Advertisements
Advertisements
Question
What are the heart sounds? When and how are these sounds produced?
Advertisements
Solution
-
Rhythmic contraction and expansion of heart is called heart beat. The contraction of the heart is called systole and the relaxation of the heart is called diastole. The heart normally beats 70-72 times per minute in a human adult. During each cardiac cycle two sounds are produced that can be heard through a stethoscope.
-
The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves whereas Second heart sound (dub) is associated with the closure of the semilunar valves. These sounds are of clinical diagnostic significance. An increased heart rate is called tachycardia and decreased heart rate is called bradycardia.
RELATED QUESTIONS
Write the differences between open and closed system of circulation
Describe the evolutionary change in the pattern of heart among the vertebrates.
Sino-atrial node is called the pacemaker of our heart. Why?
What is the significance of atrio-ventricular node and atrio-ventricular bundle in the functioning of heart?
Conversion of ammonia into uric acid occurs through --------------
At any given time there is more blood in the venous system than that of the arterial system. Which of the following features of the veins allows this?
Select the correct biological term.
Destroyed in the liver and spleen after circulating in the blood for four months.
Select the correct biological term.
The substances which gives red cells their colour.
Which among the followings is correct during each cardiac cycle?
Read the following statements and choose the correct option
Statement 1: Atria receive 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.
Write the features that distinguish between the two.
Sino-atrial node and Atrio-ventricular node
Answer the following:
Which part of heart is responsible for initating and maintaining its rhythmic activity?
Answer the following:
What is specific in the heart of crocodiles among reptilians?
In the diagrammatic presentation of heart given below, mark and label, SAN, AVN, AV bundles, bundle of His and Purkinje fibres.
Cardiac activities of the heart are regulated by ______.
- Nodal tissue
- A special neural centre in the medulla oblongata
- Adrenal medullary hormones
- Adrenal cortical hormones
Choose the correct answer from the options given below:
Following are the stages of pathway for conduction of an action potential through the heart:
- AV bundle
- Purkinje fibres
- AV node
- Bundle branches
- SA node
Choose the correct sequence of pathway from the options given below:
