Hematology: RBCs and WBCs Flashcards
(32 cards)
Characteristics of Blood cells
-Connective tissue
-Transports substances throughout the body & helps to maintain a stable internal environment
Erythrocytes
-Biconcave disks
-Contain 1/3 oxygen carrying hemoglobin
When oxygen combines with hemoglobin
The resulting oxyhemoglobin is bright red
Temperature of blood
38 C
pH of blood
7.35 to 7.45
Average volume of blood
5-6 liters (11 pints)
Amount/body weight of blood
8% of body weight
Composition of blood
-55% liquid portion (serum/plasma)
-45% formed elements
Blood includes
-RBCs
-WBCs
-Platelets
-Plasma
Blood hematocrit
Normally 45% cells and 55% plasma
Plasma
Mixture of:
-Water
-Amino acids
-Proteins
-Carbohydrates
-Lipids
-Vitamins
-Hormones
-Electrolytes
-Cellular wastes
Number of RBCs is a measure of
The blood’s oxygen carrying capacity
Typical RBC count
-Males: 4.6 mill to 6.2 mill cells per mm3
-Females: 4.5 mill to 5.1 mill cells per mm3
Embryo and fetus
RBC production occurs in the yolk sac, liver, and spleen
Adult RBC production
Occurs in the red bone marrow
Average lifespan of RBC
120 days
Total number of RBCs remains…
Relatively constant due to a negative feedback mechanism utilizing the hormone erythropoietin
When is erythropoietin released
Released in response to low oxygen levels detected in the kidneys and liver
Intrinsic factor
Produced by stomach parietal cells; aids vitamin B12 absorption in small intestine
What is needed for hemoglobin synthesis
Iron
Erythropoietin
Hypoxia induces kidneys to increase erythropoietin secretion
What is needed for DNA synthesis
Vitamins B12 and folic acid
Protein
Amino acids = globin
Erythropoiesis
-The nucleus is large in the primitive stages and reduces in size as the cell matures
-Eventually the nucleus is extruded