The blood Flashcards
(43 cards)
Function of blood
-Transport/Distribution of
* oxygen
* carbon dioxide
* nutrients
*wastes
* hormones
* body heat
-Defense against invasions by pathogens
*some white blood cells (Leukocytes) can phagocytize microbes and produce antibodies
-protect against fluid loss by clotting
antibodies
proteins that identify (tag) pathogens for destruction
Blood is composed of
-cell and cell fragments (formed elements)
-matrix (plasma)
* formed elements are suspended in the plasma
formed elements
-are produced in the red bone marrow
-contain RBC, WBC, platelets
Erythrocytes (Red blood cells): Function, Cell count, Anatomy
-most plentiful about 5 million RBC’s per cubic millimeter (1ul)
-carry oxygen
-biconcave disc, filled with hemoglobin (Hb) and anucleate (no nucleus)
Leukocytes (white blood cells) (WBC’s): cell count, function
-least plentiful (4,800-10,800 WBC per cubic millimeter) (1ul)
-defense against pathogens
-participate in inflammation
-capable of moving through blood vessel walls
Platelets/thrombocytes
-150,000-400,000 platelets per cubic millimeter
Hemoglobin (Hb)
-oxygen carrying protein in RBCs
-each RBC has 250,000 Hb molecules
-each hemoglobin molecule has 4 iron containing oxygen binding sites (heme groups)
-binding of O2 is reversible
-O2 binds to heme when blood oxygen increases
-O2 binds to detaches from heme when blood oxygen decreases
Granulocytes (sub-type of Leukocytes)
-name refers to granules filled with chemicals that assist in killing pathogens or promoting inflammation
-have lobed nuclei
** neutrophils, eosinophils, and basophils
Agranulocytes (sub-type of leukocytes)
-A in name refer to lack of visible granules
-spherical/kidney shape nucleus
** lymphocytes and monocytes
Neutrophils: anatomy and function
-pink cytoplasm
-small pink and purple granules
-nuclei has 3-5 lobes
-helps fight bacteria via: phagocytosis and release of granule contents
-numbers increase with bacterial infections
Eosinophils: Anatomy and Function
-large ruby red granules
-bilobed (horseshoe) nucleus
-helps fight parasites
-participates in allergic reactions
-numbers increase parasite infections and allergic reactions
Basophils: Function and Anatomy
-large purple granules
-bilobed (horseshoe) nucleus
-helps mediate inflammation via release of histamines (vasodilator) and heparin (anticoagulant)
lymphocytes: Function and anatomy
-pale blue cytoplasm
-large spherical purple/blue nucleus
-main function is launching an immune response
-B cells make antibodies
-T cells attack normal cells (malignant and virus infected)
-numbers increase with viral infections and leukemia
monocytes: Anatomy and Function
-largest WBC
-gray/blue cytoplasm
-large kidney shaped purple/blue nucleus
-helps fight infections by phagocytose bacteria and cell debris
-become macrophages outside of blood vessels
platelets (Thrombocytes): function and anatomy
-cell fragments; anucleate
-derived from processes of multinucleated cells in red bone marrow (megakaryocytes)
-participate in clotting process
-cell membrane contain clotting factors (enzymes) that participate in coagulation cascade
Hematopoiesis
-the process of blood cell formation
-occurs in red bone marrow
-all blood cells derive from common stem cell
1. Start with hemocytoblast stem cells
- divide into lymphoid cells and myeloid cells
2. The lymphoid cells divide into lymphocytes
3. The myeloid cells divide into erythrocytes, monocytes, neutrophils, neutrophils, eosinophils, and basophils
What hormone controls synthesis of RBCs
-erythropoietin which is secreted by the kidneys
-decreasing oxygen levels = increasing erythropoietin
How are red blood cells formed
- Stimulus (low blood O2- carrying ability due to decreased RBC count, decreased amount of hemoglobin, and O2)
- kidney (some liver) release erythropoietin
- Erythropoietin stimulates red bone marrow
- Enhanced erythropoiesis increases RBC count
- O2 carrying ability of blood increases
What is blood plasma made of?
-composed of 90% H2O
-solutes include nutrients (glucose)
-salts (electrolytes)
-respiratory gases (O2 and CO2)
-waste (urea)
-hormones
-plasma proteins (albumin)
Albumin (Blood plasma proteins)
-made in the liver
-regulates osmotic pressure of blood
-many drugs travel in blood attach to albumin
Antibodies (plasma proteins)
-made by lymphocytes
-protein tags that attach to bacteria and abnormal cells–> target for destruction
Fibrinogen (plasma proteins)
-converted to fibrin during coagulation, is a major component of blood clots
Characteristics of blood
-average blood volume: 5-6 liters
-color range: oxygen rich: bright red
oxygen poor: dark red
-pH must remain between 7.35 and 7.45