Biology
The figures given below show diagrammatic cross-sections of three kinds of blood vessels.
(a) Identify the blood vessels A, B and C.
(b) Name the parts labeled 1-4.
(c) Mention two structural differences between A and B.
(d) Name the kinds of blood that flow through A and through B respectively.
(e) In which one of the vessels referred to in (a) above does the exchange of gases actually take place?
Answer
(a) The blood vessels A, B and C are:
- A → Artery
- B → Vein
- C → Capillary
(b) The parts labeled 1-4 are:
- 1 → External layer made of connective tissue
- 2 → Lumen
- 3 → Middle layer of smooth muscles and elastic fibres
- 4 → Endothelium
(c) Two structural differences between Artery and Vein are:
| Artery | Vein |
|---|---|
| Have thick and more muscular walls. | Have thin and less muscular walls. |
| Have narrower lumen. | Have wider lumen. |
(d) The kinds of blood that flow through A and through B are:
- A (Artery) → Oxygenated blood
- B (Vein) → Deoxygenated blood
(e) At the capillary level the actual exchange of gases takes place.
Related Questions
Given below is a highly schematic diagram of the human blood circulatory system.
(a) Which part (state the number) represents the heart? Give reason in support of your answer.
(b) Which numbers represent the following respectively?
Aorta
Hepatic portal vein
Pulmonary artery
Superior vena cava
Renal vein
Stomach
Given below is a diagram of a smear of human blood. Study the same and answer the questions that follow:
(a) Name the parts 1, 2, 3 and 4 indicated by guidelines.
(b) Mention two structural differences between the parts labelled 1 and 2.
(c) What is the main function of the parts labelled 1, 2 and 3 respectively?
(d) What is the life span of the part labeled "1"?
(e) Name a soluble protein found in "4" which helps in clotting of blood.
Study the following diagram carefully and then answer the questions that follow:
(a) Name the cell labelled 1.
(b) Identify the phenomenon occurring in A.
(c) Mention two structural differences between 1 and 2.
(d) Name the process occurring in B and C and state the importance of this process in the human body.
The diagram given below represents the human heart in one phase of its activity. Study the same and then answer the questions that follow:
(a) Name the phase.
(b) Which part of the heart is contracting in this phase? Give a reason to support your answer.
(c) Name the parts numbered 1 to 6.
(d) What type of blood flows through the parts marked '1' and '2' respectively?
(e) How many valves are closed in this phase?