoglobin levels, resulting in reduced oxygen carrying capacity in the blood.

Polycythemia refers to an abnormally high red blood cell count, leading to increased blood viscosity and potential complications.

Committed stem cells that give rise to the myeloid lineage, including red blood cells, white blood cells, and platelets.

A type of cell that gives rise to megakaryocytes, which in turn produce platelets.

Large cells in the bone marrow that produce platelets by shedding fragments of their cytoplasm.

These cells are responsible for blood clotting and wound healing.

Red blood cells, responsible for carrying oxygen throughout the body.

The shape of red blood cells, being flattened discs with a depressed center.

The ability of red blood cells to change their shape, allowing them to squeeze through narrow capillaries.

The average volume of red blood cells, usually between 90 and 95 cubic micrometers.

The size of red blood cells (RBCs) is crucial when considering renal physiology. The diameter of RBCs prevents them from crossing capillaries and entering the urine.

When interpreting CBC results, it's essential to consider the patient's gender. Different genders have varying normal ranges for certain blood parameters.

Comparing a male patient's CBC results to other males' values and a female patient's results to other females' values provides an accurate assessment of their blood health.

The function of red blood cells is to transport oxygen throughout the body.

The red blood cells are restricted from leaving the capillaries because of their size.

Hematocrit values are essential for understanding the oxygen-carrying capacity and viscosity of blood. They help indicate the efficiency of blood in delivering oxygen throughout the body.

Low hematocrit, indicating a lower than normal percentage of red blood cells. This can be caused by several factors, including anemia, bleeding, and nutritional deficiencies.

High hematocrit, indicating a higher than normal percentage of red blood cells. This can be caused by dehydration, living at high altitudes, or the misuse of erythropoietin (EPO).

The production of red blood cells in the bone marrow. This process is stimulated by erythropoietin (EPO), a hormone produced by the kidneys.

A hormone produced by the kidneys that stimulates the production of red blood cells in the bone marrow.

The bone marrow is a vital tissue responsible for the production of blood cells, including red blood cells, white blood cells, and platelets. It provides a constant supply of new blood cells to replace those that are worn out or lost.

A pluripotent hematopoietic stem cell (PHSC) is a type of stem cell in bone marrow that can differentiate into various types of blood cells, including red blood cells, white blood cells, and platelets. This stem cell is the common ancestor of all blood cells.

Living at high altitudes causes the body to produce more red blood cells to compensate for lower oxygen levels. This is a natural adaptation.

Vitamin B12 and folic acid are crucial for the maturation of red blood cells, ensuring they divide properly and function effectively.

Without sufficient vitamin B12 or folic acid, red blood cell DNA cannot be properly formed, leading to abnormal cell division and fragile, short-lived red blood cells.

These abnormally large, fragile red blood cells are called macrocytes. They have a shorter lifespan than normal red blood cells.

Cyanocobalamin is a synthetic form of vitamin B12 used to treat vitamin B12 deficiency, ensuring proper red blood cell maturation.

A condition where erythroblastic cells fail to proliferate rapidly resulting in the production of larger, fragile, short-lived red blood cells (macrocytes).

A deficiency of vitamin B12 or folic acid leads to impaired maturation of red blood cells. This results in larger, fragile red blood cells, known as macrocytes, which have a shorter lifespan.

The inability of the body to efficiently absorb vitamin B12 from the gastrointestinal tract, despite it being present in the diet.

A type of pernicious anemia caused by the inability to absorb vitamin B12 due to the lack of intrinsic factor, a protein produced by the stomach.

A type of anemia caused by the lack of intrinsic factor, which is produced by the parietal cells in the stomach.

An autoimmune disorder affecting the stomach's lining, causing the loss of parietal cells.

A condition where the gastric mucosa fails to produce normal gastric secretions, including intrinsic factor. Leading to faulty absorption of Vitamin B12

3-4 years of defective vitamin B12 absorption can lead to maturation failure and anemia.