Physical and chemical properties of the blood. Physiology of red blood cells educational manual

3. 
Nutritional.
End products of digestion are absorbed from the gastrointestinal tract and 
transported by the blood to the liver for further processing and then to the tissues 
who need them. 
4. 
Role of blood in various homeostatic processes.
The term 'homeostasis' has been explained earlier (sec.1, chap.3). Briefly 
speaking, this is a mechanism, by which the various parameters of our body, like 

---

the internal temperature, pH, the concentrations of various substances (for 
example, glucose, sodium, potassium etc.) in our body fluids, remain within a 
narrow range. 
(a) 
Body temperature and blood. The volume of blood is large (around 5 
liters in an adult man) and the ‘specific heat’ of blood is high. Therefore, a good 
deal amount of heat (calories) can be absorbed or lost by the blood without a great 
rise or fall in the temperature. It is to be noted that the enzymes in our body operate 
satisfactorily only in a narrow range of temperature. So either an abnormal rise or 
an abnormal fall of temperature, damages the enzymes and ultimately stops all 
biological activities. In this regard blood acts as a part of our body water content. 
Moreover, blood has a high conductivity. If an organ becomes hot (eg. liver, 
due to vigorous metabolic activities) the heat from the organ is taken out by blood 
and distributed throughout the body. 
(b) 
pH and blood. The enzymes of our body act only within a narrow 
range of pH. Again, large amount of acids are produced daily, by our body, as a 
result of metabolism. The blood contains various buffers, which prevent the rise of 
H+ concentration. Circulation of blood also contributes to the removal of the H
+
. 
5. Role of blood in various defense mechanism.
The white blood cells of blood act against invading bacteria and virus. The 
lymphocytes are intimately connected with the immunity of the body. The plasma 
carries antibodies. These are some examples to show the importance of blood in 
connection with the defense.