CBC Flashcards
How much blood do we circulate?
5L
What percent of blood is plasma?
55%
What percent of plasma is water?
90%
What percent of blood is cells (RBCs, WBCs, platelets)?
45%
What is the most numerous cell in the blood?
Erythrocytes (RBCs)
What is the function of RBCs?
Carry oxygen to all parts of the body and bring CO2 back to the lungs
What is the largest cell present in blood?
Leukocytes (WBCs)
Which cells do we have the least of in our blood?
Leukocytes
What is the smallest cell present in blood?
Thrombocytes (platelets)
Which cells are essential for coagulation?
Thrombocytes (platelets)
What is the production of all types of blood cells?
Hematopoiesis
Where does hematopoiesis occur?
Bone marrow
and lymphatic tissue in adults
How does a CBC with differential differ from just a CBC?
CBC with diff contains specifics of WBCs while a CBC only shares the total number of WBCs
What is the normal value of RBCs?
Approx. 4-6 million RBCs/microliter of blood
- differs slightly in males and females
- Newborns can have more
What can cause an RBC count to appear higher than normal?
-Dehydration
-Severe diarrhea
-Acute poisoning
These cause less water to be in our blood making more room for RBCs in the sample collected
What can actually cause an RBC count to be higher than normal?
-Chronic lung disease
Need more RBCs because need more O2 circulating
What can actually cause an RBC count to be lower than normal?
Anemia
What is the main component of erythrocytes?
Hemoglobin
What does hemoglobin measure?
-Number of RBCs
-Oxygen carrying capacity of RBCs
(used to diagnose/evaluate/treat types of anemia)
How many amino acids is one heme molecule made of?
4
2 alpha chains, 2 beta chains
What is the normal range for hemoglobin?
Males: 14-18 g/dL
Females: 12-16 g/dL
*12-15 is a good marker
What happens if hemoglobin count is too high?
Hgb > 20.0 g/dL can cause clogged capillaries
What diseases can cause an increase in hemoglobin?
- COPD
- CHF
What does a hematocrit/packed cell volume (PCV) measure?
Weighted part of RBCs (percentage by volume of packed RBCs in whole blood)
What is the ratio of Hgb:Hct?
1:3
What is the normal value of a hematocrit?
Males: 42-52%
Females: 37-47%
What values are dangerous for a hematocrit?
Hct < 15% can lead to cardiac failure/death
Hct > 60% is associated with spontaneous blood clotting
What is a reticulocyte?
Young, immature, non-nucleated RBCs that are released from bone marrow early b/c old RBCs are failing
What is a normal value for a reticulocyte count?
0.5-2.0% of RBCs
What values are dangerous for a reticulocyte count?
> 2.0% means something is wrong because too many are being released
< 0.5% bone marrow failure/nutritional deficiences
What does Mean Corpuscular Volume (MCV) describe and what are normal values?
- Describes the SIZE of the RBC
- Normal = 80-100 mm3
What terms are used to describe different MCV values?
- Normocytic (80-100)
- Microcytic (<80)
- Macrocytic (>100)
What does Mean Corpuscular Hemoglobin (MCH) measure?
- Average amount of Hgb in RBC
- Closely resemble MCV because bigger RBC can hold more Hgb and smaller RBC holds less Hgb
What does Mean Corpuscular Hemoglobin Concentration Measure (MCHC)?
Average concentration of percentage of Hgb within each RBCs
COLOR
What terms are used to describe different MCHC values?
- Normochromic (32-36 g/dL)
- Hypochromic (pale color, <32)
- Hyperchromic (bright red, >36)
What does RBC Size Distribution Width (RDW) measure?
Variation in size or volume of RBCs
What is the term for a high RDW and what does it mean?
Anisocytosis
- Lots of variation in the size of RBCs
- Normal range is 11.5-14.5%
When is a peripheral smear used?
When a abnormal value appears on a CBC
What does an Erythrocyte Sedimentation Rate (ESR) measure?
The rate at which red blood cells settle out of unclotted blood in an hour
What are indications for ordering an ESR?
Inflammation
-RBCs clump together when there is inflammation and therefore settle (fall) faster resulting in a higher ESR
