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An Introduction to Cardiac Activity

MVSAT Dec 2023

To prevent the backward flow of blood from the ventricles into the atria, the atrioventricular (AV) valves (mitral and tricuspid valves) divide the two atria and ventricles. Aortic and pulmonary valves, on another side, are the semilunar valves that divide the ventricles from big arteries like the aorta and pulmonary artery to stop the backward flow of blood from arteries into the ventricles.

Semilunar valves are made up of cusps that are self-supported as a result of their unique structure and position within the arteries. While AV valves are made up of leaflets with specialised system support. The AV valves, which are attached to the ventricle walls through chordae tendineae prevent them from inverting, while in opposition to this, semilunar valves are fixed at the end of the aortic and pulmonary arteries.

What is Heartbeat?

It is a type of essential indicator of fitness within the human body. By understanding the heartbeat, we are able to measure the variety of times per minute that the heart beats. There is variation in the pace of the heartbeat due to bodily activity, threats to safety, and emotional responses. When someone is in a comfortable state, it is known as a resting heartbeat. In case any person has an ordinary heart rate, it no longer ensures that a person is free of fitness problems; it is a beneficial benchmark for figuring out a range of fitness issues.

Functioning of Normal Heart

The procedure of plumbing the coronary heart is carried out through a sequence of electrical impulses produced through a group of unique cells within the right atrium, known as the sinus node. The sinus node is known as a “natural pacemaker.” Production of pulses of electrical activity that unfolds through the coronary heart’s cells is carried out through the sinus node, which causes the coronary heart muscle to go through a contraction procedure.

The motion of an electrical impulse through the coronary heart is like the travelling of electricity via a circuit of fine wires. Impulses that are generated through sinus nodes travel down through the atria to special cells within the AV node. These impulses make the atria contract, and this procedure results in the squeezing of blood into the ventricles. Further, there's a transfer of impulse from the AV node through the ventricles through an electrical pathway. Those electric impulses cause the ventricles to contract and squeeze the blood from the coronary heart to the body frame and lungs.

Foetal Cardiac Activity

The cardiac activity in the foetus is in the range of 110 and 160 beats per minute. It can differ from 5 to 25 beats per minute. The foetal coronary heart rate may also change as your toddler responds to situations in your uterus. An abnormal foetal coronary heart rate can also additionally imply that your infant isn't getting sufficient oxygen or that there are some other problems. A foetal heartbeat can be first detected by a vaginal ultrasound as early as 5 1/2 to 6 weeks after the period of gestation. Then the first visible sign of a developing embryo can be seen. However, between 6 1/2 to 7 weeks after gestation, the heartbeat can be better evaluated.

Cardiac Activity in Pregnancy

When considering cardiac activity present in pregnancy during the gestation period, the heart rate increases from 110 bpm at the 5th week to 170 bpm at the 9th week in healthy foetuses. From then on, there is a continuous reduction in the heart rate that reaches a mean value of 150 bpm in the 13th week.

Regulation of Cardiac Activity

The regular activity of the human coronary heart is routinely regulated through the nodal tissues- the sinoatrial node (SA node) and atrioventricular node (AV node); therefore, the coronary heart is known as myogenic. Many physiological features are managed through the autonomic nervous system. It will increase the coronary heart’s contraction pressure and coronary heart rate. It additionally regulates blood vessel resistance on the periphery.

The sympathetic and parasympathetic divisions of the ANS work together to maintain the body frame in balance. The cardiac cycle promotes blood movement all through the frame. Two primary systems manage the cardiac cycle.

  • Intrinsic regulation of cardiac activity

  • Extrinsic regulation of cardiac activity

Interesting Facts

  • In a number of instances, the heartbeats per minute are the measurement of the coronary heart functioning.

  • The coronary heart rate of an individual needs to be in the range of 60 and 100 beats per minute even as they're resting after the age of ten years.

  • There is an increase in the heartbeat throughout an exercise.

  • An irregular heartbeat causes numerous heart problems.

  • As per present data, one in every 4 deaths in the United States happens due to coronary heart disease. So, the right monitoring of your coronary heart rate can help to prevent coronary heart complications or problems.

Important Question

  1. What are the benefits of cardio exercises?

Ans: 1. Improved heart health

2. Increased metabolism

3. Improved hormonal profile

4. Improved recovery ability

5. Management of diabetes

  1. What is the relationship between activity and heart rate?

Ans: During physical activity, if the heart rate is higher, then the exercise intensity will also be higher.

Key Features

  • The appearance of embryonic cardiac activity was studied in early human pregnancies set up through in-vitro fertilisation (IVF) and the use of transvaginal sonography.

  • Embryonic cardiac activity can be detected as early as 25 days after follicle aspiration. The appearance of embryonic cardiac activity in regular continuing pregnancies became five days and was not correlated with maternal age, day of embryo transfer, or cellular level at embryo transfer.

  • The difference in the appearance of embryonic cardiac activity is related to a difference in crown-rump length while the ensuing growth curve was ordinary; we ascribe those findings to distinct periods of the implantation level. The later cardiac activity becomes detected, the more chance of miscarriage.

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FAQs on Cardiac Activity

1. Why is the heartbeat known as intrinsic?

Cardiac cycle is regulated intrinsically through the nodal tissues. Heartbeat is known as intrinsic because it is initiated on the SA node, which is present in the right atrium.

2. What is abnormal heart rhythm?

Heartbeat or cardiac activity is not the only factor for determining good health. The rhythm of the heartbeat is also equally important. The heart should beat in a steady rhythm with a regular gap between the beats. Sometimes our heartbeat and rhythm both increase due to activities like exercise, anxiety, excitement and fear, which is known as abnormal heart rhythm.

3. What is the difference between heartbeat and heart rhythm?

The number of times our heart beats per minute is referred to as a heartbeat. It is likewise the number of times the heart pumps to push blood across the body.

The pattern wherein the coronary heartbeats are referred to as heart rhythm. It can be regular or irregular, or rapid or gradual, relying upon the features of the heart.

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