Question

P in the heart have thicker muscular walls than Q do. Also, R ensures that blood does not flow backwards when the atria or ventricles contract.
P is ________

Q is ______

and R is_________

• A. P- ventricles Q- atria R- valves
• B. P: Atria, Q: Ventricles and R: Valves
• C. P: Ventricles, Q: Blood vessels and R: Atria
• D. P: Blood Vessels, Q: Atria and R: Valves

Answer 1

The correct option is A

P- ventricles

Q- atria

R- valves

The heart consists of four chambers, right and left atria above right and left ventricles.The right atrium links to the right ventricle by the tricuspid valve while the left atrium links to the left ventricle by the bicuspid valve .These valves prevents backflow of the blood into atrium when the ventricle contracts. Ventricles have thicker muscular walls than atria. When each atrium contracts, it only needs to propel the blood a short distance into each ventricle while the ventricles need a more powerful contraction to propel blood to the systemic circulation.

Therefore P is ventricles
Q is atria
and R is valves