Blood circulates throughout the body,fluid from the blood leaks into tissue.
A network of vessels known as the lymphatic system collects the fluid and returns it to the circulatory system.
LYMPH – loss fluid- a transparent yellowish fluid and is collected in lymphatic capillaries and moves to larger lymph vessels like veins lymph vessels contain valves to prevent backflow of lymph,Lymph vessels from a one-way system that returns fluids collected in tissues back to the bloodstream
These lymph vessels pass through small bean –shaped enlargements called lymph nodes- which acts as filters and producers of special white blood cells called lymphocytes that are specialized to fight infection.
The fluid is returned to the circulatory system at an opening in a vein located under the left clavicle or collarbone just below the shoulder.
Is a connective tissue that constitutes the transport medium of the circulatory systems.
TWO MAIN FUNCTIONS:
1. transport nutrients and oxygen to the cells and carry carbon dioxide and waste materials away from the cells
Blood is a type of liquid connective tissue that has many functions. It is composed of a liquid medium and blood solids. The liquid makes up to about 55 % of the blood, and blood solids make up the remaining 45 %
Blood transport nutrients,dissolved gases enzymes,hormones, and waste products.
Blood regulates body temperature,ph and electrolytes.
It protects the body from invaders and blood restricts the loss of fluid
Our bodies contain 4 to 5 liters of blood.
55% of blood is made up of a liquid portion called plasma( straw- colored liquid portion of blood and is 90% water and 10% dissolved fats, salts,sugars, and proteins called PLASMA PROTEINS.
THREE TYPES OF PLASMA PROTEINS
1.ALBUMINS – help regulate osmotic pressure
( maintain normal blood volume and blood pressure.) Most abundant plasma protein.
2.GLOBULINS OR ANTIBODIES – include antibodies that help fight off infection. Antibodies initiate the destruction of pathogens and provide us with immunity.
3. FIBRINOGEN – responsible for the ability of blood to clot.
BLOOD CELLS OR SOLIDS
The cellular portion of blood make up the other 45% and includes several types of highly specialized cells and cell fragments,they are red blood cells,white blood cells and platelets.
RED BLOOD CELLS
Are most numerous of the blood cells.One microliter of blood contains 5 million rbc’s.
Are biconcave or shaped so they are narrower in the center than along the edges.
Are produced from cells in the bone marrow they are gradually filled with hemoglabin which forces out the nucleus and other organelles.
Mature RBC do not have cell nucleus and organelles. The mature RBC becomes liitle more than a membrane sac containing hemoglabin
Is the iron-containing protein that gives RBC the ability to carry hemoglabin.
RBC stay in circulation for about 120 days fefore they are destroyed by special WBC in the liver and splee. RBC in your body are dying and being replace at a rate of 2 million per second.
Outnumbered by RBC almost 500 to 1
WBC are produce in the red bone marrow,the lymph nodes and the Spleen. Tey are larger than RBC amost colorless and do not contain hemoglabin.
WBC have a nucleus and can live for many months of years.
Main function of WBC - is to protect the body against invasion by foreign cells or substances.
WBC called phagocytes. Can destroy bacteria and foreign cells by phagocytocis( ENGULGED AND DIGESTED)
PLATELETS AND BLOOD CLOTTING
Platelets are not cells they are tiny fragments of other cells that were formed in the bone marrow.
Are formed when small pieces of cytoplasm are pinched off the large cells in the red bone marrow called MEGAKARYOCYTES. Which are found in the bone marrow,Platelets lack a nucleus and their life span is about 7 to 11 days.
Platelets play an important role in blood clotting
Help the clotting process by clumping together and forming a plug at the side of a wound and then releasing proteins called clotting factors.
Clotting factors start a series of chemical reactions that ends with a sticky meshwork of fibrin filaments that stop bleeding by producing a clot.
A genetic disoder of clotting factors is called hemophillia,suffers may bled uncomfortably from even a small cut or scrape.
Clotting blood in vessels can block the flow of blood, if this happens in the brain,brain cells may die, causing stroke.
Blood type is determined by the type of ANTIGEN present on the surface of RBC.
ANTIGEN – is a protein or carbohydrate that acts as a signal,enabling the body to recognize foreign substances in the body.
BLOOD TYPE A, B , AB , O
An individual RBC may carry an A antigen both A and B antigens ,or no antigen at all. These antigen are called blood types A,B,AB, O respectively
Type AB is known as universal receiver meaning they can receive any type of blood.
An antigen that is sometimes on the surface of the RBC is the RH FACTOR,named after the rhesus monkey in which it was discovered.
85% of the US population is RH –positive meaning an antigen are present. People who do not have RH Antigens are called RH –Negative
If an RH persons receives a transfusion of blood that has RH + antigens,RH antibodies will react with the antigen and agglutination (CLUMPING ) will occur.
The rh is the reasons there are blood test before marriage.the most serious problem with RH incompatibility occurs during pregnancy.
If the mother is rh – and the father is rh+ the child may inherit the dominant rh+ ALLELE (gene) from the father.
If the babies rh+ blood gets into the mother during delivery the mother will develop antibodies to the rh factor.
If a second rh+ Childc conceived later,the mother antibodies can cross the placenta and attack the blood to the fetus. This condition is ERYTHROBLASTOSISFETALIS.
To prevent this condition an rh mother of an rh+ Child can by given antibodies to destroy and rh+ cells that have entered her bloodstream from the fetus.
The antibodies called rhogam,may be administered to the mother within three days after the birth of her first rh+ CHILD to remove from her bloodstream any rh + ANTIBODIES.
By destroying any rh+ Cells in her bloodstream any danger to a second child is prevented because the mother will not make any antibodies against the blood cells of the rh+ fetus.