Hematology Flashcards
How much blood is in the body?
6 quarts (5.5 L)
List the functions of blood
- Delivery of substances needed for cellular metabolism
- Removal of wastes of cellular metabolism
- Defense against invading microorganisms
- Regulation of body temp
- Maintenance of acid-base balance
What % of whole blood is plasma?
55%
What % of whole blood is formed elements?
45%
List the 3 types of plasma proteins
- Albumin
- Globulins
- Fibrinogen
Albumin
Plays a role in vascular, transport, & metabolic processes
List 3 types of globulin plasma proteins
- Alpha
- Beta
A &B helps transport iron, fat soluble (lipids) - Gamma
Immunoglobulins or Ab that help fight infection
Fibrinogen
Plays a role in clotting
All plasma proteins are manufactured by what organ?
liver
Formed elements
Suspended in plasma
Finite lifespan (limited)
Originate from stem cells
List examples of formed elements
Erythrocytes (RBCs)
Leukocytes (WBCs)
-Granular
-Agranular
Thrombocytes (PLTs)
Erythrocytes (RBCs)
Most abundant
Make up ~ half of the blood volume
Play a role in tissue oxygenation
Erythrocytes (RBCs) contains
Hemoglobin
-Gases → Mainly transports O2 throughout the body & minor role of carrying CO2
-Electrolyte → imbalances can effect how O2 is transported
-Regulates diffusion through the cell membrane
List some characteristics of erythrocytes (RBCs)
Biconcave disc
Has no nucleus
Flexible
Has no cytoplasmic organelles (No protein synthesis)
Life span of 120 days
RBCs concave structure is…
Ideal for gas exchange & diffusion in & out of the cell
RBCs have ____ ____ to move throughout the body
Reversible deformity
List the different types of Hgb
- Hb A → Adult (normal)
-Oxygen carrying protein - Hb F → fetal
- Hb S → sickle cell
- Hb A1c → Glycosylated
Hemoglobin molecule is composed of…
4 polypeptide chains
- Alpha 1, Alpha 2
- Beta 1, Beta 2
1 Hgb molecule carries how many oxygen atoms?
1 Hgb molecule carries 4 oxygen atoms
Iron → Hemoglobin → O2
Synthesis of hemoglobin (Hgb) is greatly dependent on availability of iron
How can we as humans get iron?
Iron comes from diet or is recycled
What happens to aged RBCs?
They are broken down in the spleen & iron returns to bone marrow for new RBCs
A lack of iron results in…
A lack of Hgb in each RBC which results in low O2 carriage in the blood
Break down of the term “hemoglobin”
Heme → iron
Globin → protein
Where are phagocytic cells located?
Spleen
Liver
Bone marrow
Lymph nodes
Where are RBCs destroyed?
Liver & spleen
Destruction of RBCs:
Recycling to form new RBCs
Iron from heme group is recycled & reused to create new RBCs & globulin chains break down into individual AA to be recycled & build new proteins
List the steps of destruction of RBCs
Heme broken down into → bilirubin → transported in blood bound to plasma proteins → until it reaches the liver where it’s made water soluble to be eliminated from body via bile
Unconjugated bilirubin
Yellow pigment produced when RBCs break down
Conjugated bilirubin
Water-soluble form of bilirubin that is produced by the liver & excreted in the bile
Abnormal RBC destruction in circulation
Hgb remains in plasma
Combines w/ protein in plasma (haptoglobin) & other proteins (i.e. albumin)
What may happen during RBC destruction in circulation associated with haptoglobin?
Haptoglobin may exceed ability of plasma proteins to bind → free haptoglobin in blood → excreted via urine
Free haptoglobin in the blood is known as _____
Hemoglobinemia
List example conditions that occur from abnormal destruction of RBCs
Hemolytic anemia
Hemolytic transfusion reaction
What is erythropoiesis
A specific series of steps in the BM that leads to the synthesis of mature RBCs
What do all RBCs start out as?
Pluripotent stem cells in the bone marrow → stimulated to become an erythroid precursor cell
Explain what happens in the series that erythroid precursor cells go through
goes through series of changes until it becomes a mature RBC released by the BM
What is an immature RBC called?
Reticulocyte
What form of RBCs have NO genetic material?
Mature RBCs
What are the nutritional requirements for adequate synthesis of healthy RBCs?
Protein
Iron
Vitamin B12
Folic acid
Iron as a nutritional element
Main nutritional elements for Hgb synthesis
What types of pts might you see high RBC levels?
Patients with chronic hypoxia → i.e. COPD
Reticulocyte count
good indicator of BM activity, because it represents recent production of RBCs
What does a high reticulocyte count indicate?
Indicates that BM is working hard to keep up with RBC loss
-I.e. of causes: Anemia & cancer
Spleen
Highly vascular organ, considered “graveyard of RBCs”
Also an organ of immunity
Role of the spleen
Removes aged, lysed, & dead RBCs from circulation
What happens to RBCs in the spleen?
Broken down into their component parts, which are recycled to make new RBCs
The spleen sequesters…
Abnormally shaped & hemolyzed RBCs & destroys them
How does splenomegaly occur?
Occurs when there is a large amount of RBC breakdown occurring in the body
Leukocytes (WBCs) Normal range & function
NR: 5,000 to 10,000/ μL
Function → to combat inflammation & infection
Two types of leukocytes & their subsections
Granulocytes:
- neutrophils
- eosinophils
- basophils
Agranulocytes:
- lymphocytes
- monocytes
Immature WBCs (timeline)
Start as myeloblast → promyelocyte → myelocyte → loss of capacity for mitosis → metamyelocytes → band cell → segmented neutrophil → that eneters blood → enters tissues (1-2 days)
Immature WBCs → left shift
Increased #s of immature neutrophils
most common cause is inflammation
can also be seen in some marrow disorders (leukemia) or severe BM injury
How are cells classified?
Based on their stage of maturation
Thrombocytes (platelets)
Large megakaryocytes → come from myeloid stem cells
Thrombocytes form the ____ _____
platelet plug
What do thrombocytes look like?
Disc shaped without a nucleus
Thrombopoietin
Hormone that is chief regulator of PLT production & are synthesized by liver
Stimulated by ↓ # PLTs in BM
How much of PLTs are squestered in the spleen?
1/3
Senescent platelets
Aged PLTs that have lost function & less able to respond to clotting factors
Cleared by splenic macrophages after average lifespan of 7-10 days
When assessing for bleeding what changes to the skin should you look for?
Petechiae
Purpura
Ecchymosis
Spontaneous bleeding
Petechiae
Pinpoint red-purple areas of bleeding that resemble a rash
Purpura
Larger purple areas of bleeding
Ecchymosis
Bruise
Spontaneous bleeding
I.e. Nosebleed (epistaxis)
What do CBCs look at?
WBCs
Hemoglobin
Hematocrit
Platelets
What is included in WBC part of CBC?
Neutrophils
Lymphocytes
Monocytes
Eosinophils
Basophils
Immature granulocytes, absolute
Neutrophils, absolute
What is included in hematocrit on CBC?
Mean corpuscular volume (MCV)
Red cell distribution width (RDW)
Mean corpuscular Hgb concentration (MCHC)
Mean cell Hgb (MCH)
Mean corpuscular volume (MCV)
size of RBC
Red cell distribution width (RDW)
range in size & shape of RBC
Mean corpuscular Hgb concentration (MCHC)
concentration of Hgb (color)
Mean cell Hgb (MCH)
Mass of RBC
What does a BMP look at?
Sodium (Na)
Potassium (K)
Chloride (Cl)
CO2
BUN/ creatinine
Glucose
EGFR
Anion gap
What is the anion gap?
Related to acid-base balance of electrolytes
What does a CMP include?
Same as BMP
Plus:
-AST (SGOT)
-ALT (SGPT)
-Alkaline phosphatase
-Total protein
-Albumin
-Bilirubin
List the different iron studies
Iron level
Ferritin
Transferrin
Total iron binding capacity (TIBC)
Iron level:
Measures amount of iron bound to Hgb
Not helpful alone
Ferritin:
Measure of iron stores
Inflammation may cause levels to increase
Transferrin:
Iron transport protein takes Fe back to the BM
List 4 other lab studies to look at
Vitamin B12
Folic acid
Hgb electrophoresis
Comprehensive metabolic profile (CMP)
Hgb electrophoresis
Looks at the globin chains
CMP measures…
14 proteins, electrolytes, enzymes, & minerals in the blood
CMP is a BMP plus
Calcium
Albumin
Total protein
Liver function studies (AST, ALT, ALP, Bili)
