Tag: transport in animals

Questions Related to transport in animals

Purkinje fibres mainly helps in contraction of

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

  1. Right auricle

  2. Left ventricle

  3. Ventricles

  4. Aorta

Show answer
Correct Option: C
Explanation:

The Purkinje fibers are specialised conducting fibres present in the inner ventricular walls of the heart. They help in the contraction of the ventricles and thus maintain the rhythmicity of the heart. 

'Bundle of His' is group of

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

  1. Nerve fibres

  2. Ganglia

  3. Connective tissue

  4. Muscle fibres

Show answer
Correct Option: D
Explanation:

The bundle of His is a group of muscle cells that transmits the electrical impulses from AV node to the ventricle wall via Purkinje fibres. 

Which of the following set is correct?

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

  1. Sebum - Analgesic

  2. Vitamin - Nicotine

  3. Corpus callosum - Graffian follicle

  4. Bundle of His - Purkinje fibre

Show answer
Correct Option: D
Explanation:

The bundle of His is the upper end of the electrical path,which through the Purkinje fibres allows the electrical signal to activate the ventricles and thus to pump the blood.

So, the correct answer is 'Bundle of His - Purkinje fibre'.

Vagus nerve slows down heart beat due to secretion of

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

  1. Adrenaline

  2. Acetylcholine

  3. Norepinephrine

  4. Dopamine.

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Correct Option: B

In human foetus, the heart begins to beat at developmental age of

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

  1. $4$ week

  2. $3$ week

  3. $6$ week

  4. $8$ week

Show answer
Correct Option: A
Explanation:

During $3$ to $4$ weeks of gestation, the heart usually starts beating in human foetus.

So, option A is the correct answer.

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? 

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

  1. One

  2. Two

  3. Four

  4. Three

Show answer
Correct Option: A
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'.

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

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

  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

Show answer
Correct Option: C
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.'

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.

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

  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.

Show answer
Correct Option: D
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.'

The atrio-ventricular node is situated

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

  1. Near the bicuspid valve

  2. In between the atrium

  3. At the base of inter-auricular septum

  4. In the interventricular septum

Show answer
Correct Option: C
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.

In which the following has the ability to generate action potentials without any external stimuli? 

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

  1. Sino-atrial node(SAN)

  2. Atrio-ventricular node (AVN)

  3. Purkinje fibers

  4. All of the above

Show answer
Correct Option: A
Explanation:

Sino-atrial node(SAN)  is known as a pacemaker and has the ability to generate action potentials without any external stimuli.