Q.5 Give scientific reason.
1. Closed circulation is more efficient than
open circulation.
2. Human heart is called as myogenic and
autorhythmic.
3. Person who has undergone heart
transplant needs lifetime supply of
immunosupressants.
4. Arteries are thicker than veins.
5. Left ventricle is thick than all other
chambers of heart.
Answers
Answer:
1. The closed circulatory system is more efficient than the open system because in closed system the blood flows inside arteries or veins all the time which stops the mixing of blood with other bodily fluids and helps the transport of the blood around the body.
2. The heart shows autorhythmicity because the impulse for its rhythmic movement develops inside the heart. Such heart is called myogenic. Some of the cardiac muscle fibres become autorhythmic (self-excitable) and start generating impulses during development.
3. After transplantation, there is a risk of graft rejection as the body may recognize the transplanted organ/tissue as foreign and may trigger an immune response thereby damaging the transplanted organ. Therefore, the heart recipient has to rely upon lifetime supply of immunosuppressants.
4. Veins are generally larger in diameter, carry more blood volume and have thinner walls in proportion to their lumen. Arteries are smaller, have thicker walls in proportion to their lumen and carry blood under higher pressure than veins. Arteries and veins often travel in pairs using the same connective tissue pathways.
5. Answer is in the above picture.
