Blood and Immunity Flashcards
What are the functions of blood?
- transport gases, nutrients, hormones and metabolic wastes
- regulates interstitial fluid composition
- restricts fluid loss at injury sites (blood clotting)
- defends against toxins and pathogens
- regulates body temperature
What is hematocrit?
the % of total blood volume occupied by packed red blood cells
What are the constituents of blood?
46-63% plasma and 37-54% formed elements
Where are most plasma proteins made?
Liver
What are the functions of plasma proteins? With specific examples too.
Generate colloid osmotic pressure (alb.) and buffer pH
Albumins - carriers
Globulins - clotting factors, enzymes, carriers, antibodies (found in y)
Fibrinogen - cleaved to form fibrin in blood clotting
What consists of formed elements?
red blood cells (erythrocytes) - 99.9%
white blood cells (leukocytes) - 0.1%
platelets (thrombocytes)
What makes of the white blood count and what are their general roles?
Lymphocytes
Phagocytes: role - engulfing
- monocytes and neutrophils
Granulocytes: - neutrophils, eosinophils, basophils
What are blood cells made up of?
Filled with hemoglobin and enzymes
Describe the structure of a hemoglobin.
2 alpha, 2 beta chains and 4 hemes which contain one iron atom and can bind to an oxygen
What is the balance of production and removal of RBCs?
2-3million made/second and have a lifespan of about 120 days
Describe erythropoiesis
The formation of RBC begins with precursor cells in the bone marrow.
It requires iron, vitamin B12, and folate in the diet
What are the properties of a mature RBC?
Anaerobic metabolism and no nucleus (no DNA)
What is erythropoietin?
a hormone made in the kidney that promotes erythropoiesis
produced in response to low oxygen levels
Describe hematopoiesies
the process of producing blood cellular components from pluripotent hematopoietic stem cells
25% developing erythrocytes and 75% leukocytes
