BLOOD

Learning Objectives

• Describe the primary functions' of blood

• Describe the characteristics of blood

• Discuss the blood types including Rh factor

• Describe common disorders of blood

Blood transports substances and maintains homeostasis in the body

Hematophobia= fear of blood

Blood and Blood CellsBlood is a type of CONNECTIVE TISSUE

It has two basic components:

CELLS  (rbc, wbc, platelets)  = 45%

Plasma (water, proteins, amino acids..etc)  = 55%

Hematocrit - volume of blood cells in a sample, should be 45%. The remaining fluid is plasma (55%). To determine the percentages, blood is placed in a centrifuge

Three Types of Blood Cells red blood cells (erythrocytes)white blood cells (leukocytes)platelets (thrombocytes)

BLOOD

RBC live about 4 months before going to the liver

Granular leukocytes live only a few days

Non-granular leukocyte 6 months or more

Biconcave discs5 million per cubic millimeterLack nuclei

HEMATOPOEISIS – formation of blood cells (bone marrow)

Liver & Spleen - phagocytosis

Main Functions of RBCs

Transports oxygen, picks up carbon dioxide

HEMOGLOBIN - molecule that combines with O2 IRON is critical to synthesize hemoglobin

Oxygen Levels

Oxyhemoglobin =         plenty of oxygen; bright red

Deoxyhemoglobin =         low in O2, “bluish red”

Elements Critical to RBC Production

• Folic Acid• Vitamin B12• Iron

Too few RBC = anemia

WHITE BLOOD CELLS(Leukocytes)

• General function is to protect the body against disease

• There are FIVE different kinds of WBCs

Granulocytes (granular cytoplasm)           Neutrophils, Eosinophils, BasophilsAgranulocytes (lacking granular cytoplasm)           Monocytes, Lymphocytes

Neutrophil (nucleus has several lobes)

Active phagocytes60% of WBC

Present in the pus of wounds

Basophil Produces Heparin and Histamines

Important in Inflammatory Reaction

1% WBC

Eosinophil

Mainly attack parasites2% WBC

Monocyte (larger cell, horseshoe shaped nucleus)

Become macro-phages

Lymphocyte(nucleus is dark and takes up almost whole cell; almost no cytoplasm seen)

Defense against invaders

Yield Antibodies30% WBC

Left: Lymphoctye | Right: Neutrophil

Platelets (thrombocytes)

Blood clots and vessel repair

Platelets

• Platelets and blood clotting Platelets play an essential role in blood

clotting Blood clot formation

Clotting factors released at the injury site produce prothrombin activator

Prothrombin activator and calcium convert prothrombin to thrombin

Thrombin triggers formation of fibrin, which traps RBC to form a clot

PLASMA

The liquid portion of blood is 92% water

Also contains nutrients, gases, vitamins (etc) and plasma proteins

Plasma Proteins

• Albumins – blood pressure• Globulins (alpha, beta, gamma) – transport

lipids and antibodies for immunity• Fibrinogen – important for blood clotting

MAJOR EVENT IN BLOOD CLOTTING =

Fibrinogen converted to FIBRIN

This machine removes the plasma from the blood and returns the RBC’s to the donor.

HEMOSTASIS

The process of stopping bleedingInvolves the coagulation and clotting of the blood to seal the site of damage

1.  Blood Vessel Spasm    Seratonin = vasoconstrictor  2.  Platelet plug formation 3.   Blood coagulationconversion of fibrinogen to fibrin

*thrombin is an enzyme that causes the conversion

THREE EVENTS IN HEMOSTASIS

Hemostasis

Blood Clot Formation Animated(Video)

2D animation Medivisual

COAGULATION  -  the thickening of blood to form a clot  (hematoma)

THROMBUS – blood clot (abnormal)

EMBOLUS – when the clot moves to another place.

 What is DVT?        Video:  Deep Vein Thrombosis

 What is a Pulmonary Embolism?

         Video:  Pulmonary Embolism       

BLOOD TYPES

On a cold day in 1667, a renegade physician named Jean Denis transfused calf's blood into one of Paris's most notorious madmen. In doing so, Denis angered not only the elite scientists who had hoped to perform the first animal-to-human transfusions themselves, but also a host of powerful conservatives who believed that the doctor was toying with forces of nature that he did not understand. Just days after the experiment, the madman was dead, and Denis was framed for murder.  From:  Blood Work: A Tale of Medicine and Murder in the Scientific Revolution

1901 - Austrian Karl Landsteiner discovered human blood groups

Even animals have blood types

Blood Type is Controlled by 3 Alleles

Alleles: A, B, O

A & B are codominant

O is recessive

4 Possible Blood Types

• Rh system Rh-positive blood

Rh factor antigen present in RBCs Rh-negative blood

No Rh factor present in RBCsNo anti-Rh antibodies present naturally in plasma

Anti-Rh antibodies appear in the plasma of Rh-negative people if Rh-positive RBCs have been introduced into their bodies

Genotypes

Consider Both Parents

Type A (genotype AA) x Type O (genotype OO)

Blood Type Antigens

Blood that has antibodies on it that is not recognized by the body will be attacked by your immune system

O is the Universal Donor

AB is the Universal Acceptor

Rh Factor

A person can either be Rh + or Rh –(positive is dominant)

Rh Factor and Pregnancy

*Problem: When a fetus is Rh+ and the mother is Rh-, this can cause the mother’s immune system to attack the fetus. There are drugs that will suppress this reaction.

Blood Type Test

Blood Safety

EXAMPLES OF BLOODBORNE PATHOGENS • HEPATITIS B (HBV)• HEPATITIS C (HCV)• Other NON A, NON B HEPATITIS• HUMAN IMMUNODEFICIENCY VIRUS (HIV)• MALARIA• OTHER POTENTIALLY INFECTIOUS MATERIALS

TRANSMISSIONHIV, hepatitis B virus, and hepatitis C virus are the viruses most likely to be transmitted via the following routes in an occupational setting:

needle stick / sharps injuries skin or eye contact mucous membrane and non-intact skin exposure to contaminated blood or other potentially infectious materials ( scratches, cuts, bites, or wounds )

Avoid Contact With Blood

• Wear gloves• Dispose of items that have been

contaminated (tissues, needles, bandaids) in biohazard containers

• Do not “horse around”• Treat every person as if they may be

carrying an infectious disease

BLOOD DISORDERS

Carbon Monoxide Poisoning

CO binds to your hemoglobin, prevents oxygen from binding.  Can be fatal.   It is a "silent killer" as people often die in their sleep when a heater fails.

Carbon monoxide deaths are more likely to occur in winter  Article from 2010, St Clair County

 

ANEMIA• Iron-Deficiency Anemia (most common)• Aplastic Anemia – bone marrow does not

produce enough RBC• Hemorrhagic anemia – due to extreme blood

loss• Pernicious anemia – B12 deficiency• Sickle Cell Anemia (genetic) -

       blood cells abnormally shaped• Polycythemia – too many RBC

SICKLE CELL ANEMIA

• Genetic Disorder

• Abnormally shaped blood cells

• Parents can be carriers (asymptomatic)

Complications

1.Pain 2.Lethargy3.Lifelong anemia

(low red blood count)4.Organ failure5.Stroke

Leukemia• Type of cancer• Overproduction of immature white blood

cells• They take the place of RBCs

• Treatable with bone marrow transplants, chemothemotherapy, radiation

Leukemia

• Leukopenia - Abnormally low WBC

• Leukocytosis – Abnormally high WBC count

• Leukemia – Elevated WBC, but they do not function properly – immature

Blood Smear of a patient with Leukemia

Blood Smear; Leukemia

Leukemia is one of the most common childhood cancers. It occurs when large numbers of abnormal white blood cells fill the bone marrow and sometimes enter the bloodstream.

Because these abnormal blood cells are defective, they don't help protect the body against infection the way normal white blood cells do. And because they grow uncontrollably, they take over the bone marrow and interfere with the body's production of other important types of cells in the bloodstream, like red blood cells (which carry oxygen) and platelets (which help blood to clot).

St. Jude Hospital

Infectious mononucleosis sometimes called "mono" or "the kissing disease," is an infection usually caused by the Epstein-Barr virus (EBV).

The designation "mononucleosis" refers to an increase in one type of white blood cells (lymphocytes) in the bloodstream relative to the other blood components as a result of the EBV infection.

EBV is very common, and many people have been exposed to the virus at some time in childhood.

 Article at Medicinenet

  

Blood poisoning - Septicemia

• An infection enters the blood stream• Can be deadly• Treated with antibiotics

Thrombocytopenia

• Low production of Platelets• Causing bleeding or bruising

A bruise is caused when tiny blood vessels are damaged or broken as the result of a blow to the skin (be it bumping against something or hitting yourself with a hammer).  The raised area of a bump or bruise results from blood leaking from these injured blood vessels into the tissues as well as from the body's response to the injury.

Hemophilia - inability or reduced ability of the blood to clot; genetic disorder (more on this later)

von Willebrand Disease - also a clotting disorder, but not as severe, excessive bruising occurs

HEMOPHILIA

This disorder causes a failure of the blood to clot

Patients can be treated with blood transfusions that include clotting agents.

Queen Victoria

Carrier for Hemophilia

Jaundice• In newborns, caused by the liver not

functioning fully• Secretes bilirubin into the blood causing

the yellow color• Exposure to flourescent lights (bili lights)

will break down the substance

Quick Genetics ReviewA gene consists of 2 alleles (represented by letters)One allele is usually dominant over the other Example: Genotype     PhenotypePP            widow’s peakPp             widow’s peakpp          straight  hairline

A person with a widow's peak (Pp) is married to a person with a straight hairline (pp), what percentage of their children will have a straight hairline?

Two people who are both heterozygous for the widow's peak trait are married. What percentage of their children will have a straight hairline?

Sickle Cell Anemia is actually codominant

AA = normalAa = sickle cell trait (few symptoms)aa = sickle cell anemia

If both parents are carriers, child has a ¼ chance of having the disease

A female has sickle cell anemia and is married to a man who appears normal.  A doctor tests the man and determines that he does NOT have sickle cell trait.  What is the chance that this couple will have a child with sickle cell anemia?

What happens when a female who is a carrier marries man with sickle cell anemia?

Hemophilia is carried on the X chromosome

Females X H X H normal

X H X h carrier

X h X h hemophiliac

Males X H Y normal

X h Y hemophiliac

What happens when a female who is a carrier marries a normal man?

What happens when a female who is normal marries a man who has hemophilia?