The Cardiovascular System

By: Alyssa Jonet

Overall blood characteristics

Components of blood:
  • Plasma 55%
  • Formed elements (cells) 45%
How much blood is in our body?
  • Blood is 8% of our total body weight.
  • Average women- 9 pints of blood in the body
  • Average man- 12 pints of blood in the body
Production
  • Red bone marrow forms all types of of blood cells except lymphocytes.
  • Lymphocytes are formed by lymphatic tissues.
What controls the production of blood?
  • Erythropoietin controls the production of red blood cells. Red blood cells start as immature cells in the bone marrow and then are released into the bloodstream after approximately 7 days.
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Plasma

Appearance and characteristics:
  • Plasma is the liquid matrix of blood, or blood minus its formed elements.
  • Plasma is 90% water and is also made up of sugar, fats, proteins, and salts.
Function
  • It helps maintain blood flow.
  • It transports blood cells throughout our body along with nutrients, wastes, antibodies, clotting proteins (7-9%), and chemical messengers.
How does it help maintain homeostasis?
  • Plasma also helps distribute heat throughout the body and to maintain homeostasis. The chemical messengers such as hormones and proteins, help maintain the body's fluid balance.
Why are people paid to donate plasma?
  • Donating plasma takes time and commitment.
  • People are provided with a modest stipend to recognize the time and travel to be a plasma donor.

How does the process work?

  • Plasma is collected through a process called plasmapheresis. Using a needle, whole blood is drawn from a vein in the patients arm. The plasma is then separated from the red blood cells and other cellular components. The plasma is then returned to the patients blood using a sterile saline solution to help the body replace the plasma that has been removed.
BioLife Plasma Services — Donation Process

Erythrocytes - Red Blood Cells

Appearance and Characteristics
  • RBCs have an unusual shape. They are a biconcave disk shape, which means the cell is "caved in" on both sides so that it is thin in the middle and thicker on the outside.
  • Red blood cells do not have a nucleus and are very flexible.
  • The total surface area of the body's RBCs is larger than a football field.
  • A cell survives for an average of 120 days.
  • They account for about 40-45% of the blood volume.
  • Production of red blood cells: Erythropoiesis
Function and maintaining homeostasis:
  • They help transport carbon dioxide. It must be carried away from cells and lungs for disposal.
  • They transport oxygen from the lungs to other cells in the body.
  1. Hemoglobin- this red pigment in the RBCs comes together with oxygen to form oxyhemoglobin that transports oxygen throughout the body. A hemoglobin test determines how much hemoglobin is in the blood.
  2. Oxyhemoglobin- Makes the transport of large quantities of oxygen to cells in the body.
  3. Carbaminohemoglobin- Hemoglobin can carry a small amount of carbon dioxide in the blood.
Hematocrit test:
  • This test indicates whether you have too many or too few red blood cells, which are conditions that can cause certain diseases.
  • Hematocrit is also called packed cell volume (PCV).
  • They take a sample of blood and put it in a device called a centrifuge that spins the blood very rapidly in a test tube. Doing that separates the blood into 3 parts: Red blood cells, other blood cells, and plasma. Then, they can determine the amount of cells in the blood.
Anemia- This is described as a number of different diseases caused by an inability of the blood to carry oxygen to the cells. It can result from inaccurate numbers of red blood cells or a deficiency in the hemoglobin of the RBCs. It effects 3.5 million Americans.
  • Hemorrhagic anemia- A decrease in the number of RBCs caused by hemorrhages resulting from accidents such as, bleeding ulcers.
  1. Solution: This is solved by identifying the source of bleeding, stopping the bleeding, and if needed, replace blood.
  • Pernicious anemia- A deficiency of RBCs that results from a failure of the stomach lining to produce "intrinsic factor" which is the substance that allows vitamin B12 to be absorbed from foods we eat. RBC numbers will decrease in the absence of intrinsic factor even if the vitamin is present in the diet.
  1. Solution: Long-term treatment requires repeated injections of vitamin B12 To maintain normal RBC production.
  • Sickle Cell Anemia- A severe and fatal hereditary disease caused by abnormal types of hemoglobin. A person can inherit only one defective gene to form a disease called sickle cell trait. The RBCs contain a small amount of a type of hemoglobin that is less soluble than normal and therefore, making the RBCs distorted. It two genes are inherited it is more severe.
  1. Solution: Treatments throughout life will help this.
  • Iron deficiency anemia- An inadequate amount of iron in the diet causing the body to not manufacture enough hemoglobin. If hemoglobin and RBC numbers fall below normal, it starts a unhealthy chain reaction: less hemoglobin, less oxygen transported, slower breakdown and nutrients, and less energy.
  1. Solution: Iron pills can treat this.
  • Hemolytic Anemia- A condition where the red blood cells are removed from the bloodstream before their life is over. The bone marrow can't make the red blood cells fast enough to meet the body's needs.
  1. Solution: The condition may go away however, if it doesn't this condition needs life-long treatment.
Polycythemia- This is a bone marrow disease which leads to an increased level of red blood cells and other cells in the blood stream.
  • Causes- Primary: It can result from internal problems with the production of red blood cells, mostly when the bone marrow is over reactive. Secondary- caused by another medical problem, such as, a lack of oxygen.
  • Treatment- You can treat this by using medicines, procedures, and other methods to help manage the disease. The treatments need to help lower the red blood cell count. A great example of this is a procedure called phlebotomy, where they remove some blood from your body and make your blood the correct thickness.
Donating blood:
  • Make sure you are hydrated, have enough iron in your system, and are relaxed.
  • The donation process from the time the patient arrives until the time they walk out, only takes about an hour. The actual process takes about 8-10 minutes.
  • The patient will have to go through registration where they will be asked for their ID, their health history, and where they have traveled recently. Then, the nurses will check their vital signs and hemoglobin levels.
  • The nurses will place a needle in the arm and start drawing blood. When approximately two pints of blood is collected, the donation is complete. The blood can last up to 42 days.
  • A single donation may help up to three people.
  • A patient can donate blood every three weeks.

Leukocytes - White Blood Cells

Appearance and Characteristics:
  • They are very large and nucleated. They are produced in the red bone marrow and function in the immune system. There are about 11,000 per cubic mm.
  • They perform phagocytosis, chemotaxis, and diapedesis.
  1. Phagocytosis- Eat foreign matter.
  2. Chemotaxis- The cells are drawn to an area by chemical release (Histamine, bradykinin, interleukins)
  3. Diapedesis- The movement of cells through vessels and tissues
Function and Homeostasis:
  • They defend the body from cancer cells that form inside the tissues and from microorganisms that have invaded the body.
  • These cells help the body stay healthy.
Five Types of Leukocytes:
  1. Granulocytes: The granules in the cytoplasm give color to the cells. These cells are short lived. There are 3 types...
  • Neutrophils- These are the most numerous (60%). They have a segmented nucleus (3 lobes). Their color is light purple and are seen in acute bacterial infections. They perform phagocytosis.
  • Eosinophils- It performs phagocytosis. It is larger that a neutrophil and stains a red/orange color. It has a bilobed nucleus and is 2% of all WBCs. It fights parasitic infections and breaks down antibody complex.
  • Basophils- This is the rarest cell of all and only 0.0004% of all the cells. It has a bilobed nucleus and stains dark blue/purple. It is involved in inflammation and secretes histamine and bradykinin. It also contains a potent anticoagulant called heparin, which helps prevent blood from clotting through the blood vessels.
  1. Agranulocytes- These are long lived and seen in chronic infections. There are two types.
  • Lymphocytes- This is the second most numerous type of cell (31%). It has a round nucleus with a cytoplasm and has a very long life. Instead of protecting the body from infections by phagocytosis, B lymphocytes secrete proteins called antibodies, which act to destroy bacteria, viruses, or chemical toxins. T lymphocytes don't produce antibodies, but instead protect the body by directly attacking virally infected or cancerous cells. This cell makes the body immune to infectious diseases.
  • Monocytes- These are the largest leukocytes. They have a kidney shaped nucleus and is highly phagocytic. They are capable of eating larger bacteria. Macrophages are specialized monocytes that grow to several times their original size after moving out of the bloodstream.
Conditions and treatments:
  • Leukopenia- This is an abnormally low WBC count (less than 5,000 per cubed mm). Many diseases may affect the immune system and decrease WBC count. One example is AIDS. Treatment: This is treated by stimulating the bone marrow and putting the patient on medicine.
  • Leukemia- This is blood cancers starting in the blood-forming cells in the bone marrow affecting the WBCs, where elevated WBC levels occur. They are identified as either acute or chronic, depending on how quickly symptoms appear. Treatments: The patient will need chemotherapy.
  • Mononucleosis- Also called the kissing disease. It can be spread through kissing, coughing, sneezing, and sharing drinks and utensils. The antibody EBV causes this disease and raises the WBC count. Most people between the ages of 15-24 get this. Treatment: The patient needs to take medications and sometimes stay on bed-rest.
  • Multiple Myeloma- This is a cancer formed by malignant plasma cells. These are found in the bone marrow and are important for the immune system. When lymphocytes respond to an infection, they mature and turn into plasma cells. Multiple myeloma is when there are multiple tumors made of plasma cells in the bones. Treatment: The patient may go through chemotherapy an blood transfusions.

Thrombocytes - Platelets

Appearance and Characteristics:

  • Platelets are produced in bone marrow and arise from the megakaryocyte. They are non-living and are pieces that broke off from the parent cell. Platelets are usually around 200-500,000 per cubic mm in the blood. They are only about 20% of the diameter of a red blood cell. The contain proteins on their surface, making them really sticky.
Function:

  • Platelets are the first to respond to injury. They are responsible for initiating a blood clot and prevent bleeding.

Homeostasis:

  • After the body receives and injury, clotting factors from both injured tissue cells and sticky platelets at the injury site form a temporary platelet plug. Then, a series of chemical reactions eventually result in the formation of thrombin, fibrin, and trapping of RBCs to form a clot. WBCs and RBCs are trapped in a fibrin mesh to stop the bleeding.
Hemophilia:

  • This is a rare genetic disorder where the blood doesn't clot because there is a lack of blood-clotting proteins. If you have this disorder, you may bleed longer than a normal person because the clotting proteins are not clotting fast enough. This might be life threatening because it can damage tissues and organs.
  • Treatment: The main treatment for this is called replacement therapy. They inject blood-clotting proteins into your veins.
Blood Thinners:

  • Coumadin or Warfarin- This reduces the formation of blood clots. It also is used to prevent heart attacks, strokes and blood clots in veins and arteries.
  • Heparin- This is used to prevent blood clots in the blood vessels before or after surgery or during medical procedures. It also helps with lung, blood, and heart disorders.
  • Asprin- This is used to treat pain and reduce inflammation. It's also used to prevent heart attacks, strokes, and chest pain. It is used to prevent blood clots and platelets sticking together.