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 cardiac cycle simple nutrients into cells the circulatory system biology

In the heart of frog, which of the following is considered as the pacemaker?

  1. Pylangium

  2. Synangium

  3. Truncus

  4. Sinus venosus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In amphibians, such as the frog, the pacemaker is the sinus venosus, an enlarged region between the vena cava and the right atrium. The venae cavae do not open directly into the auricles but into another chamber, the sinus venosus, which drains into the right auricle. 

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

An artificial pacemaker is implanted subcutaneously and connected to the heart in patients

  1. Having 90% blockage of the three main coronary arteries

  2. Having a very high blood pressure

  3. With irregularity in the heart rhythm

  4. Suffering from arteriosclerosis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
An artificial pacemaker is implanted subcutaneously and connected to the heart in patients with irregularity in the heart rhythm. It is implanted in the region of SA node which regulates the heartbeat. Sinoatrial node is known as the pacemaker of the heart. It helps in the generation and conduction of heartbeat. It is located in the walls of the right atria just below the opening of superior vena cava. The sympathetic nerves release the neurotransmitters and activate the SA node and generate electric impulse which is conducted as heartbeat throughout the heart. 
So, the correct answer is option C.
Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

The cardiac pacemaker in a patient fails to function normally. The doctors find that an artificial pacemaker is to be grafted in him. It is likely that it will be grafted at the site of

  1. Sinoatrial node

  2. Atrioventricular node

  3. Atrioventricular bundle

  4. Purkinje system
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sinoatrial node is known as pacemaker of the heart. It helps in the generation and conduction of heart beat. It is located in the walls of the right atria just below the opening of superior venacva. The sympathetic nerves release the neurotransmitters and activates the SA node and generates electric impulse which is conducted as heart beat through out the heart. 

When the cardiac pacemaker in a patient fails to function normally a artificial pacemaker is implanted at the site of SA node. It is a medical device which uses electrical impulse, generated by electrodes to contract the heart muscles, and regulate the heart beat.
So, the correct answer is option A.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

Function of SA node is to ensure

  1. Muscular pain

  2. Contraction of lungs

  3. Heart beat

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

The entire heart is made of cardiac muscles. A specialized cardiac musculature called the nodal tissue is also distributed in the heart i.e sino-atrial node (SAN- A patch of this tissue is present in the right upper corner of the right atrium ). The nodal musculature has the ability to generate action potentials without any external stimuli, i.e., it is autoexcitable. Hence function of the SA node is to ensure heartbeat.

So, the correct answer is 'Heartbeat'.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

Pacemaker is situated in heart

  1. In the wall of right atrium

  2. On interauricular septum

  3. On interventricular septum

  4. In the wall of left atrium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Pace maker is Sinoatrial or SA node situated in the upper corner of wall of right atrium in heart. It initiates and maintains the rhythmic contraction of heart. Excitation waves begin in SA node due to which atria contract and the oxygenated and deoxygenated blood is forced into respective ventricles through atrioventricular valves. It acts as stimulus for the next wave of excitation and thus, maintains the frequency of heart beat.
So, the correct answer is 'In the wall of right atrium'.
Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

State whether the following statements are true or false.
A  pacemaker is a tiny computerised electrical device that is implanted in -a patients body to regulate the brain activity.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pacemaker is a tiny battery run instrument placed near to the heart of a patient for generation impulses similar to the SA node for the rhythmic functioning of the heart

So, the correct answer is 'False'

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

Which of the following is the correct pathway for propagation of cardiac impulse?

  1. SA node $\rightarrow$ AV node $\rightarrow$ Bundle of His $\rightarrow$ Purkinje fibres
  2. AV node $\rightarrow$ Bundle of His $\rightarrow$ SA node $\rightarrow$ Purkinje fibres
  3. SA node $\rightarrow$ Purkinje fibres $\rightarrow$ AV node $\rightarrow$ Bundle of His
  4. Purkinje fibres $\rightarrow$ AV node $\rightarrow$ SA node $\rightarrow$ Bundle of His.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cardiac impulse generates from SA node then it reaches to AV node, then to bundle of HIS and finally to Purkinje fibers, this is how the cardiac impulse is generated.

So, the correct option is 'SA node 
→→ AV node →→ Bundle of His →→ Purkinje fibers'.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

What happens when the pacemaker becomes nonfunctional?

  1. Only auricles contract rhythmically

  2. Only ventricles contract rhythmically

  3. Cardiac muscles do not undergo co-ordinated rhythmic movements

  4. Auricles and ventricles contract rhythmically
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If the SA node fails, the heart loses its coordinated rhythmic contraction because the electrical signal is not initiated correctly, leading to arrhythmia.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

An artificial pacemaker is implanted subcutaneously and connected to the heart in patients

  1. Having 90% blockage of the three main coronary arteries

  2. Having a very high blood pressure

  3. With irregularity in the heart rhythm

  4. Suffering from arteriosclerosis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pacemaker serves to produce rhythmic impulses for the heart beat. The sinoatrial node (SA) node serves as a pacemaker and is a small mass of specialized cardiac muscle. It is present in the posterior wall of the right atrium near the opening of superior vena cava. 

When the natural pacemaker is defective, the heartbeat may be too fast, too slow or irregular. Artificial pacemakers are electronic devices that stimulate the heart with electrical impulses to maintain or restore a normal rhythm in people with slow heart rhythms. An artificial pacemaker provides an electrical impulse (discharge) that can stimulate the heart, thus restoring or maintaining a regular heartbeat. 
So, the correct answer is option C.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

The 'cardiac pacemaker' in a patient fails to function normally. The doctors find that an 'artificial pacemaker' is to be grafted in him. It is likely that it will be grafted at the site 

  1. Purkinje fibres

  2. Under the clavicle

  3. Atrioventricular node

  4. Bundle of His
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Sinoatrial (SA) node is the natural pacemaker of the heart. It generates the nerve impulses needed for heart contraction. When the SA node stops functioning, an artificial pacemaker should be implanted for proper conduction of impulse.
The artificial pacemaker is implanted inside the skin under the clavicle. In this, a vein is incised with the insertion of electrode lead through the valve of heart.
So, the correct answer is option B.
Multiple choice evs circulation of blood circulatory system and organs basics of blood and heart transportation in living organisms

The portion of heart which doesn't receive proper blood supply becomes

  1. Strong

  2. Dead

  3. Weak

  4. Diseased
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
When the heart tissue does not receive an adequate blood supply, it cannot function. The heart muscle weakened due to lack of food and oxygen. Improper supply of blood to heart usually causes pain and infected portion of muscles may die.
So the correct answer is 'Weak'.
Multiple choice evs circulation of blood circulatory system and organs basics of blood and heart transportation in living organisms

Read the following statements carefully.
$(1)$ In fishes the heart pumps out deoxygenated blood which is oxygenated by the gills and supplied to the body parts from where deoxygenated blood is returned to the heart
$(2)$ The openings of the right and the left ventricles into the pulmonary artery and the aorta respectively are provided with the mitral valves.
$(3)$ The nodal musculature has the ability to generate action potential without any external stimuli, i.e., it is auto-excitable
$(4)$ The T-wave of ECG represents depolarization of the ventricles
Which of the given two statements are correct?

  1. $1$ and $3$
  2. $2$ & $4$
  3. $1$ and $2$
  4. $3$ & $4$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The correction in statements (2) and (4) are:

  • In vertebrates, the mitral valves are present between the left atrium and the left ventricle.
  • The T wave of ECG represents repolarization of the ventricles, not depolarization.
So, the correct answer is '1 and 3'.

Multiple choice evs transportation in living organisms circulatory system and organs basics of blood and heart circulatory system

When the muscles of the heart relax

  1. Blood flows from lungs into the left auricle

  2. Blood is pumped into the right auricle from all over the body

  3. Both a and b

  4. Blood flows from the left ventricle to the rest of the body
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When the muscles of the heart relax, the right atrium receives deoxygenated blood from all parts of the body through superior, inferior vena cava and coronary sinus. The left atrium receives oxygenated blood from the lungs through two pairs of pulmonary veins. Thus option C is the correct answer. 

Multiple choice evs transportation in living organisms circulatory system and organs basics of blood and heart circulatory system

The separation of the atria and ventricle helps to 

  1. Prevent mixing of the blood

  2. Pump blood only to lower parts of the body

  3. Pump blood only to upper parts of the body

  4. Both A and C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In the humans, the heart is a four-chambered muscular organ situated in the thoracic cavity in between the lungs. The upper two relatively small chambers are called atria and two larger lower chambers called ventricles. A thin, muscular wall called the interatrial septum separates the right and the left atria. whereas a thick-walled, the inter-ventricular septum, separates the left and the right ventricles. The right side of the heart has oxygenated blood and the left side has deoxygenated blood. Hence, the separation of the atria and ventricle helps to prevent mixing of the oxygenated and deoxygenated blood.
So, the correct answer is 'Prevent mixing of the blood'.