The heart is one of the most crucial organs responsible for sustaining life. The heart is the pumping organ of the body. It helps transport blood to all the parts of the body. The heart pumps blood through the set of connections between veins and arteries. Throughout a person’s lifespan, the functioning of the heart is essential. Besides humans, most animals also have a heart, although their functioning isn’t the same. Today, here, we will discuss the cardiac cycle and Ventricular Systole in detail.
What is a Cardiac Cycle?
In simple terms, the cardiac cycle can be described as the process of alternating relaxation and contraction of ventricles and atria to pump blood across the body. The process starts with the beginning of a heartbeat and ends at the beginning of another one. It mainly includes systole, intervening pause, and diastole. The heart rate determines the occurrence of the entire cardiac cycle indicated naturally as beats every minute. The entire cardiac cycle begins at the 4th gestational week. This is the time when the heart first starts to beat the foetus.
In normal conditions, a human heart beats 72 times in a minute, which means that in 60 seconds, 72 cardiac cycles take place. This cycle involves both relaxation and contraction of ventricles and atria. One cycle only lasts for around 0.8 seconds.
Cardiac Cycle Phases
The cardiac cycle can be described as the process which starts with a heartbeat production to the commencement of the upcoming beat. This stimulus causes several events in the ventricles and atria. These events are organised in two different phases –
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Diastole is the phase where the heart is filled with blood.
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Systole is the phase where the heart pumps the blood.
Concept of Ventricular Systole
Ventricular Systole is the phase in the cardiac cycle where the ventricles get contracted. The electrical impulse comes at the AV node, also known as the atrioventricular node, shortly after atria get depolarized. At times, the AV node gets slightly delayed, giving the atria enough time to complete contracting before ventricles are depolarized. The action potential gets passed to the atrioventricular node under his bundle and to the right and left bundle branches.
These fibres have electrical impulses through different territories that lead to ventricular contraction. The pressure exceeds the atrium, leading to the atrioventricular valve’s closure as it starts to contract. Also, the pressure implied is not enough to open semilunar valves. Hence, the ventricles appear to be in the state of isovolumetric contraction.
What is Diastole?
Diastole is one of the three stages of the entire Cardiac Cycle. During this time, the blood gets recollected in the heart once it is emptied in the contraction stage. As mentioned earlier, In normal conditions, a human heart beats 72 times in a minute, which means that in 60 seconds, 72 cardiac cycles take place. It also means that completing the process of diastole requires only 0.5 sec, which includes refilling four chambers. Further, the diastole is classified into three significant terms – early rapid filling, diastasis and atrial contraction.
What are blood vessels in the body?
Blood Vessels are described as tube-like structures wherein the blood flows throughout the body. It is a group of connected vessels that allow the blood to flow through your body, known blood vessels. The two types of blood vessels present in a human body are:
Arteries: They help carry blood rich in oxygen from the heart to all parts of the body. The blood flows at a high speed and pressure through the arteries. This results in thick elastic walls for the arteries.
Veins: These types of blood vessels help carry blood that is carbon dioxide-rich from the body’s organs. They take it back to the heart. The veins have thin walls. They have valves that direct the blood towards the heart. The arteries are divided into smaller blood vessels. They are divided into further thinner tubes known as blood capillaries.
Conclusion
With this, we come to the end of the topic of Ventricular Systole in Biology. The heart is the pumping organ of the body. It pumps blood all the time. It helps in transporting blood to all the parts of the body. The heart pumps blood through the set of connections between veins and arteries. If the human heart spots its functioning, it can lead to sudden cardiac failure and untimely death. The cardiac cycle is the process that starts with a heartbeat production to the commencement of the upcoming beat. It mainly includes systole, intervening pause, and diastole. Diastole is one of the three stages of the entire Cardiac Cycle. During this time, the blood gets recollected in the heart once it is emptied in the contraction stage. As mentioned earlier, In normal conditions, a human heart beats 72 times in a minute. We hope the Ventricular Systole formula is clear to everyone.