Blood is the functional unit of the cardiovascular system.
The primary function of the cardiovascular system is to move nutrients, hormones, wastes, and other substances around the body. Blood - the liquid - is the carrier for all those.

To move nutrients and other chemicals such as hormones and cellular waste products around the body.

Blood plasma forms the MATRIX of the blood plasma!  This LIQUID matrix is the functional unit of blood plasma. 
 

What is the matrix of blood plasma? Hint: Review Chapter 4 – Connective tissues.
WATER, the liquid at room temperature, is the functional unit of blood plasma that dissolves nutrients and suspends objects such as WBCs and proteins.  With these molecules and cells suspended in the liquid, they are easily moved around the body.  As a liquid, it can flow (viscosity), and therefore MOVE from one place to another. As it moves, anything dissolved or suspended in the liquid is also moved.  This is called 'mass flow'. (We use this concept all the time in our daily lives: we put water in the toilet, then flush human waste using the water as a 'carrier' - i.e. MASS FLOW.)

What are the two main parts of blood?
  Plasma and Formed Elements.
      What are the components of Plasma?
          Plasma contains electrolytes and many different plasma proteins.
      What are the the 3 main plasma proteins, and their functions?
          Which is most abudant?
      What is serum?
What is the normal blood volume contained in the average person's cardiovascular system?

Blood Samples are taken via three basic methods:

Capillary smear: a tiny 'rupture' of the integumentary system is made, and a drop of
      blood is taken.
      Function: such things as diabetes/blood sugar, or blood typing, etc.
Venipuncture: blood is taken from a vein.  The most common vein used, is the cubital vein.
          See Chapter 1, Anatomical Landmarks - find the cubital region of the arm.
      Function: most blood tests.  Normal blood coming from the tissues contains CO2 and
         other waste products from cellular metabolism, and is low in O2.
Arterial Stick: Blood is taken from an artery, usually the brachial artery at the elbow or
         the radial artery at the wrist.
      Function: arterial blood gases.  Reveals the condition of the blood BEFORE the blood
         passes through the tissues.  Normal blood going to the tissues is 'clean' and loaded
         with O2 and nutrients.
 

What is a Venipuncture?
What is a capillary smear?
What is an arterial stick?

The venipuncture is most common for several reasons:

a.  veins are often superficial and easy to find, while arteries are usually deep.
b.  veins usually have very low blood pressure, while the BP in arteries is usually
        very high.
c.  because BP is usually low in veins, the body's ability to 'patch' the hole efficient,
         while high BP in arteries can cause problems in folks who are 'bleeders'.

Which is the most common method of obtaining a blood sample?

Hemopoiesis  - AKA Hematopoiesis - formation of blood cells
   the suffix 'poiesis' - means - 'formation of'

Hemopoiesis creates RBCs and WBCs and takes place in the red bone marrow.
Erythropoiesis creates RBCs.
Leucopoiesis creates WBCs.

What is hematopoiesis?
   Where does hematopoiesis occur?
     Which type of bone marrow?

RBCs are a biconcave disc.  They look sort of like a donut with a membrane across the hole.
       - 7 micrometers in diameter
       - ca. 5 Million per microliter of blood
       - packed with ca 250 Million hemoglobin molecules
       - NO nucleus, NO ribosomes, NO centrioles
       - NO mitochondria

RBCs normally live about 120 days because they do not have DNA or ribosomes and cannot
   produce new CM.
     The round trip from the heart to a tissue/capillary bed and back to the heart takes about 30 seconds.  The RBC makes LOTS of roundtrips per day.  Each trip, it scrapes along the walls of the vessels and through the tiny diameter of the capillaries.  This causes the CM to become frayed and worn out.
  Two ends to the RBC: 1) phagocytized or 2) rupture.

NORMALLY – the RBCs are phagocytized in the spleen and the hemoglobin is broken down into its parts and those parts are recycled. 
(Phagocytosis can also occur in the Liver and in Bone Marrow).
Hemoglobin is broken down to
    - globin (a protein) - which is then broken down into its amino acids
    - Fe is stripped from the heme molecules and either stored in the phagocyte in the spleen, or in
          the liver, or it is shipped to the bone marrow and used in erythropoiesis.         
    - heme is metabolized and becomes
                 biliverdin, which goes to the liver and is metabolized to form
                   bilirubin which is metabolized to form
                      Bile - which is stored in the gall bladder and then dumped into the small intestine
                          and used to digest fats, or excreted in waste (gives feces the normal brown color).

The RBC can also RUPTURE in the blood vessel.  This is NOT normal and causes problems,
   one of which is hemoglobinuria which is hemoglobin in the urine.

  NOTE - this is HEMOGLOBIN in the urine.

People occasionally have 'blood in the urine' -
     What does this mean?
It can mean either hemoglobinuria OR more commonly hematuria.
Hematuria is RBCs (the actual CELL) in urine and is caused most often by a
       UTI (urinary tract infection).
   NOTE: hematuria has nothing to do with the RBC life cycle.

What is the function of the Spleen?
    Macrophages in the spleen clean the blood, specifically of old RBCs, but also of any other
       debris or foreign matter that may be present.

List all the blood types.

There are 4 blood types (that we study in this class)

Blood type depends on the Antigens present on the surface of the RBCs.  Antigens are IDENTIFIER proteins that ID the cell as either a self (belongs in your body) or a foreign cell (is an invader). 

Type A has the A surface antigen; B has the B surface antigen and so on.
The blood PLASMA contains various blood proteins, including the globulins.  Globulins are antibodies (proteins)  whose function is to detect foreign cells. 
   - A person with the A blood type also has antibodies in the blood plasma that detect the B type
         surface antigens. 
   - A person with B blood type also has antibodies in the plasma that detect A type surface antigens.

What type surface antigens are found on O blood type?
What type antibodies are found in the plasma of O blood type folks?
What type surface antigens are found on AB blood type?
What type antibodies are found in the plasma of AB blood type folks?

When the plasma antibodies detect a foreign blood type, the antibodies bind to the foreign antigen, and cause the foreign RBCs to agglutinate (coagulate, clump, clot). Ideally, macrophages would come along and phagocytize the clot before it gets too big and becomes an embolus.
     Embolus - A mass of anything floating freely in the blood: oil/fat, clotted RBCs, piece of any
        tissue, air bubble, etc.  This 'mass' can get lodged at the entrance to a capillary bed and cut off
        blood flow into that capillary bed.
 
However, putting a LARGE amount of RBCs with the 'wrong' blood type into a person results in massive CLOTTING which then causes multiple problems, including pulmonary embolisms.
     Pulmonary embolism - an embolus that blocks blood flow through the pulmonary capillary beds.
        Can lead to CHF (congestive heart failure) and death.

O blood type is the Universal Donor - Since O type RBCs do NOT have surface antigens, these
      RBCs can be transfused into any of the other blood types.
AB blood type is the Universal Acceptor - since it does not have either plasma antibody and can
      accept blood from ANY blood type.
 

Rh-factor is an antigen (a protein) located on the surface of the RBC.  This antigen was first discovered in Rhesus monkeys and named Rh-factor after Rhesus.  It is either present (+) or it is not (-).
    A person who has the Rh-factor is termed (+)
    A person who does NOT have the Rh-factor is termed (-).

A person with A+ blood type has A type surface antigens, and the Rh-factor.
A person with O- blood type does NOT have any surface antigens, NOR the Rh-factor.

Blood donations are centrifuged and the whole blood separated into RBCs and Plasma.
Blood transfusions therefore consist only of RBCs.  There is very little plasma (with antibodies) in the transfused blood cells.  The few antibodies in the plasma are quickly denatured by the blood of the recipient.
There ARE instances where folks are given plasma - but this is only done under specific circumstances, such as when a person is hemorrhaging and needs clotting factors.
If a person just needs an increase in blood volume to maintain blood pressure, he is usually given either 'normal saline solution, or 'normal' sugar solution.

WBCs have 4 characteristics:
   Amoeboid movement - can move around on their own power.  They are self propelled, moving along
       in the same manner as do the microbe - amoeba.
   Diapedesis - can squeeze into the spaces between cells and 'chase' bacteria through the
       extracellular fluid.
   Chemotaxis - can respond to 'chemical signals' (prostaglandins) that tell the WBC to
         either 'come here' or 'stay away'.
   Phagocytosis - when they encounter a foreign cell or molecule, or fragments of cells and tissue,
        WBCs can 'eat' it.

List the 5 types of WBCs (Make a table for comparisons):

Eosinophil - phagocyte; Nonspecific defense
Neutrophil - phagocyte; nonspecific defense
Basophil - histamine and heparin; nonspecific defense;
              Remember MAST cells?
Monocyte - phagocyte, chemotaxis; nonspecific defense

Lymphocyte - SPECIFIC DEFENSE - immune system, immune response
   3 types of cells
       NK cells - Natural Killer cells - surveillance of tissues looking for abnormal self cells, and
               anything else that doesn't belong
       T-cells - Phagocytes
       B-cells - mitosis to produce Plasma cells which produce Antibodies.

WBCs function for Specific or Nonspecific defense

Hemostasis – the process of preventing loss of blood through damaged vessel walls -
     in other words forming Blood clots.

Platelets, aka Thrombocytes, are small, membrane-bound packets of cytoplasm with clotting enzymes and factors.  A cell called a Megakaryocyte, pinches off bits of cell membrane that encloses some cytoplasm, clotting factors and enzymes - which are called platelets.
   How are platelets produced?

Clot formation requires Ca++, Vitamin K, and other clotting factors as well as enzymes to control each chemical reaction in the clotting process.
What mineral and vitamin are used in the clotting process?

Blood clotting occurs in 3 stages:

Vascular phase - this is the first step.  The cells that make up the wall of the vessel become
      sticky and stick together.  In SMALL wounds (capillaries), this may be sufficient to 'patch'
       the hole.
Platelet Plug phase - the cells that make up the walls become sticky, Platelets in the area
      become sticky.  The cells stick to each other, the Platelets stick to the sticky cells - this
      form a patch that seals the wound.  This is efficient in medium size wounds, especially in
      veins where blood pressure is low.
Clot formation phase - this is the mother of all patches.  Not only do the cells of the vessel
      wall and platelets become sticky and start stickin to one another, Fibrinogen
      metamophoses into Fibrin, which is the STICKY, functional form of the protein, and sticks
      to the sticky platelets and cells, and any other cells (such as RBCs) in the neighborhood.

Fibrinogen is the third of the three blood proteins mentioned earlier.  Fibrinogen is 'activated' to
   become Fibrin.
Fibrin is a rope like molecule that 'binds' the components of the clot to each other. This like using a
    rope to tie down a load on a truck.  Many fibrin molecules run THROUGH the clot rather than just
    over the surface.

The cells, platelets and fibrinogen become 'sticky' in sequence due to the actions of a series of enzymes and clotting factors.  The first few clotting enzymes and factors cause the cells to become sticky, the second set cause the platelets to become sticky... and so on to fibrinogen.
The FIRST clot usually forms OUTSIDE the vascular system, and builds a patch on the outside of the vessel wall.  This prevents the build up of a potential 'embolus' inside the vascular system.  If the wound is large, a secondary patch will be constructed inside the vascular system.

Fibrin holds the clot together.  Clot retraction (removal of the clot, control of the absolute size of the clot) begins almost immediately. 

Tissue Plasminogen Activator (t-PA; used to treat stroke victims) activates Plasminogen to become Plasmin - a functional enzyme - to break down fibrin.  Plasmin 'cuts' the fibrin into small pieces, which allows the clot to be dissolved, one piece at a time.  This prevents the formation of emboli.

Production of Blood cells slows and may become less efficient.
WBCs may start recognizing 'normal' cells and tissues - and eating them.

Remember – all the systems have to work together to maintain homeostasis.
  What is the main function of blood?
    How does this function affect other tissues?

The suffix ‘-emia’ refers to blood. Septicemia, anemia, leukemia, hypercalemia, etc. are all diseases of the blood.

IN GENERAL, be able to recognize:
      a RBC
     

WBC

IN GENERAL, be able to recognize:
   Neutrophil
   Eosinophil
   Basophil
   Monocyte
   Lymphocyte