heart? 8. Mention the function of valves present in the heart 9. Why do mature RBCs do not have nucleus in them? 10. Why do arteries have thick walls? C. Long answer questions : 1. Explain with the help of a flow chart the systemic and pulmonary circulation in heart. 2. Mention any four functions of Lymph. 3. Write any six differences between Artery and Vein. 4. Describe the working of human heart. Candid N
Answers
Explanation:
The valves prevent the backward flow of blood. These valves are actual flaps that are located on each end of the two ventricles (lower chambers of the heart). They act as one-way inlets of blood on one side of a ventricle and one-way outlets of blood on the other side of a ventricle.
Answer:
8. valve function of the heart is to produce blood and maintain circulation in the body.
9. Mature RBC lack nucleus to increase the haemoglobin which increases the oxygen transport as well as maintaining the bi-concave shape that help in easy diffusion in blood vessels.
10. Thick walls of arteries help them to resist the pressure of flow of blood in them.
C) 1. refer attachment!
2. Functions of lymph are :-
- It keeps the body cells moist.
- It transports oxygen, hormones and nutrients to different parts of the body and removes metabolic waste from the cells.
- It transports antibodies and lymphocytes to the blood.
- Maintaining the composition of tissue fluid and the volume of blood.
3.
- Arteries carry oxygenated blood rich in nutrients Veins carry impure blood rich in waste material of the body.
- Arteries have thicker wall (more tissue) The veins have thin walls (less tissue)
- Arterial walls have more strength, when cut remain open Veins are comparatively delicate. When cut they collapse
- Blood flows by pulsatile manner corresponding to heart beat. No pulse, blood flows uniforms
- Oxygen levels is quite high in arterial blood Oxygen level is low comparatively
- CO2 level is low in arterial blood CO2 level is high in venous blood.
4. The heart functions as a pump & it keeps the blood circulating in the whole body. The rhythmic contraction of the heart is called a heartbeat.
