Lab 9 Flashcards
What is the blood plasma composed of?
- 90% water
- dissolved substances: glucose, ions, proteins, and hormones
What are the formed elements of the blood?
- platelets
- RBCs
- WBCs (leukocytes)
What do the features of the RBC allow it to do?
- small (7um in diameter-slightly larger than capillary diameter)
- biconcave cells with strong flexible membranes
- this allows RBCs to pass through the microcirculation and provide greater SA for the diffusion of gas molecules
What are the 5 types of circulating WBCs?
- eosinophils
- basophils
- neutrophils
- monocytes
- lymphocytes
- can be classified as granular or agranular
How many new erythrocytes are produced each day?
- 10^12 via erythropoiesis
- 120 day life span
- travel 480km during that time
What can be indicated by immature neutrophils in the blood?
-disorder in the bone marrow such as leukemia
Describe the granule and nucleus type of: RBC, eosinophil, basophil, neutrophil, monocyte, lymphocyte
RBC: no granules, no nucleus
Eosinophil: acidophilic specific granules (red), bilobular nucleus
Basophils: basophilic specific granules (blue), single spherical nucleus
Neutrophil: granules present (neutral staining), multilobular nucleus (2-5 lobes)
Monocyte: no granules, kidney shaped nucleus
Leukocyte: no granules, single spherical nucleus
What triggers RBC production?
Hypoxia which can result from:
- CV condition that limits blood flow to tissue (eg. stenosis in atherosclerosis)
- reduction in oxygen carrying capacity of blood (eg. anemia)
- too little oxygen enters blood (increase in altitude)
What is the most abundant leukocyte in the blood? What are the functions of the leukocytes?
- neutrophils
- phagocytosis, mediate immune responses, mediate inflammatory responses
What is hemolysis?
- plasma membrane of RBC is broken and hemoglobin leaks out
- can happen because of old age, trauma, and changes in osmotic pressure
What is crenation?
-formation of abnormal notching around the edge of an erythrocyte when it shrinks after suspension in a hypertonic solution
Why are patients rehydrated with 0.9% saline rather than water?
- to maintain blood tonicity
- hemolysis occurs if solution is hypotonic to RBCs
- crenation occurs is solution is hypertonic to RBCs
- hypotonic has less solute concentration than cytosol of RBC therefore water moves into the cell faster than it leaves; RBCs swells and bursts
- pure water is hypotonic to RBCs and can cause rapid hemolysis (can be used to treat dehydrated patient)
What is tonicity?
- effect of an extracellular solution on the volume of a cell
- determined by the relative concentration of non-penetrating solute molecules
- isotonic solution has same concentration as intracellular fluid (eg. 0.9% NaCl and 5% glucose)
- hypotonic has lower concentration and hypertonic has higher concentration
What is hematocrit?
- the percentage of red blood cells in the whole blood which have been packed by centrifugation for a fixed period of time
- volume of packed cells per 100mL of blood is the hematocrit or packed cell volume (PCV)
How can hemolysis occur in a blood transfusion?
- incompatible blood transfusion causes agglutination reaction
- antibodies in plasma bind to donor RBCs
- RBCs become cross linked when Ag-Ab complexes form
- activate complement which makes plasma membrane of donated RBC leaky causing hemolysis