Question

The diagrams given are cross sections of blood vessels
(i) identify the blood vessels A, B and C.
(ii) name the parts labelled .
(iii) name the type of blood that flows through A.
(iv) mention one structural difference between A and B.
(v) in which of the above vessels does exchange of gases actually take place?
                   

Answer 1

Hint: The inside lining of arteries and veins is made up of squamous epithelium, a middle layer of smooth muscles and elastic fibres known as tunica intima, and an external layer of collagen fibres known as tunica externa.
Blood passages that carry blood away from the heart are called arteries, whereas blood vessels that return blood to the heart are called veins. Capillaries are small blood arteries with a thin wall that allow chemicals to diffuse across the body's tissues and organs.

Complete answer:
Part (i)-
A: artery B: vein C: capillary
Part (ii)-
1- connective tissue layer
2- lumen
3- muscular layer
Part (iii)- oxygenated blood
Part (iv)- The wall of A has a thick muscular and elastic layer with a small lumen, whereas the wall of B has a thin muscular layer with a less elastic wall and a broad lumen.
Part (v)- The exchange of gases such as oxygen and carbon dioxide takes place in a capillary channel.

Additional information:
The three main types of blood vessels are: -Arteries transport blood from the heart to the body's many organs via arterioles. As a result, the capillary network is formed, which now carries chemical exchange between tissues and blood.
Finally, capillaries joined together to form venules. As a result, bigger veins are formed. Veins are responsible for returning blood to the heart, while anastomoses are the connections between blood and the heart.

Note:
A network of blood vessels known as vasa vasorum supplies the cells of the walls of arteries and veins. Vasa vasorum is Latin for "vessels of the vessel."
The systemic circulation and the pulmonary circulation are two separate circuits that circulate blood within the body.
In pulmonary circulation, deoxygenated blood is pushed to the lungs to be oxygenated, and oxygenated blood is pumped to the body's tissues in systemic circulation.