Disorders of Red Blood Cells and Anemias

Question 1

describe the process of hematopoiesis–where does it begin?

Answer 1

hematopoiesis (or the formation of new blood cells) begins in the yolk sac and transitions into the liver temporarily before finally establishing definitive hematopoiesis in the bone marrow (7 months gestation) and thymus.

Question 2

What stimulates hematopoiesis to start?

Answer 2

Hematopoiesis is stimulated by several different cytokines.

EPO: erythropoietin: stimulates RBC
GM-CSF: granulocyte-monocyte stimulating factor: stimulates progenitors for granulocytes, monocytes, erythrocytes, and megakaryocytes
G-CSF: granulocyte colony stimulating factor: promotes the proliferation of neutrophils
M-CSF: macrophage colony-stimulating factor: induces macrophage colonies
thrombopoietin: stimulates the differentiation of thrombocytes

Question 3

list and describe the major components of normal blood: plasma, plasma proteins

Answer 3

plasma is a transport vesicle for nutrients, chemical messengers, metabolites, and other materials.
ex: plasma carries hormones from their site of secretion to the target organ

plasma proteins: the most abundant solutes in the plasma. Albumin, globulins, and fibrinogen are the top solutes.

Question 4

list and describe the major components of normal blood: erythrocytes and platelets

Answer 4

erythrocytes are the most numerous of the formed elements, biconcave discs, primary function is to carry oxygen to the body’s tissues by the oxygen carrying protein hemoglobin within them.

platelets: circulating cell fragments of the large megakaryocytes derived from the myeloid stem cell. Contribute to formation of the platelet plug to help control bleeding. last only 10 days.

Question 5

list and describe the major components of normal blood: normal hct and Hb count range

Answer 5

hct: hematocrit: red blood cells
normal range
Men: 40-50%
Women: 37-47%

hb: hemoglobin
The normal range for hemoglobin is:
Men: 14-16.5 g/dL
Women: 12-15 g/dL

Question 6

describe the function of hemoglobin

Answer 6

the function of hemoglobin is to transport oxygen throughout the body.

Question 7

describe the synthesis of hemoglobin

Answer 7

hemoglobin is synthesized by eight enzymes, four of which work in the mitochondria and four in the cytosol.

Globin chain production occurs in the cytosol of erythrocytes and occurs by genetic transcription and translation.

Question 8

Describe the factors necessary for red blood cell production and destruction.

Answer 8

ask

Question 9

explain the role of hemoglobin in o2 and co2 transport

Answer 9

Hemoglobin with bound carbon dioxide and hydrogen ions is carried in the blood back to the lungs, where it releases the hydrogen ions and carbon dioxide and rebinds oxygen. Thus, hemoglobin helps to transport hydrogen ions and carbon dioxide in addition to transporting oxygen.

Question 10

explain the role of the kidney in RBC production

Answer 10

To get the marrow to make red blood cells, the kidneys make a hormone called erythropoietin, or EPO.

Question 11

state the meaning of the RBC count, percentage of reticulocytes, hemoglobin, hematocrit, and recall the right ranges for HCT and Hb.

Answer 11

A red blood cell (RBC) count is a blood test that tells you how many red blood cells you have.

percentage of reticulocytes is: A reticulocyte count is used to determine the number and/or percentage of reticulocytes in the blood to help evaluate conditions that affect red blood cells (RBCs), such as anemia or bone marrow disorders.

hemoglobin count: The hemoglobin count is an indirect measurement of the number of red blood cells in your body. When the hemoglobin count is higher than normal, it may be a sign of a health problem.

hematocrit is: A hematocrit test measures the proportion of red blood cells in your blood.

ranges on other flashcard

Question 12

describe the clinical manifestations (patient’s symptoms) of anemia

Answer 12

weakness, SOB, pallor, cold hands and feet, susceptible to infection, pica.

Question 13

describe the etiology and characteristics of blood loss anemia

specifically microcytic hypochromic anemia

Answer 13

etiology: Trauma, GI bleeding, surgical blood losses, peripartum

characteristics of blood loss anemia:
more often acute, including symptoms of hypovolemia and impaired oxygen delivery to tissues

etiology: caused by an iron deficiency in the blood
microcytic hypochromic anemia: low count in microcytic and hypochromic RBCs, hemoglobin less than 8 g/dl

Question 14

Describe hemolytic anemia in relation to extrinsic forms & preferred approach to management— (hint: underlying cause)

Answer 14

extrinsic forms: Trauma, Drugs, Bacterial Toxins (Sepsis), Immune Mediated response to antigen

preferred approach to management: treat the underlying cause that is stimulating the anemia.

Question 15

describe the inherited disorder of sickle cell anemia

Answer 15

sickle cell anemia is a an inherited anemic disorder most common in African American populations. The anemia presents with the red blood cells looking like sickles, causing problems with their movement throughout the blood stream.

Inherited disorder in which an ABNORMAL HEMOGLOBIN (hemoglobin S [HbS]) leads to chronic hemolytic anemia, pain, and organ failure.

Recessively inherited 2 forms:
Heterozygous: sickle cell trait
Homozygous: sickle cell disease

Question 16

explain the causes and consequences of sickling in sickle cell anemia

Answer 16

Causes: Decreased oxygen tension (hypoxia) deoxygenated hemoglobin aggregates and polymerizes in cytoplasm, shape of cell is altered
Returns to normal once oxygenation improves
Repeated episodes can alter shape permanently
RECALL ‘shelf life’ of RBCs; any hypoxia, stressor event

Consequences:
Chronic hemolytic anemia
Blood vessel occlusion

Question 17

Compare anemias of decreased RBC production: Iron deficiency anemia, megaloblastic (B12 and folic acid deficiency) anemia, and aplastic anemia.

Answer 17

IDA: Cause: Chronic blood loss, resulting not enough Iron for heme, problem of supply/demand.
symptoms on other card but quick recap is cold, susceptible to disease, fatigued, SOB, etc.

B12 anemia: cause: vitamin b12 deficency due to malabsorption
symptoms: mild jaundice, parathesia of feet/fingers, loss of position and sense &spastic ataxia

folic acid anemia: cause: Malabsorption due to long term alcohol use, intestinal disease (i.e. celiac), restriction of carb
symptoms: anemia, tiredness, pregnant mothers: fetus defect neural tube

aplastic anemia: reduction in all cells, not just rbc cause: exposure to environmental factors like radiation, chemotherapy, poor immunity
symptoms: weakness, fatigue, pallor, susceptible to infection, petechiae, ecchymoses.

Question 18

explain the mechanism of anemia in chronic renal failure.

Answer 18

because there is no EPO in end stage renal disease, anemia becomes present as no red cells are being made.

Question 19

Define secondary polycythemia, and its role as a compensatory mechanism.

Answer 19

a rare condition in which your body produces an excess amount of red blood cells.

It occurs when hemoglobin is not able to pick up large amounts of oxygen from the lungs (i.e., when it is not “saturated”).

So the body tries to compensate by making a bunch of red blood cells that are immature.

and it’s bad