Biology

Cardiovascular and Nervous System

981 Questions

Review the human cardiovascular system through these competitive exam practice questions. Key areas include heart valves, cardiac impulse pathways, and blood pressure regulation. A solid grasp of these fundamentals is crucial for science sections.

Heart anatomy and valvesCardiac impulse conductionBlood pressure mechanicsHeartbeat regulation

Cardiovascular and Nervous System Questions

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

Heart beat in vertebrates is

  1. Neurogenic

  2. Myogenic

  3. Both of the above

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Myogenic contraction refers to a contraction initiated by the myocyte cell itself.

In vertebrates, normal activities of the heart are regulated intrinsically, i.e., auto regulated by specialised muscles (nodal tissue). Hence, the heart is called as myogenic. 
Heart is neurogenic in arthropods.

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

The heart of a healthy man beats normally .................. per minute

  1. 50 - 60 times

  2. 70 - 80 times

  3. 90 - 100 times

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The sinoatrial node (SAN) can generate the maximum number of action potentials, i.e., 70 - 75 beats/min, and is responsible for initiating and maintaining the rhythmic contractile activity of the heart. Therefore, it is called as the pacemaker of the heart.

Multiple choice biology transport in mammals cardiac cycle heart, blood vessels and cardiac cycle human heart

Choose the correct answer from the alternatives given.
The typical lub-dub sounds heard in the heart beat of a healthy person are due to:

  1. closing of the semilunar valves

  2. closing of the tricuspid and bicuspid valves

  3. closing of the tricuspid and bicuspid valves followed by the closing of the semilunar valves

  4. blood flow through the aorta
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Heart sounds are noises generated by the closing and opening of the heart valves. In a healthy individual, there are two normal heart sounds called lub and dub. Lub is the first heart sound. It is associated with the closure of the tricuspid and bicuspid valves at the beginning of systole. The second heart sound dub is associated with the closure of the semilunar valves at the beginning of diastole.

So, the correct option is 'closing of the tricuspid and bicuspid valves followed by the closing of the semilunar valves'.

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

Go through the statements
Statement (I): The AV node and the bundle of His constitute the only electrical link between the atria and the ventricles.
Statement (II): The Bundle of His is a bundle of electrical nodes which allow the ventricles to contract.
Statement (III): The bundle of His is a group of fibres that carry electrical impulses through the centre of the heart
Statement (IV) : The bundle of His is located in the proximal intraventricular septum
How many of the above statements are correct? 

  1. One

  2. Two

  3. Four

  4. Three
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The AV node is located at the inferior end of the inter-atrial septum and the Bundle of His help in transmission of electrical impulses from the AV node to the ventricles. So, they constitute the electrical link between the atria and the ventricles.
  • The Purkinje fibres carry the electrical impulses from the left and the right bundle of his (in the ventricles) to the contractile cells of the myocardium and cause contraction of the ventricles.
  • The bundle of his is a bundle of cardiac muscle fibres that carry the electrical impulses from the AV node located at the inferior end of the inter-atrial septum (near the bottom of the right atrium) into the right and the left ventricles. They, therefore, do not carry impulses through the centre and are not located only at the proximal end of the interventricular septum.
So, the correct option is 'One'.
Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

The cardiac impulse is initiated and conducted further upto ventricle. The correct sequence of conduction of impulse is 

  1. SA Node, AV node, Purkinje fibre, AV Bundle

  2. SA Node, Purkinje fibre, AV Node, AV Bundle

  3. SA Node, AV node, AV Bundle, Purkinjee fibre

  4. SA Node, Punkinje fibre, AV Bundle, AV Node
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The nerve impulses produced by the SA node travel to the AV node and cause the initiation of the articular depolarization. From here, the impulse travels to the AV bundle and then to the Purkinje fibres.
Thus, the correct answer is 'SA Node, AV node, AV Bundle, Purkinje fibre.'
Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

Read the following statements and choose the correct option.
Statement 1: Atrial receives blood from all parts of the body which subsequently flows to ventricles.
Statement 2: Action potential generated at sino-atrial node passes from atria to ventricles.

  1. Action mentioned in Statement 1 is dependent on action mentioned in Statement 2.

  2. Action mentioned in Statement 2 is dependent on action mentioned in Statement 1.

  3. Actions mentioned in Statements 1 and 2 are independent of each other.

  4. Actions mentioned in Statements 1 and 2 are synchronous.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Atria receive blood from all parts of the body which subsequently flows to the ventricles. Action potential generated at sinoatrial node passes from the atria to the ventricles. Both these events take place at the same time.

Thus, the correct answer is 'Actions mentioned in Statements 1 and 2 are synchronous.'

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

The atrio-ventricular node is situated

  1. Near the bicuspid valve

  2. In between the atrium

  3. At the base of inter-auricular septum

  4. In the interventricular septum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The heart beat originates at SA node and passes to the AV node which finally conducts it to the bundle of His. The AV node is placed between the atria and the ventricles of the heart, specifically in the posteroinferior region of the interatrial septum near the opening of the coronary sinus, which conducts the normal electrical impulse from the atria to the ventricles.

So, the correct answer is option C.

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

What happens when the pacemaker becomes non-functional?

  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.
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice biology respiration in organism human respiration the mechanism of breathing breathing and its movements

During running or cycling ,Which of the following organs have to increase their activity

  1. Heart

  2. Lungs

  3. Both (1) and (2)

  4. Kidneys
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

During any physical exercise such as running or cycling the two vital organs of our body heart and lungs come into action since lung try to bring oxygen into the body to provide energy and side by side removing carbon dioxide formed by strenuous physical activity. While the heart pumps oxygen-rich blood to skeletal muscle undergoing physical exercise to meet their metabolic requirements.

Thus, the correct answer is  'Both (1)-Heart and (2)-Lungs'.