Chapter 13 Part I: Blood Flashcards
Blood
Transports foods, gases, and wastes to and from the cells of the body.
Other transported items:
- Chemical messengers
- Blood proteins, white blood cells, and platelets
Primary Functions of Blood
- Maintains a constant environment for the other living tissues.
- Transports nutrients (digested food particles from Gl), gases (O2, CO2), waste (urea) to/from body cells.
- Transports chemical messengers (hormones) from the sites of their secretion to distant target/regulatory sites.
- Contains proteins (clotting factors), WBC, RBC, antibodies, platelets (thrombocytes).
Composition of Blood
- Cells
- Plasma
- Water
- Proteins
- Sugar
- Salts
- Hormones
- Lipids
- Vitamins
Composition of Blood
- Blood is composed of cells (45% of the blood volume) suspended in a clear liquid called plasma (55% of the blood volume with 90% water).
- 45%: These cells include erythrocytes (RBC), leukocytes (WBC) and platelets/thrombocytes (clotting cells).
- 55%: Plasma which is a solution of water, proteins, sugar, salts, hormones and vitamins.
Erythrocytes
Red blood cells transport nutrients and oxygen.
Leukocytes
White blood cells.
Thrombocytes
Platelets; clot blood.
Types of Leukocytes: Basophils
Contain heparin (prevents clotting) and histamine (involved in allergic responses).
Types of Leukocytes: Eosinophils
Phagocytic cells involved in allergic responses and parasitic infections.
Types of Leukocytes: Neutrophils
Phagocytic cells that accumulate at sites of infection.
Types of Leukocytes: Monocytes
Phagocytic cells that become macrophages and digest bacteria and tissue debris.
Types of Leukocytes: Lymphocytes
Control the immune response; make antibodies to antigens.
Hematopoiesis
• Blood cells originate in the bone marrow cavity of bones.
• Both RBC & WBC arise from hematopoietic stem cells (hematopoiesis). These stem cells further change their shape/size to become specialized (differentiated, mature cells).
Plasma proteins
- Albumin
- Globulins: immunoglobulins (IgG, IgA, IgM, IgD, IgE)
- Fibrinogen
- Prothrombin
RBC (Erythrocytes)
Loses nucleus and assumes a biconcave disk shape that resembles a cough drop that allows for a large surface area to reabsorb & release gases (02 & CO2).
Erythrocytes
• Contains hemoglobin (heme + globin).
• Hg enables RBC’s to carry
O2 and this combination (oxyhemoglobin) produces the bright red color of blood.
• Erythropoietin (EPO, hormone) from the kidney stimulates RBC production in the marrow.
Erythrocytes Cont.
• Life span: ~100-120 days.
• Macrophages (in the spleen, liver, bone marrow) destroy old RBC’s (hemolysis) causing heme to release iron and decompose into yellow/orange pigment called bilirubin (jaundice/icterus).
Leukocytes
- Less numerous than RBC.
- Five mature types:
- Polymorphonuclear: granulocytes (basophil, eosinophil and neutrophil).
- Mononuclear: agranulocytes.
- Lymphocytes: part of immune response with antibody production (against antigens).
- Monocytes: phagocytic cell.
Platelets
Also known as thrombocytes.
- It’s main function is to clot blood.
Plasma
Liquid part of blood containing water, proteins, sugar, wastes, salt, hormones and others.
4 Main Proteins in Plasma
- 4 main proteins:
• Albumin: maintains proper concentration of water in blood.
• Immunoglobulins (Ig): antibodies that bind to antigen & destroy them (eg. IgA found in breast milk).
• Fibrinogen and prothrombin: involved in coagulation. - Plasmapheresis (-apheresis means to remove): process of separating plasma from cells (in a centrifuge machine).
Serum
Plasma minus clotting proteins and cells.
Centrifuge Process and Formed Elements
- Withdraw blood and place in tube.
- Centrifuge the blood sample.
After the blood sample is centrifuged the formed elements from top to bottom are…
Top
- Plasma - 55% of whole blood
- Least dense component
Middle
- Buffy coat - Leukocytes and platelets
- <1% of whole blood
Bottom
- Erythrocytes - 45% of whole blood (hematocrit)
- Most dense component
Composition of Formed Elements in Blood: Plasma
Water, proteins, nutrients, hormones, etc.
