Circulatory System

Circulatory System Blood is 8% of body weight 6 qts. for avg. sized person 3X more viscous than water

A few sayings about Blood • Blood cannot be washed out with blood. - Afghan proverb • Blood alone moves the wheels of history. – Benito Mussolini • The best blood will at some time get into a fool or a mosquito. - Austin O’ Malley • A pint of sweat will save a gallon of blood. - George S. Patton • “I have nothing to offer but blood, toil, tears and sweat.” – Winston Churchill • “Humor is a rubber sword - it allows you to make a point without drawing blood” • Groucho Marx “The thorn from the bush one has planted, nourished and pruned pricks more deeply and draws more blood.” - Maya Angelo

History of Blood • The ancient Greeks made the first descriptions of heart structure. • Leonardo DaVinci and his contemporaries made very explicit descriptions of the heart , arteries and veins. • By the 1650’s people knew of pulmonary circulation. • William Harvey (1628) made the first description of the process of systemic circulation. • By 1750 Harvey’s description was universally accepted in the Western world.

Functions • Transports nutrients • Transports O2 • Transports wastes • Transports hormones • Protects against disease • Regulates body temp. • Regulates fluid & salt balance

Lymphatic system returns body fluids back to circulatory system

Lymph System - Lymph empties into progressively larger lymphatic vessels which merge into the Thoracic Duct. - The lymph flows into the right and left subclavian veins in the thorax. - The lymphatic system is as a low pressure drainage system that collects a small portion of fluid from throughout the body and returns it to the bloodstream. -The lymphatic system depends on muscular movement, breathing, and simple gravity to move lymph fluid throughout the body.

Blood Components • Red Blood Cells • Buffy coat is a grayish layer of White Blood Cells and platelets • Plasma • Hematocrit is the % of RBC’s in whole blood • Normal volume is about 6 qts.

Blood Plasma • Blood plasma is a clear, slightly yellowish fluid. • It is a water solution containing digested food materials as well as the wastes from the tissues. • Plasma carries antibodies and hormones. • Plasma transports most of the waste CO2 from the tissues back to the lungs • Plasma carries salts and proteins which help in maintaining the correct osmotic balance between the blood and the tissues. • Blood serum = plasma - protein

Plasma proteins • There are three main groups of plasma proteins. • Albumins (55%) transport pigments, hormones and drugs. They help to maintain blood volume. • Globulins (38%) - gamma work as antibodies, alpha and beta transport lipids and hormones • Fibrinogen (7%) involved in clotting

Red Blood Cells • Biconcave disk • Transports O2 and some C02 • Will stack up as they move through tiny capillaries 3 to 5 days for a RBC to mature, they last for about 120 days 2.4 million prod. /sec.

Erythropoiesis • Erythropoiesis is the production of red blood cells (RBC’s) • This occurs in the red bone marrow. • In children, RBC’s are produced in the marrow of all of the bones. • In the fetus RBC ‘s are produced in the liver, spleen and lymph nodes. • The process starts with undifferentiated cells called stem cells. • The nucleus is extruded near the end of the development of the RBC.

Red Blood Cells cont. • Because they are non-nucleated they cannot repair themselves • After a while they are full of little tears and nicks • Old, damaged RBC’s are phagocytized by the liver, spleen or the bone marrow

RBC abnormalities • Anemia - reduced # of RBC’s : can be caused by diet and/or disease • Sickle cell anemia - incomplete dominance of normal blood cell with recessive sickle cell trait. • Heterozygous state seems to give resistance to malaria.

White Blood Cells • White Blood Cells (leukocytes)- defend the body against disease. • WBC’s have a nuclei and develop from stem cells in the red bone marrow. • Some mature in other organs. (lymph nodes, thymus) • WBC’s can leave blood vessels through a process called diapedesis.

White Blood Cells cont. • Two main groups are granular and agranular • They ingest foreign protein, secrete histamine, secrete heparin, secrete antibodies. • This slide shows a WBC swallowing two yeast cells.

Granular leukocytes - Neutrophils • 55-75% of the WBC pop. • Form in the red bone marrow. • Live short lives (hrs. to 4 days) • Numbers increase during infections. • Rapidly engulf foreign elements/cellular debris. • Strong enzymes in specific granules and lysosomes destroy them.

Granular - Eosinophils • 1-3% of WBC’s • Phagocytic in immune responses. • Involved in late-onset phase of asthmatic attacks. May cause damage by increasing cell permeability to allergic substances. • Limit the expression of mast cell degranulation during allergic reactions.

Granular - Basophils • 0-1% of WBC’s • Degranulate in allergic reactions, releasing histamine, serotinin, and heparin. • This induces contraciton of smooth muscle, increases vascular permeability enhancing the effects of inflammation.

Nongranular - lymphocyte • 20-45% of WBC’s • Arise from the bone marrow. • Also from lymph nodes, spleen and thymus. • 20% B cells, from bone marrow, short lived, secrete antibodies. • 70% T cells, long-lived, from thymus. May be cytotoxic, helper or suppressor cells associated with cell-mediated immunity. • Third kind is Natural killer cells

Nongranular - Monocyte • 2-8% of WBC’s • Arise in the bone marrow. • Mature in the blood (8 hrs.) • Critical in immune response • Macrophages • Destroy antigens. • Phagocytose cellular and related debris in wound healing, bone formations and other activities where breakdown occurs.

Platelets • Also called thrombocytes, are not complete cells. They are tiny fragments of membrane-enclosed cytoplasm pinched off from giant cells (megakaryocytes) in the bone marrow • They last about 10 days and they function in blood clotting

Platelets cont. • Function in physically plugging leaks in blood vessels and they also release chemicals that promote clotting • Prothrombin, Ca+2, and the platelets’ clotting factors are involved in making a clot.

Blood Types • Codominance between A,B which are both dominant over O • Rh factor important to mothers who are Rh negative and have an Rh positive child • Blood type varies with different cultures

The transfusion will work if a person who is going to receive blood has a blood group that doesn't have any antibodies against the donor blood's antigens. But if a person who is going to receive blood has antibodies matching the donor blood's antigens, the red blood cells in the donated blood will clump.

Blood Transfusion History • The first historical attempt at blood transfusion was described by the 15th-century chronicler Stefano Infessura. • Infessura relates that, in 1492, as Pope Innocent VIII sank into a coma, the blood of three boys was infused, through the mouth, into the dying pontiff. • The boys were ten years old, and had been promised money. • However, not only did the pope die, but so did the three children.

First Transfusions • The first fully-documented human blood transfusion was administered by Dr. Jean-Baptiste Denis, physician to King Louis XIV of France, on June 15, 1667. • He transfused the blood of a sheep into a 15-year old boy, who recovered. • Denis performed another transfusion into a labourer, who also survived. • The small amount of blood transfused allowed those two people to survive those events. • He transfused some calf’s blood into another person who died. • After other failures this procedure was banned in France and other European countries.

First Success • In 1818, Dr. James Blundell, a British obstetrician, performed the first successful blood transfusion of human blood, for the treatment of postpartum hemorrhage. • He used the patient's husband as a donor, and extracted four ounces of blood from his arm to transfuse into his wife. • During the years 1825 and 1830, Dr. Blundell performed 10 transfusions, five of which were beneficial, and published his results. • He also invented many instruments for the transfusion of blood. • Transfusions became more common but many people still died.

Blood Groups • In 1901 Austrian Karl Landsteiner discovered human blood groups. • Mixing blood from two individuals can lead to blood clumping or agglutination. • Landsteiner discovered that blood clumping was an immunological reaction which occurs when the receiver of a blood transfusion has antibodies against the donor blood cells. • Karl Landsteiner's work made it possible to determine blood groups (A, B, AB, O) and thus paved the way for blood transfusions to be carried out safely. • For this discovery he was awarded the Nobel Prize in Physiology or Medicine in 1930

Preserving Blood • The first transfusions had to be made directly from donor to receiver before coagulation. • In 1910 it was discovered that by adding anticoagulant and refrigerating the blood it could be stored for a period of days. • This opened the way for blood banks. • The first non-direct transfusion was performed on March 27, 1914 by the Belgian doctor Albert Hustin. • The first blood transfusion using blood that had been stored and cooled was performed on January 1, 1916.

First Blood Banks • Oswald Hope Robertson, a medical researcher and U.S. Army officer, established the first blood bank while serving in France during WW I. • The first academic institution devoted to the science of blood transfusion was founded by Alexander Bogdanov in Moscow in 1925. • Bogdanov was motivated by a search for eternal youth and the possibilities of bringing back the dead. • He believed that 11 blood transfusions had improved his eyesight and cured his baldness. • He later died after receiving some blood that was not compatible with his.

First US Blood Banks • In 1937 Bernard Fantus, at the Cook County Hospital in Chicago, established the first hospital blood bank in the United States. • In creating a hospital laboratory that preserved and stored donor blood, Fantus originated the term "blood bank". • Within a few years, hospital and community blood banks were established across the United States.

Plasma and RBC’s • In the late 1930s and early 1940s, Dr. Charles R. Drew’s discovered that blood could be separated into blood plasma and red blood cells. • The plasma could be frozen separately. • Blood stored in this way lasted longer and was less likely to become contaminated

Other Discoveries • Carl Walter and W.P. Murphy, Jr., introduced the plastic bag for blood collection in 1950. • Further extending the shelf life of stored blood was an anticoagulant preservative, CPDA-1, introduced in 1979, which increased the blood supply and facilitated resource-sharing among blood banks

Rh Factor • In 1939-40 Karl Landsteiner, Alex Wiener, Philip Levine, and R.E. Stetson discovered the Rhesus blood group system. • This was found to be the cause of the majority of transfusion reactions up to that time.

Blood Bank • Every two seconds someone in the U.S. needs blood. • More than 38,000 blood donations are needed every day. • One out of every 10 people admitted in a hospital needs blood. • Total blood transfusions in a given year: 14 million (2001) • The average red blood cell transfusion is approximately 3 pints. • The blood type most often requested by hospitals is Type O.

Blood Bank cont. • The blood used in an emergency is already on the shelves before the event occurs. • Sickle cell disease affects more than 80,000 people in the U.S., 98% of whom are African American. Sickle cell patients can require frequent blood transfusions throughout their lives • More than 1 million new people are diagnosed with cancer each year. Many of them will need blood, sometimes daily, during their chemotherapy treatment. • A single car accident victim can require as many as 100 units of blood.

Donor Eligibility • You must be at least 17 years old, weigh more than 110 pounds, and be in good general health to donate. • A healthy donor may donate red blood cells every 56 days • A healthy donor may donate platelets as few as 3 days apart, but a maximum of 24 times a year.

Donating Blood • A sterile needle is used only once for each donor and then discarded. • Blood donation is a four-step process: registration and medical history, mini-physical, donation, and refreshments. • Every blood donor is given a mini-physical, checking the donor's temperature, blood pressure, pulse and hematocrit level (red blood cells count) to ensure it is safe for him or her to give blood • The actual blood donation typically takes less than 10-12 minutes. The entire process, from the time you arrive to the time you leave, takes about an hour

Donation facts • The average adult has about 10 to 12 pints of blood in his body. Roughly 1 pint is given during a donation • All donated blood is tested for HIV, Hepatitis B and C, syphilis and other infectious diseases, before it can be released to hospitals • Information given to the American Red Cross is strictly confidential. It may not be released without your permission except as directed by law

Current Donor/Blood situation • The number of blood donations collected in the U.S. in a year: 15 million (2001) • The number of blood donors in the U.S. in a year: 8 million (2001) • The number of patients who receive blood in the U.S. in a year: 4.9 million (2001) • The volume of blood transfused to patients is increasing at the rate of 6% per year (2001) • The demand for blood transfusions is growing faster than donations

Blood donations cont. • Less than 38% of the U.S. population is eligible to donate blood • Blood cannot be manufactured — it can only come from generous donors • Shortages of all blood types usually occur during the summer and winter holidays

Shelf Life • Whole blood can be processed into red cells, platelets, plasma, and cryoprecipitate. • It is possible to donate specifically only platelets or plasma. This process is called apheresis. • Most donated red blood cells must be used within 42 days of collection. • Donated platelets must be used within 5 days of collection. • The body will replenish the elements given during a blood donation - some in a matter of hours, and others in a matter of weeks

Red Cross • The American Red Cross blood program started in 1940, under the leadership of Dr. Charles Drew. • They supply approximately 45% of the nation's blood supply. • They provide blood for patients in nearly 3,000 hospitals in the U.S. • The Red Cross makes blood available to any patient who needs it — patients are not required to find donors to replace the blood they use.

American Red Cross – cont. • 80% of the blood donations given to the Red Cross are collected at mobile blood drives. • The remaining 20% are collected at fixed Red Cross donor centers. • The American Red Cross works with over 50,000 sponsors each year to hold more than 120,000 blood drives, providing convenient locations for people to give blood

Heart • Pumps oxygen poor blood to the lungs and oxygen rich blood to the body. • It is a two-sided pump, consisting of 4 chambers. • About fist-sized • Output varies from 5 to 35L of blood/minute

Circulatory System