Tag: transport in animals

Questions Related to transport in animals

What happens when the pacemaker becomes non-functional?

biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Only auricles contract rhythmically

  2. Only ventricles contract rhythmically

  3. Cardiac muscles do not undergo coordinated rhythmic movements

  4. Cardiac muscles contract in coordinated manner rhythmically

  5. Auricles and ventricles contract rhythmically.

Show answer
Correct Option: C
Explanation:

The natural (SA node) or artificial pacemaker has a function to send electrical impulses from atrium for contraction and pumping action into the ventricles. The impulses get transferred in the following route :

SA node(pacemaker) $\rightarrow$ Interatrial cardiac fibre $\rightarrow$ AV node(pacesetter) $\rightarrow$ Bundle of his $\rightarrow$ Bundle branch $\rightarrow$Purkinje fibres.
Thus, the rhythmic contraction of the heart is made by SA node.
So, if the pacemaker becomes non-functional then, cardiac muscles do not undergo coordinated rhythmic movement.

'Bundle of His' is a part of which one of the following organs in humans?

biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

  1. Brain

  2. Heart

  3. Kidney

  4. Pancrease

Show answer
Correct Option: B
Explanation:

Bundle of His is a part of heart, It is collection of heart muscles cells and specialized for electrical conduction .So option (B) Heart is correct answer.