Disorders of Blood Cells Flashcards
Characteristics of Blood
- Blood is a liquid tissue
* Blood is 45% cells and 55% plasma
Contents and characteristics of plasma
• The liquid part of blood
o Dissolved solutes such as sodium, potassium, bicarbonate, electrolytes, hormones, cytokines and other particles
• 93% of plasma is water, and 7% of plasma is protein, mainly albumin, immunoglobulins (gammaglobulins)
Characteristics of serum
- The fluid remaining after blood clots
- Analyzed for most blood lab tests
- Since it doesn’t contain fibrinogen (a coagulation protein) so it doesn’t clog the lab equipment
What are the formed elements
• Erythrocytes (RBC), leukocytes (WBC), and thrombocytes/platelets
Characteristics of RBC
- intact whole cells
- are most abundant (they need to transport oxygen)
Characteristics of platelets
are the fragments of the cytoplasm of a bone marrow cell (megakaryocyte)
Where do formed elements reside in?
Bone Marrow
Characteristics of Red Marrow
In central cavity of bones of the spine, pelvis, ribs, cranium, and the proximal ends of long bones
25% develops RBC
75% develops WBC (because they have a shorter life span)
Characteristics of yellow marrow
stores fat and can become red marrow if necessary
Where do blood cells also exist
Spleen, lymph nodes, thymus
What does the quantity of cells depend on?
o Life span
o Rate of production
The generation of blood cells
Hematopoiesis
What do all cells arise from?
Pluripotent hematopoietic stem cell
What does the pluripotent stem cell give rise to?
2 multipotent stem cells
What is another name for the multipotent stem cells
Progenitor cells
What do progenitor cells give rise to?
- Lymphoid Progenitor Cells
- Myeloid Progenitor Cells
What do lymphoid progenitor cells give rise to
-Lymphocytes
(T cells (mature in thymus) B cells (mature in bone marrow and turn into plasma cells))
-Leukocytes
-WBC
What do myeloid progenitor cells give rise to?
- Granulocytes (Neutrophils, basophils, eosinophils)
- Monocytes
- Erythrocytes
- Megakaryocytes
Do white blood cells contain a nucleus?
Yes
What is the role of granulocytes?
(Neutrophils, basophils, eosinophils)
-Part of inflammatory reactions, have digestive enzymes, in allergic reactions
What is the role of megakayocytes
- Precussor cells to platelets
- Stop bleeding, role in coagulation
Where are blood cells made in a fetus?
Liver and Spleen
Where are blood cells made from birth on?
-Shifts to the red marrow
Do the liver and spleen retain their ability to produce cellular elements?
Yes
-Blood cell production by the liver and spleen
-Occur when the bone marrow if wiped out
Extramedullary Hematopoiesis
Where are bone marrow biopsies taken from?
Iliac crest and sternum
Characteristics of RBC (origination, life ex. components)
• Originate from myeloid progenitor cells in the marrow
• Begin nucleated, but the nucleus is ejected before the cell enters the bloodstream so there is more room for hemoglobin
• Live 120 days and iron and hemoglobin are recycled
o Hemoglobin AIC is a great test for diabetics because it tests the past 3 months glucose levels
What is usually the problem if you have low reticulocytes?
Problem with bone marrow
What is the problem if you have too high reticulocytes?
Anemia
Characteristics of hemoglobin
- Compound in RBC to which oxygen attaches to
- Functions to transport oxygen from lungs to tissues
- Synthesis requires iron, vitamin B12, vitamin B6, and folic acid
Where is erythropoietin made and what is its function?
Made in the kidney and it stimulates RBC production
How is EPO stimulated?
By the amount of oxygen delivered to the kidneys via RBC
Low oxygen, increases/decreases EPO and RBC
Increases
How many heme units are on a RBC?
4
What problems occur if you have problems with your heme state?
- Genetic defect that can cause disease
- Lacking iron- can lead to iron deficiency
- You wont have effective iron transport
What stimulates WBC production
- Hormones
- Inflammatory molecules
- Immune molecules
3 characteristics of WBC
- Nucleated phagocytic cells
- Fight microbes and non-self-invaders
- Promote repair process
What are the number of neutrophils high in?
Bacterial infection
What are the number of lymphocytes high in?
Viral infections
How long do RBC live?
120 days
How long do neutrophils, basophils, and eosinophils live?
4 days
How long do lymphocytes and monocytes live?
1 or 2 weeks
How long do platelets live?
1 week
How long does aspirin inhibit platelet activity
For the life of the platelet (so 1 week)
How are old RBC removed?
The spleen
What is the premature destruction of RBC called?
Hemolysis
What is a sign of hemolysis?
Jaundice- bc bilirubin increases in the blood and causes jaundice
Describe the laboratory assessment of formed elements
- Blood samples are taken from peripheral blood
* Anticoagulants are used to keep the sample clot free
What is included on a CBC
• RBC, WBC, White blood cell differential, hemoglobin, hematocrit, platelets
What are elevated/depressed numbers seen on a CBC if your patient has an infection
o Infection= high neutrophils and left shift (high in bacterial inflammatory responses)
This varies between men and women and it is often used
Hemoglobin
This is a percentage of the amount of blood that is RBC
hematocrit
What are examples of Red Cell indicies
- MCV
- MCH
- MCHC
Average cell size
MCV
o Average amount of hemoglobin in an average RBC
MCH
o Average concentration of hemoglobin per unit of volume in an average RBC
MCHC
What are 2 things that are important for the diagnosis of disease
- Size of RBC
- Hemoglobin concentration
Hypochromic=
too little hemoglobin
Hyperchromic
too much hemoglobin
Elevated when RBC production increases as the bone marrow increases production
Reticulocytes
• Abnormally low hemoglobin in the blood
o Decreased numbers of RBC, decreased hemoglobin, or both
Anemia
Is anemia usually a sign for an underlying condition
Yes
What is the first lab test you run to diagnoses someone with anemia
CBC and red cell indicies
What are 2 causes of anemia
- Failed bone marrow production
- RBC loss due to hemorrhage or destruction
What are symptoms of anemia
• SOB • Tired • Weak • Pale • Tachycardia o Body is demanding more O2 • Palpitations • Ticitnic • Angina o Not enough oxygen in the heart • Kidneys are going to secrete erythropoietin to increase RBC production
What is the goal of anemia
• Goal is to reestablish oxygen to tissues
o Increase SV and HR
What are 2 problems that hemorrhage creates?
-Loss of oxygen carrying capacity
-Loss of iron
(If you lose blood its hard to restore nutrients)
What are some dangers of acute blood loss?
o Lose the O2 carrying capacity
o Lose Iron
o Danger- shock and death
What type of shock can be caused by blood loss
Hypovolemic Shock
Where is chronic blood loss usually seen?
Through the GI tract (from colon, or uterus usually)
Is blood loss fast or slow in chronic blood loss?
Slow, trickling blood loss
If you are over 50 and you present with anemia, what is probably your diagnosis?
• GI/Colon carcinoma until proven otherwise
What can cause chronic blood loss in a young female?
Menstrual periods
What are 4 main features of anemia?
- Short RBC life span
- Active hypercellular bone marrow
- Increased blood erythropoietin
- Blood that contains high amounts of reticulocytes or new RBC
Why is the bone marrow hypercellular?
because the bone marrow works overtime to try to replace dying cells
Why is EPO high?
secreted by the kidney to stimulate more RBC production
How are most anemias caused?
Genetic defects
What are 4 kinds of genetic anemias?
- Sickle cell
- Hereditary Spherocytosis
- Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD)
- Thalassemia
What is the mutation that causes Sickle cell?
- Point mutation of chromosome 11
* Substitution of valine (hydrophobic) instead of glutamine acid (hydrophilic)
How does this mutation effect the cell?
Changes the 3D shape
What type of anemia do patients with Sickle cell present with?
Normocytic Normochromic
What triggers Sickle Cell anemia?
- Mostly in hypoxic situation
- Lose hemoglobin F
- Hypoxic injury that decreases oxygen and changes the ability for O2 to be traveled on cells
Can Sickle cell be reversed?
Yes- if you remove the cause of hypoxia
-At some point it’s not reversible and it can occlude vessels
What can Sickle cell cause?
• Infections caused by loss of splenic immune function
o Accumulated infarcts destroy the spleen
o Strep pneumonia, salmonella
What is treatment for Sickle cell?
o Increase hemoglobin F (fetal hemoglobin)
o Pain control
o Hydration
o Make sure they have vaccines (meningitis, pneumonia, influenza)
Describe hereditary Spherocytosis
• Spectrin mutation, in cell membrane and allows it to be flexible
• When mutation, it can cause destruction cause it can’t move and deform easily
o Mild anemia, jaundice, splenomegaly
Describe G6PD
- X linked recessive genetic disorder that causes deficiency of G6PD in RBC
- G6PD is important in the in the supply of energy to stabilize the RBC membrane
- Mutation causes the RBC to be fragile and susceptible to destruction
Describe Thalassemia
- A group of microcytic (low MCV) hemolytic diseases that tend to occur in people of Mediterranean decent
- Impairs synthesis of the alpha or beta peptide chains of the globin protein of hemoglobin
What does thalassemia impair?
• The genetic defect effects the amount of hemoglobin synthesized
Describe the cells in thalassemia
- Rendered the RBC fragile and susceptible to hemolysis
* RBC are pale and normal and lack the amount of hemoglobin in the cytoplasm
Describe the RBC in thalassemia
• Causes microcytic hypochromic RBC
What are examples of non-genetic hemolytic anemias
- Iron defieciency
- Megaloblastic (Macrocytic)
- Perniciuos
- Anemia of chronic disease
- Aplastic anemia
