Peripheral Blood Flashcards
1
Q
Proteins in plasma
A
- Albumin (major component): maintains osmotic pressure of blood, plays a role in transport of water-insoluble substances
- Gamma globulins (immunoglobulins): antibodies
- Fibrinogen: necessary for the formation of fibrin during blood clotting
- Complement proteins: inflammation and destruction of microorganisms
- Other solutes: electrolytes, nitrogen substances, nutrients, gases, hormones, enzymes
2
Q
Layers of centrifuged blood
A
- Lowest layer: RBCs, ~45% of blood volume. Hematocrit - % of blood volume occupied by RBC
- Middle Layer (buffy coat): ~1% of blood volume, white/gray in color, has leukocytes and platelets
- Upper layer: blood plasma, ~50% of blood volume, yellowish translucent supernatant
3
Q
Structure of erythrocytes
A
- Biconcave discs without nuclei (large surface to volume ratio)
- Diameter 6.5-8.0 um
- Bind eosin deeply around periphery
4
Q
Factors influencing the ability of RBCs to change shape
A
- Geometry (biconcave shape)
- Cytoplasmic viscosity (intracellular hemoglobin concentration)
- Properties of plasma membrane (3 layers)
5
Q
Membrane skeleton of RBCs
A
- Network of peripheral proteins
- Attached to cytoplasmic side of lipid bilayer
- Spectrin, actin, and protein 4.1
- Influences deformability of membrane
- Stabilize membrane against shearing forces
6
Q
Hemoglobin
A
- constitutes about 1/3 of cell weight
- responsible for viscosity
- globular chromoprotein
7
Q
Hemoglobin A1 (HbA1)
A
- major form of hemoglobin in adults (95%)
- consists of 2 alpha and 2 beta chains
8
Q
Hemoglobin A2 (HbA2)
A
- minor form of hemoglobin in adults (5%)
- consists of 2 alpha and 2 delta chains
9
Q
Hemoglobin F (HbF)
A
- Produced during the intrauterine period
- Consists of 2 alpha and 2 gamma chains
10
Q
Hemoglobin S (HbS)
A
- Single nucleotide mutation in DNA coding for beta chains (glutamic acid –> valine)
- Leads to sickle cell disease: RBC are inflexible and have reduced life span, can lead to anemia and can increase blood viscosity
11
Q
Function of RBCs and number of cells
A
- Transportation of gases: O2 from alveoli to tissues and CO2 from tissues to alveoli
- Males: 4.1-6 x10^6/ul
- Females: 3.9-5.5 x 10^6/ul
- Number influenced by altitude
12
Q
Life span of RBC
A
- Survive in circulation for about 120 days
- Senescent RBCs are removed by macrophages
13
Q
Reticulocytes
A
- RBCs recently released from bone marrow
- Contain small amount of ribosomal RNA (stains bright blue, appears as a net-like cytoplasmic structure)
- Make up ~1% of circulating RBCs
- Useful indicator of rate of RBC production (good for anemias, bone marrow regen. etc.)
14
Q
How do leukocytes leave blood vessels?
A
Through diapedesis - either between cells or through cells
15
Q
Classification of leukocytes
A
- Granulocytes: neutrophils, eosinophils, basophils
- Agranulocytes: lymphocytes and monocytes
16
Q
Number of leukocytes
A
- 6,000-10,000/ul (7,500) Relative frequencies: - Neutrophils 60-70% - Eosinophils 2-4% - Basophils 0-1% - Lymphocytes 20-30% - Monocytes 3-8%