The Haematic System

Blood is a specialised biological fluid (technically a …….…………...) consisting of red blood cells
(also called RBCs or …….…………...), white blood cells (also referred to as …….…………...) and …….…………...
(or thrombocytes) suspended in a complex medium known as blood …….…………..., which is the liquid
component of blood. Plasma makes …….…………... about 55 per cent of the total blood …….…………..., is
colourless or yellowish in colour and contains the plasma …….…………... (albumins, globulins, and
fibrinogen), gases, nutrients, salts, hormones and waste products. A product of plasma which does
not contain fibrinogen is referred to as …….………….... RBCs are disc-like structures, …….…………... on
both sides. The main function of leukocytes is to protect the body …….…………... invasion of bacteria
and they are classified into two groups: …….…………... and …….………….....

The most numerous cells in the blood are red blood cells. They contain …….…………... which, when
oxygenated, gives blood its red colour. Its iron-containing part provides the transport of oxygen
and carbon dioxide. White blood cells help resist infections, and platelets are important in the
…….…………... of blood, also called blood clotting. Blood circulates round the body via blood
…….…………... by the pumping action of the heart. Medical terms related to blood often begin with
haemo- or haemato- (US: hemo- and hemato-), from the Greek word haima for blood. Anatomically,
blood is considered to be …….…………... tissue for both its origin in the bones and its function.

Blood accounts for seven per cent of the human body …….…………..., with an average density of
approximately 1060 kg/m³, very close to pure water’s density of 1000 kg/m^3. The average adult has
a blood volume of about …….…………... litres.

Red blood cells are produced in the red …….…………...; this process is referred to as  …………………. Some
bones that contain blood producing marrow may cease to fulfil this function over time. During
childhood, almost every human bone produces red blood cells; in adults, red blood cell production
tends to limit itself to the vertebrae, breastbone, rib cage, pelvis and parts of upper and lower
extremities.

Human blood is divided into four groups: A, B, AB, 0, according to the type of …….…………... on the
surface of red blood cells. Blood …………….….. is a process of voluntarily giving blood for storage in
a blood …….…………..., generally for subsequent use in blood transfusions.

    erythrocytes   plasma    four     erythropoiesis     concave      leukocytes    bank    up
        vessels    haemoglobin    connective     donation       blood serum         tissue
       platelets      bone marrow      against     granulocytes     agranulocytes   antigens
                   coagulation      weight             proteins          volume


                                       The Lymphatic System

1.      What are the individual parts of the lymphatic system?

2.      Which organ is the filter for lymph?

3.      Which part of the body serves as the storehouse for the cellular debris collected by the
lymphatic system?

4.      Which organ protects the body from infections at the entrance to the digestive and
respiratory tracts?