Lecture 25 Blood Pathology

Question 1

Compare the clinical symptoms of polycythemia and leukemia.

Answer 1

Polycythemia – overproduction of erythrocytes, resulting in high RBC count (hematocrit 80%) or as many as 11,000,000 RBC/mm3. In most cases, it is caused by hypoxemia (low blood oxygen) from smoking, air pollution or living at very high altitude (above 12,000 ft.)

Question 2

List erythrocyte disorders

Answer 2

Polycythmeia vera - over production of erythrocyte and is usually caused by a proliferation of the erythrocyte-producing cells in the bone marrow (cancer). It can be treated by radiation and bone marrow transfusion.

polycythemia - In most cases, it is caused by hypoxemia

Question 3

Contrast the causes of hemorrhagic, hemolytic, aplastic, iron deficiency, pernicious and sick cell anemia.

Answer 3

Iron-deficiency anemia – either from low iron intake or lack of vitamin B12, which is essential for hemoglobin synthesis.

Hemolytic - anemia certain diseases such as sickle cell anemia result in the spontaneous lysis of circulating erythrocytes, leading to low hematocrit (packed RBC).

Pernicious anemia – vitamin B12 deficiency either from low B12 in the diet (vegetarians), constitutional low intrinsic factor in the stomach (needed for B12 absorption) or stomach ulcers leading to insufficient HCl in the stomach ( needed to activate intrinsic factor)

sick cell anemia - This is a hereditary mutation of hemoglobin that results in the hemoglobin molecules sticking to each other and forming long rods in the cell, sickling it. It is an autosomal recessive gene (equal in males and females and both parents must be carriers.

Question 4

List leukocytes disorders

Answer 4

Leukopenia – lack of sufficient leukocytes. This is usually caused by heavy metal poisoning or radiation exposure. Certain viral and bacterial infections, or a chronic infection can also cause this.
Leukemia – this is a cancer of the leukocyte-producing tissue in the bone marrow. There are two types:
Myelocytic leukemia – affecting the myeloid series
Lymphocytic Leukemia – affecting the lymphocytes

Question 5

Describe blood clotting disorders

Answer 5

Hemophilia – a sex-linked genetic mutation resulting in the inability to produce a functional Factor VIII. This is one of many genetic disorders that result in either under-production or no production of a clotting factor.
Lack of a clotting factor interrupts the cascade and results in either a prolonged clotting time or no clotting.
Children with hemophilia used to bleed out from such simple conditions as a nose-bleed. Synthetic Factor VIII is now available for injection.