8 public questions tagged with this topic.
The AV node slows down the electrical signal from the SA node before sending it to the ventricles, allowing the atria to contract first.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation Circulatory System - Comparative and Evolutionary Aspects
The QRS complex represents ventricular depolarization, leading to ventricular contraction.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation ECG and Blood Vessels
The cardiac cycle consists of systole (contraction) and diastole (relaxation) of the heart chambers.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation Human Heart - Structure and Cardiac Cycle
The first heart sound "Lub" is caused by the closure of the atrioventricular (AV) valves.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation Human Heart - Structure and Cardiac Cycle
Not all arteries carry oxygenated blood. The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation Human Heart - Structure and Cardiac Cycle
The pulmonary valve prevents backflow of blood into the right ventricle after it enters the pulmonary artery.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation Human Heart - Structure and Cardiac Cycle
The duration of one complete cardiac cycle is about 0.8 seconds in a healthy adult.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation Human Heart - Structure and Cardiac Cycle
The circulatory system transports hormones but does not synthesize them; hormones are produced by endocrine glands.
Ref: NCERT Class 11 Biology Chapter 15: Body Fluids and Circulation Lymph and Circulatory Pathways
