8.3 Blood,tissue fluid and lymph Flashcards
what are the components of blood
plasma, glucose, amino acids, large plasma proteins and hormones, red blood cells and white blood cells and platelets
whats plasma
a yellow plasma that carries compounds dissolved in it eg. glucose and amino acids
what are platelets
fragments of large cells called mega karyocytes found in red bone marrow, there involved in the clotting mechanism of blood
what are the functions of blood
-transport O2 to and CO2 from respiring cells
-digested food from the small intestine
-nitrogenous waste from cells to excretory organs
-chemical messages (hormones)
-food molecules from storage components to the cells that need them
-platelets to damaged areas
-cells and antibodies involved in the immune response also maintain body temp and acts as buffer so no pH changes
what is blood made up of percentage volume wise
55% plasma
45% erythrocytes (RBC), platelets (blood clotting) and leucocytes (WBC)
what are the main three large plasma proteins and what do they do
- albumin (maintains osmotic potential of blood)
-fibrogen (blood clotting)
-globulin (transport and immune system)
how is tissue fluid formed
Blood flows into the capillary due to higher hydrostatic pressure than oncotic pressure in the arteriole end.
The high pressure forces fluid out of the capillary and it fills the space between the cells and is now tissue fluid
what is oncotic pressure
the tendancy of water to move into the blood by osmosis
what is hydrostatic pressure
the pressure the blood is under from the surge of blood that occurs every time the heart contracts
whats tissue fluid composed of
the same as plasma but without erythrocytes and large plasma proteins and only a few WBC
why are there no large plasma proteins in tissue fluid
they are too big to leave the capillaries
how does tissue fluid return to the blood
as the oncotic pressure remains the same along the capillaries nearer the venous end of the capillaries its higher than the hydrostatic pressure so water moves back into the capillaries by osmosis
how is lymph formed
some tissue fluid doesnt go back into the capillaries but instead enters the lymphatic system where its known as lymph
whats the composition of lymph like
similar to plasma but no erythrocytes or large plasma proteins they also have less oxygen and nutrients but it also contains fatty acids which have been absorbed into the lymph from the villi of the small intestine and little glucose
what do lymphocytes produce
antibodies
