Tag: cardiac cycle

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Questions Related to cardiac cycle

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

Where is the pacemaker situated?

  1. In left auricle near opening of pulmonary vein

  2. In right auricle near eustachian valve

  3. On inter-auricular septum

  4. On inter-ventricular septum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sino-atrial node is the natural pacemaker of the heart. These are a group of small, flattened and ellipsoid strip cardiac muscle fiber situated in the upper lateral wall of the right atrium near the Eustachian valve (valve of the inferior vena cava).

So, the correct answer is option B.

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

Pacemaker influences

  1. Contraction of heart muscles

  2. Flow of blood in heart

  3. Rate of heart beat

  4. Formation of nerve impulse
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A specialised cardiac musculature, called as the nodal tissue is distributed in the heart. A patch of this tissue is present in the right upper corner of the right atrium, called as the sino-atrial node (SAN). 

The nodal musculature has the ability to generate action potentials without any external stimuli, i.e., it is auto excitable. The 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 heart.

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

The heartbeat is regulated by a small node of cardiac muscles called

  1. Pericardium

  2. Ventricle

  3. Tricuspid valve

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

A small node of specialized tissue is located int he upper right corner of right ventricle called as SA node. It is known as natural pacemaker of heart as it is responsible for initiation and regulation of heart beat. 

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

In which of the following pairs, the two items mean one and the same thing?

  1. Malleus - Anvil

  2. SA node - Pacemaker

  3. Leucocytes - Lymphocytes

  4. Haemophilia - Lung cancer
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Malleus is hammer like bone of the middle ear. 

SA node is called as pacemaker of the heart that sets the beat. 
Leucocytes are WBCs and lymphocytes are B and T cells. 
Hemophilia is a blood disorder.
Therefore, the correct answer is option B.

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

Mark the correct match.

  1. Malleus - Anvil

  2. SA node - Pacemaker

  3. Leucocytes - Lymphocytes

  4. Haemophilia - Blood cancer
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A. Malleus is known as hammer bone and is the largest ear ossicles.
B. SA node is known as pacemaker. It initiates and maintains the rhythmic contraction of heart.
C. Leucocytes are white blood cells. Lymphocytes are agranular leucocytes i.e. white blood cells which do not contain granules. They are a type of white blood cells.
D. Haemophilia is a genetic disorder in which blood doesn't clot due to deficiency of coagulation factor. 
Hence, option B is a correct match.
So, the correct answer is 'SA node - Pacemaker'.
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'.