Question
The diagram shows part of the human circulatory system
What are the numbered blood vessels?
▶️Answer/Explanation
Ans: C
The correct answer is C, because :
Arteries carries blood from heart to tissues and veins carries blood from tissues to heart.
• Vein that carries blood from all tissues to heart is the vena cava.
• Vein that carries blood from lungs to heart is called pulmonary vein.
• Artery that carries blood from the heart to kidney is called renal vein.
Question
Which diagram shows the human double circulatory system?
Answer/Explanation
Ans: D
The correct answer is D, because :
Double circulation means, the blood passes through the heart twice during one cycle.
Question
What ensures one-way flow of blood in the circulatory system?
A atria
B septum
C valves
D ventricles
▶️Answer/Explanation
Ans C
The correct answer is C, because :
Valves are the components of vein which regulates the single directional blood flow and against gravity in case of limbs.
Whereas,
• Atria is the heart chamber
• Septum is the separation between chambers of heart
• Ventricles are the chambers of heart
Question
The diagrams show sections through three blood vessels, which are not drawn to the same scale.
Some red blood cells are shown in vessel 3. In which order will red blood cells flow through these vessels when travelling from the right ventricle
to the left atrium of the heart?
A 1 → 2 → 3
B 1 → 3 → 2
C 2 → 3 → 1
D 3 → 1 → 2
▶️Answer/Explanation
Ans B
The correct answer is B, because :
From right ventricle of the heart, blood flows from ventricle to lung through pulmonary artery (it will have a narrow lumen), and from lungs it comes to left atrium through pulmonary vein (more wide lumen) and inbetween it crosses capillaries for exchange of oxygen and nutrients at alveoli.
As per this understanding, the first one should be narrow lumen ( diagram 1 ), then normal flow of blood at capillaries (diagram 3 ) and atlast wide lumen ( diagram 2 )
So the answer will be 1,3,2.