Question

Answer the follwing questions in your own words.
a.Explain the functional correlation of circulatory system with respiratory, digestive and excretory system.
b.Explain the structure and function of human blood.
c.Explain the importance and need of blood donation.

Answer 1

a. The functional corelation between circulatory system with respiratory, digestive and excretory system is as follows:

We already know that during respiration exchange of gases occurs in the lungs. The respiratory system causes the diffusion of oxygen into the blood and the diffusion of CO₂ out of the blood. The oxygen is then transported to cells of the body via the circulatory system.
The digestive system is responsible for producing nutrients by breaking complex molecules into simpler ones. The circulatory system then tranports these nutrients to different cells and tissues.
The excretory system is responsible for the elmination of waste products from the body. These waste products are transported by blood to the excretory system.


b. Blood is a fluid connective tissue that flows in blood vessels. It is composed of two components- plasma and blood cells.

Plasma is a yellowish colour fluid, made up of water (~90%) and some dissolved nutrients, proteins, hormones and waste products.

Blood consists of three types of blood cells. These are

i. Red Blood Cells: They contain a red pigment called haemoglobin, which transports oxygen to all body cells.

ii. White Blood Cells: They fight against germs that enter the body. Thus, they protect the body from diseases.

iii. Platelets: When we get injured, bleeding stops after some time. This happens because of the activity of platelets, which help in the clotting of blood.

Functions of blood:

• It transports nutrients and oxygen to the different parts of the body.

• It also carries waste materials (from the different parts of the body) to be removed by the excretory organs.

• Chemical messengers like hormones are transported by the blood.

• Protects the body from disease carrying germs.

• Helps to maintain a constant body temperature.

c. Blood donation is one of the biggest donations of an inidivisual towards their society. Blood loss can occur under circumstances of accidents, during surgeries or in case of diseases which require blood transfusion. Adequate amount of available blood can save many lives. It does not harm or effect the body of the donor and the amount of blood which is donated is recovered within 24 hrs.
This donated blood can be stored and used as and when the requirement arises.