Which one of the following is mainly responsible for the second heart sound?
Closure of atrioventricular valves
Opening of atrioventricular valves
Closure of semilunar valves
Thrust of blood on ventricular wall during atrial contraction
C.
Closure of semilunar valves
The first heart sound Lubb' is produced at the onset of ventricular systole, when the atria-ventricular valves (tricuspid and bicuspid) close. At the beginning of ventricular diastole, the semilunar valves close, producing the second heart sound 'dup'.
The vein which is formed from the capillaries of an organ and terminates into capillaries in some other organ before entering the heart is called
pulmonary vein
coronary vein
portal vein
systemic vein
Choose the right sequential phenomena among the following during the delivery of O2 from blood to tissue.
I. Absorption of CO2 by the blood.
II. Reaction of absorbed CO2 with H2O to form H2CO3 within RBC and its conversion into H+ and HCO3- ions.
III. Reaction of absorbed CO2 with H2O in plasma to form H2CO3 and its conversion into H+ and HCO3- ions.
IV. Combination of H+ with haeme portion of HbO2 to release O2.
V. Combination of HCO3- with haeme portion of HbO2 to form reduced haemoglobin and release of O2.
I, II and V
I, III and IV
I, II and IV
I, III and V
Match the items in column I with those in column II and choose the correct answer.
Column I | Column II |
A. Electroencephalography | 1. A graphic recording of the electrical activity of heart |
B. Electrocardiography | 2. A graphic recording of the electrical activity of brain. |
C. Endoscopy | 3. A technique that gives image automatically in multiple planes. |
D. MRI | 4. To view within th body without cutting through the overlaying tissues. |
A- 2; B- 1; C- 4; D- 3
A- 4; B- 2; C- 3; D- 4
A- 1; B- 3; C- 2; D- 4
A- 3; B- 4; C- 1; D- 2
Figure shows schematic plan of blood circulation in human with labels - A to D. Identify the label and give its function/s.
A - pulmonary vein - takes impure blood from body parts, pO2 = 60 mmHg
B - pulmonary artery - takes blood from heart to lungs, pO2 = 90 mmHg
C - vena cava - takes blood from body parts to right auricle, pCO2 = 45 mmHg
D - dorsal aorta - takes blood from heart to body parts, pO2 = 95 mmHg
The diagram given here is the standard ECG of a normal person. The P - wave represents the
contraction of both the atria
initiation of the ventricular contraction
beginning of the systole
end of systole
Which valve is present at the opening of coronary sinus?
Mitral valve
Eustachian valve
Thebesian valve
Tricaspid valve
Which blood cells can engulf bacteria by phagocytosis?
Eosinophil and basophil
Basophil and lymphocyte
Neutrophil and monocyte
Neutrophil and lymphocyte
Which of the following factor(s) increase blood pressure?
Increase of cardiac output
Constriction of blood vessel
Activation of parasympathetic nerve
Increase of blood volume