Universal Precautions for Bloodborne Pathogens

• Blood, a connective tissue, transports nutrients, oxygen, wastes, and hormones, maintaining stability of interstitial fluid and distributing heat.
• Blood links the body's internal and external environments.

Universal Precautions

• Blood contains cells, nutrients, proteins, and water and a single drop can contain billions of viruses from an infected individual
• In 1988, the CDC created "universal precautions" following the AIDS epidemic for health workers to prevent transmission of bloodborne infections.
• The CDC identified HIV and hepatitis B virus.
• The term “universal” assumes any patient could be exposed to a pathogen transmittable via bodily fluids.
• 4-7% of new infections globally are from unsafe injections, according to WHO estimates.
• Recommendations include personal protective equipment (gloves, goggles, masks).
• Engineering and work-practice controls such as fume hoods, sharps containers, and handwashing are essential.
• Universal measures might not be enough for outbreaks because of the copious and infectious nature of body fluids

Introduction to Blood

• Blood consists of cells, cell fragments, and dissolved biochemicals essential for life.
• Blood transports nutrients, oxygen and hormones
• Blood helps remove waste products
• Blood helps stabilize interstitial fluid
• Blood helps distribute heat
• Blood links the body's internal and external environments to promote homeostasis

Blood Composition

• Blood cells form mostly in red bone marrow
• Blood cells transport gases and fight disease.
• Blood platelets help control blood loss.
• Formed elements include cells and platelets
• Plasma is the liquid portion, with about 45% red blood cells (hematocrit).
• The remaining 55% is plasma, a clear, straw-colored liquid of water, amino acids, proteins, carbohydrates, lipids, vitamins, hormones, electrolytes, and cellular wastes.
• Blood volume varies with body size, fluid/electrolyte levels, and adipose tissue, averaging 5 liters (5.3 quarts) in adults.

Red Blood Cells

• Red blood cells (erythrocytes) have a biconcave shape that is ideal for gas transport and increases surface area
• Red blood cells lack nuclei and mitochondria and therefore cannot synthesize proteins or divide

Hemoglobin

• Red blood cells contain hemoglobin which binds to oxygen
• Hemoglobin is about one-third volume of a red blood cell.
• Oxyhemoglobin is formed when hemoglobin binds oxygen and is also bright red
• Deoxyhemoglobin is formed when oxygen is released and is also darker
• Hypoxia causes cyanosis, a bluish skin discoloration, due to high deoxyhemoglobin.
• Low temperatures may also cause cyanosis through constricting blood vessels

Red Blood Cell Count

• The red blood cell count (RBCC or RCC) is the number of red blood cells per microliter (µL) of blood.
• Typical RBCC ranges from 4,700,000 to 6,100,000 cells/µL for adult males and 4,200,000 to 5,400,000 cells/µL for adult females.
• Red blood cell counts are used to assess health and diagnose diseases since changes in this number can affect health

Red Blood Cell Production

• Red blood cell formation (erythropoiesis) first occurs in the yolk sac, liver, and spleen, then primarily in red bone marrow after birth.
• Hematopoietic stem cells or hemocytoblasts facilitate red blood cell formation
• The average red blood cell lifespan is 120 days
• Erythropoietin, a hormone, controls red blood cell formation rate, through negative feedback.
• The Kidneys release erythropoietin in response to low oxygen to then trigger red bone marrows and stimulate red blood cell production
• After a few days, a rapid increase in the number of erythrocytes in the circulation is sufficient to supply tissues with oxygen.
• The production rate returns to normal when oxygen availability is normal
• Polycythemia is a condition that increases blood viscosity, slows blood flow and impairs circulation.

Dietary Factors of Red Blood Cell Production

• Vitamin B12 and folic acid are required for DNA synthesis, so a deficiency especially affects blood-forming tissue during rapid cell division.
• Hemoglobin synthesis and normal red blood cell production needs iron due to reusing iron from hemoglobin decomposition

Red Blood Cell Destruction

• Macrophages phagocytize and destroy damaged red blood cells in the liver and spleen.
• Hemoglobin molecules break down into polypeptide chains and heme groups.
• Heme decomposes into iron and biliverdin (greenish pigment).
• Reused Iron transports to hematopoietic tissue where new hemoglobin is synthesized
• Biliverdin converts to bilirubin (orange pigment) and is then secreted in bile

Other Red Blood Cell Conditions

• Anemia is the condition resulting from a deficiency of red blood cells or hemoglobin that reduces the oxygen-carrying capacity which causes the person to lack energy
• Hemochromatosis is an inherited disorder in which the small intestine absorbs iron at ten times causing iron to build up in organs, to toxic levels
• Periodic blood removal can be as often as every week to treat it
• Sickle cell disease is when a DNA mutation changes one amino acid in hemoglobin protein and low oxygen causes the hemoglobin to crystallize.
• The red blood cells containing the abnormal hemoglobin then bend into a sickle shape, which then block blood vessels causing pain and organ damage.
• Hydroxyurea is a drug which activates production of fetal hemoglobin is used to treat sickle cell disease.
• A bone marrow transplant or an umbilical cord stem cell transplant can cure the condition

Summary of White Blood Cells

• White blood cells (leukocytes) protect against disease.
• White blood cells and develop from hematopoietic stem cells in the red bone marrow
• Hormones stimulate the development of the precursor cells.
• The hormones are classified as either interleukins or colony-stimulating factors.
• While interleukins are numbered, most colony-stimulating factors are named for the cell population they stimulate.
• White blood cells transport to sites of infection and may leave the bloodstream.

Types of White Blood Cells

• The five types of white blood cells circulating commonly in the blood differ in size, cytoplasmic nature, nuclear shape, and staining traits.
• Granulocytes have granular cytoplasm include neutrophils, eosinophils, and basophils. They develop in red bone marrow.
• Agranulocytes are without cytoplasmic granules lymphocytes and monocytes form from red bone marrow
• Neutrophils have fine, light purple cytoplasmic granules and a lobed nucleus.
• Eosinophils have coarse, uniform, deep red granules that appear in acid which is bilobed
• Basophils have fewer, irregular deep blue granules and are smaller
• Monocytes are the largest blood cells and have varied nuclei shapes
• Lymphocytes are slightly larger than red blood cells and have large nuclei and are small
• Lymphocytes are formed from lymphatic system

White Blood Cell Functions

• White blood cells protect against infection.
• Leukocytes phagocytize bacterial cells or produce antibodies which disables foreign particles
• Diapedesis is the movement that allows Leukocytes to squeeze between blood vessels cells, , leaving circulation.
• Amoeboid motion is the self-propulsion which Leukocytes use and monocytes become macrophages that phagocytize bacteria, dead cells, and debris.
• Neutrophils ingest particles which are small
• Eosinophils weakly phagocytic that and they also kill certain parasites
• Basophils release heparin, which inhibits blood clotting, and histamine to promote inflammation and increasing blood flow.
• Lymphocytes are important in immunity.

Different White Blood Cell Count

• White blood cell count (WBCC) is the number of white blood cells in a microliter of blood, normally 3,500-10,500 cells.
• Leukocytosis is a total exceeding 10,500 per microliter, indicates acute infection.
• greatly elevated count indicates a leukemia.
• Leukopenia is A count below 3,500 per microliter which may accompany typhoid fever, influenza, measles, mumps, chickenpox, AIDS, or poliomyelitis
• Differential white blood cell count (DIFF) is the percentage of the types of leukocytes in a sample.
• The test is useful because the ratios of white blood cells may change in particular diseases
• Neutrophils usually will increase during bacterial infections
• Eosinophils may become more abundant during parasitic infections.
• The type of lymphocytes in an amount will drop during AIDS.

Blood Platelets

• Platelets (thrombocytes) assist in closing breaks in damaged blood vessels, as section 12.4 explains on page 339
• Platelets (thrombocytes) are cell fragments forming from red bone marrow cells called megakaryocytes that release the fragments into circulation.
• Megakaryocytes, and therefore platelets, develop from hematopoietic stem cells

Platelet traits

• Each platelet lacks a nucleus
• Platelets are able to conduct amoeboid movement
• The lifespan is roughly ten days.
• The platelet count is 150,000 to 350,000 per microliter.

Blood Plasma

• Plasma is a clear, straw-colored liquid with cells in suspension.
• Water makes up approximately 92% and there is an assortment or organic and inorganic biochemicals in it
• Plasma transports gases, nutrients, and helps regulate fluid and electrolyte balance with a favorable pH.

Plasma Proteins

• Plasma proteins are the most abundant solutes and stay in interstitial fluids, not used as energy.
• The plasma proteins include albumins, globulins, and fibrinogen which differ and function to help determine plasma
• Albumin makes up 60% are created in the liver which in turn determine the pressures of plasma
• Large plasma proteins are impermeant that create osmotic pressure.
• Colloid osmotic pressure maintains and regulates water movement between blood.
• Edema is Swelling in plasma protein which may be the response to being deprived of a diet.

Globulins and Fibrinogen

• Globulins, make up 36% of plasma which can be split into alpha, beta, and gamma.
• Synthesized Alpha/beta produced in liver which transport lipids and more
• Gamma come from lymphatic tissue to produce antibodies see (chapter 14, p. 401).
• Fibrinogen constitutes about 4% of the plasma proteins
• Fibrinogen helps with blood clotting see (section 12.4 on page 340)
• Liver origin and is the greatest protein of all plasma proteins

Gases and Nutrients

• The major gases are oxygen and carbon dioxide.
• Plasm also has a considerable amount of nitrogen, with no current significance.
• Nutrients in the plasma. include amino acids, sugars an nucleotides from the digestion tract.
• The plasma delivers glucose from the small intestine to the liver to store or even use fat if required
• Hypoglycemia can have its blood glucose broken if at normal range

Nonprotein and Plasma Electrolytes

• Absorbed Amino acid are taken to where the liver can manufacture and use them as an energy source
• The plasma contains lipids, phospholipid, cholesterol and it also contains 92% of water.
• Lipids join to become water-soluble
• Nonprotein nitrogenous consist of Molecules are consistant of nitrogen but not proteins.
• Plasma electrolytes include absorption from the intestine and byproducts of metabolism.
• Blood plasma is consistency of electrolytes that derive by their own, they consist by regulation.

Hemostasis

• Hemostasis stops bleeding which is important upon the occurance of blood vessel damages.
• Several action help control this when this action take place.
• Cutting and breaking of a small blood vessel which increase the stimulation of spasms with in of the blood vessel
• The loss of blood almost immediately with this action.
• Though it is just for a few minutes it will continue to thirty if with a block.
• a blockage will for the platelet and then will stimulate clotting to reduce blood loss
• Serotonin is relapsed from this stimulation which contraction with the muscle blood vessels walls will take place

Platelet Plug Formation

• Platelets adhere to rough surfaces, like collagen in connective tissue.
• Breaking of blood vessel will result to platelets adhering to breakage.
• Platelets also have each other which cause formation with in the vessel
• Broken areas can be contain by a quick plug, large breaks require coagulation

Blood Coagulation

• Effective is that Blood coagulation can create a clot.
• Forming in a process and actions that take an active role that result reaction
• With out a doubt whether the blood clot their is a negative balance than.
• Biochemical actions like coagulation depend or in balance.
• Without coagulation then is usually prevail

Main factor

• Biggest and main of the event in blood clot is the conversion of fibrinogen, or soluble plasma creating the insoluble fibrin of the protein.
• Fibrin is long can have so many steps formation
• Releasing tissue thromboplastin triggers the starting actions.
• Fibrin threads stick to surfaces which are damages and create the webbing
• Is in which a clot that can prevent or stop blood loss.
• The after forming yellow liquid remaining is serum.

ABO Blood Groups

• Safe transfusions depend on types
• the ABO blood type and Rh status are determined
• A cross match of recipient serum with donor red cells is a mixture to see if the combination is compatible
• Mixing under a microscope allows to determine

Antigens

• Immune response is any molecule stimulating
• Body will attack if an antigen isn't their with the process to the immune system
• Plasma of recipient is with antigens reacts to the blood donating cells

Genetics of Blood

• A,b, o are what determine inheritance of ABO
• DNA encoding is of ABO has an enzyme that determines A/B factor
• Antibodies for A/ B blood group will become synthesize in exposure of food and micro living things where A , B absent
• Person only with an anitgen has this
• This mix should not be in use because one can not take another of each traits
• Cells of this are not match the recipient plasma therefor can harm in transfusion

Other Blood Types

• They can be transfused just can be negative for each and can be give there own
• O blood are only can give and no to take
• People are mostly Rh than than negative so the people can have with them with this trait
• Women usually who are with a Rh group can give an accident reaction and can take medication to to harm them for a negative reaction that be fatal to the mother