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In humans, blood passes from the post caval to the diastolic right atrium of heart due to
Diastolic right atrium has less pressure and post caval has high pressure, thus blood moves from post caval to right atrium.
Which one of the following is a matching pair?
During ventricular systole, the contraction of ventricular muscles causes the closure of bicuspid and tricuspid valves (AV valves), producing a low pitched 'lubb' sound. At the end of ventricular systole, semilunar valves close, producing the second heart sound, the 'dup'. Pulsation of the radial artery is due to rhythmic contraction and relaxation in the aorta. Initiation of the heart beat occurs in the SA node.
During ventricular systole:
Due to contraction of the ventricles (ventricular systole), the pressure inside the ventricles rises, that force open the semilunar valves of aorta and pulmonary artery so that the blood enters into these vessels. Oxygenated blood is pumped into the aorta from the left ventricle while deoxygenated blood is pumped into the pulmonary artery from the right ventricle.
If due to some injury, the chordae tendineae of the tricuspid valve of the human heart is partially non-functional, what will be the immediate effect?
Chordae tendineae are cords that prevent the valve from collapsing back into the right atrium during powerful right ventricular contraction. When the right ventricle contracts forcing blood into the pulmonary artery, the tricuspid valve closes the aperture to the right atrium thereby preventing any backflow of blood. Thus, if chordae tendineare of tricuspid valve becomes partially non-functional, then the flow of blood into the pulmonary artery will be reduced.
Which one of the following statements is correct regarding blood pressure?
Normal blood pressure is 120/80 mm Hg. Blood pressure of 190/110 mm Hg is regarded as high blood pressure. It leads to heart diseases and also affects vital organs like brain and kidney.
Consider the following statements each with one or two blanks.
(i) Left auriculoventricular aperture is guarded by (1) valve while right auriculoventricular aperture is guarded by (2) valve.
(ii) In man left auricle receives (3) blood by (4) pulmonary veins.
(iii) (5) ions play a significant role in clotting.
Which one of the following options, gives the correct fill-ups for the respective blank numbers from (1) to (5) in the statements?
Which of the following statement(s) regarding the cardiac system is/are correct?
(i) Human heart is an ectodermal derivative.
(ii) Mitral valve guards the opening between the right atrium and left ventricle.
(iii) SAN is located on the left upper corner of the right atrium.
(iv) Stroke x Heart rate = Cardiac output.
During a cardiac cycle, each ventricle pumps out approximately 70 mL of blood which is called stroke volume. The stroke volume multiplied by the number of heart beats per minute (heart rate) gives the cardiac output. Therefore, Cardiac output = Stroke × heart rate =70×72=5040 mL per minute i.e., 5 litres per minute.
The problem of electrical discontinuity caused in the normal heart by the connective tissue separating the atria from the ventricles is solved by?
'X' is the rhythmic contraction and relaxation in the aorta and its main arteries. What is X?
Pulse is the rhythmic contraction and relaxation in the aorta and its main aeteries. It is a regular jerk of an artery. It is same as the heart rate because an artery pulses every time the heart beats.
The figure given below three stages in the cardiac cycle
In figure (2), blood is entering into the right auricle through superior and inferior vena cava and blood is entering into left auricle through pulmonary vein. Figure (1) shows movement of blood from the auricles into the ventricles. Figure (2) shows movement of blood from the right ventricle into the pulmonary artery and from the left ventricle into aorta.
A red blood cell, entering the right side of the heart passes by or through the following structures.
1. Atrioventricular valves
2. Semilunar valves
3. Right atrium
4. Right ventricle
Which of the following options represents the correct sequence?
Red blood cell (blood) will first meet SAN in the right atrium. Then from the right atrium it passes into right ventricle through atrio ventricular valve. From the right ventricle it enters into pulmonary artery through semilunar valve.
Consider the following four statements (i) - (iv) and select the correct option.
(i) SA node is natural pacemaker of heart.
(ii) Human heart has inter-auricular foramen.
(iii) Right atrioventricular valve is a semilunar valve.
(iv) Normal systolic and diastolic pressure of humans is 120 and 60 mm Hg respectively.
SA node is natural pacemaker of heart. Human heart has inter-auricular septum. Right atrioventricular valve a tricuspid valve is Normal systolic and diastolic pressured of humans is 120 mm Hg and 80 mm Hg respectively.
In the given figure the durations of the events of the cardiac cycle are given. Identify these events and select the correct option.
Duration of joint diastole is 0.4 sec, that of auricular systole is 0.1 sec and that of ventricular systole is 0.3 sec.
Right atrium receives blood from
Superior vena cava and inferior vena cava are the large veins. Superior vena cava brings deoxygenated blood from upper part of the body while inferior vena cava brings blood from lower part of the body into the right atrium of the heart.
What happens when the pacemaker becomes nonfunctional?
The SA node possesses a unique property of self-excitation, which enables it to act as the pacemaker of heart. It spontaneously generates a wave of contraction which spreads over both the auricles more or less simultaneously along the muscle fibres that fan out from the pacemaker. The pacemaker establishes the basic rhythm at which the heart beats. Thus, if the pacemaker becomes nonfunction, then the cardiac muscles do not undergo co-ordinated rhythmic movements.