Basic Introduction to Heart
In this, we will gain a basic understanding of the heart, its location, its functions, its structure, and the measures we may take to maintain its health…
Heart the Pumping Organ-
The heart is the most important component of your body’s circulatory system. The term “cardiovascular system” refers to the network of blood vessels and the heart. The heart’s primary function is to pump blood, which then nourishes and oxygenates the entire body.
A healthy heart provides the necessary amount of blood for the body to function properly. If the heart is compromised due to sickness or injury, the body’s organs will not receive adequate blood flow. Heart is muscular pumping organ. It is slightly larger than a fist and fully protected by the rib cage. A sophisticated network of blood vessels, transports blood from the heart to your body.
How do heart look and where it is present?
Everybody has a different-sized heart. Adult hearts are approximately the size of two clenched fists, but children’s hearts are approximately the size of one clenched fist. Heart proportions are 12 cm long, 8.5 cm wide, and 6 cm thick. The average weight of a human heart is 230–280 g for women and 280–340 g for men, though these numbers can vary widely depending on the individual.
The heart sits atop the diaphragm and is protected by the thoracic cavity located in the front of the chest, behind the sternum and coastal cartilage. It is found between the two lungs of your body, which occupy the left-angled lateral area known as pleural cavities. It is present to the left of the sternum.
Understanding about the parts of heart…
Your heart is surrounded by a double-layered tissue called pericardium. The pericardial cavity can be thought of as the space between the two layers. The pericardial fluid contained within this space serves to cushion the heart during contractions and prevent damage from occurring from movement or impact.
The pericardium controls heart movement. It lubricates, protects, and prevents acute volume overload in the heart.
What are the layers of the heart?
The different layers of the heart protect your heart, and restricts the expansion of the heart when your blood volume increases.
Three heart tissue layers are:
About chambers of heart-
Heart has 4 chambers which consist of two auricles and two ventricles. The amount of myocardium in each chamber of the heart determines its wall thickness, which in turn determines the amount of force that may be generated by that chamber.
Auricles- Atria are the two upper heart chambers. Thin-walled chambers receive blood from your veins. The left atrium receives oxygen-rich blood from the lungs, whereas the right atrium receives deoxygenated blood from the lower and upper bodies.
Right atrium is the heart’s upper chamber. The right atrium receives deoxygenated blood from the body during a cardiac cycle. When both atria are full, they contract and deoxygenated blood from the right atrium enters the right ventricle through the open triangle valve
Left atrium is the upper left cardiac chamber. Pulmonary veins carry oxygenated blood to the left atrium during a typical cardiac cycle. When full, both atria contract and oxygenated blood from the left atrium flows through the open mitral valve into the left ventricle.
Ventricles- The ventricles are the two chambers at the bottom of the heart. The two ventricles are chambers with thick walls that push blood out of the heart and into the lungs and other parts of your body.
Right ventricle is lower right heart chamber. When the right atrium contracts, deoxygenated blood enters the right ventricle. Right atrium valve closure fills right ventricle. Both ventricles constrict when full. Lungs receive right ventricle blood.
Left ventricle is the lower left cardiac chamber. When the left ventricle contracts, the mitral valve delivers oxygenated blood from the left atrium. The mitral valve closes and the aortic valve opens when the left ventricle contracts. Closing the mitral valve keeps blood from returning to the left atrium, while opening the aortic valve lets blood flow into the aorta and throughout the body.
What is heart septum?
The septum is a tissue that separates the left and right sides of your heart; it is located between the heart’s chambers. Septum’s primary function is to avoid the mixing of oxygenated and deoxygenated blood. Two septa are present in heart they are:
- Interatrial septum – The left atria is separated from the right atria through an interatrial septum,
- Interventricular septum – There is an interatrial septum between the left and the right ventricles.
What are heart valves?
The heart valves serve as gateways at the chamber entrances, opening and shutting to allow blood flow. Their fundamental responsibility is to ensure that blood flows in only one direction through the heart. The valves are well designed to tolerate any physical impact, including high blood pressure and velocity.
Heart mainly has 4 major valves:
The opening of the tricuspid valve facilitates the flow of blood from the right atrium to the right ventricles.
Mitral valve opening allows blood to flow from the left atrium to the left ventricle. The mitral valve allows oxygen-rich blood from the lungs to enter the left ventricle from the left atrium.
The aortic valve is the final valve through which oxygen-rich blood travels before leaving the heart and circulating throughout the body. The valve inhibits the return of blood to the left ventricle.
The pulmonic or pulmonary valve is the valve through which deoxygenated blood flows. It restricts the right ventricle and opens the pulmonary artery to allow blood flow to the lungs.
What do you mean by Heart Sound?
The valves of the heart open and close simultaneously to allow blood flow. The rapid closure of the valves causes the surrounding fluid to vibrate and creates heart sound.
They are of two types:
Lub– The first cardiac sound, or S1, is generated by the closure of the atrioventricular valves (mitral and tricuspid) at the start of ventricular contraction, or systole.
Dub– The second heart sound, or S2, is produced by the closing of Semilunar valves (aortic and pulmonary valves) at the end of ventricular systole.
What is the significance of Heart Sound?
It is valuable first line in patient’s evaluation. Abnormal heart sounds may be indicative of valve related heart problems. Murmurs are the sound produced by the backflow of blood due to ineffective valves.
Functioning and Working of heart?
The heart’s primary function is to maintain a steady blood flow throughout the body. Hence, the cells and tissues are supplied with oxygen and nutrients.
Significant functions of heart:
- It regulates the rhythm and rate of your heartbeat.
- It regulates the rhythm and rate of your heartbeat.
- The heart is also responsible for maintaining a healthy blood pressure level.
- There are two types of circulation within the body: pulmonary circulation and systemic circulation heart facilitates in both.
- In cooperation with other body systems, your heart regulates your heart rate and other bodily functions.
Steps involving blood flow-
The heart pumps oxygen- and nutrient-rich blood throughout your body with each beat. When blood returns to the heart, it is sent to the lungs for oxygenation. The heart subsequently pumps blood to the rest of the body, and the cycle repeats.
- Blood enters the right atrium from the superior and inferior vena cava.
- Blood from the right atrium flows through the right AV valve (tricuspid) into the right ventricle.
- Contraction of the right ventricle forces the pulmonary semilunar valve to open.
- Blood flows through the pulmonary valve into the pulmonary body.
- Blood is distributed through the right and left pulmonary arteries to the lungs, where CO2 leaves and loads oxygen.
- Blood returns from the lungs to the left atrium via the pulmonary veins.
- Blood from the left atrium flows through the left AV (mitral) valve into the left ventricle.
- Contraction of the left ventricle forces the aortic semilunar valve to open.
- Blood flows through the aortic valve into the ascending aorta.
- Blood from the aorta is distributed to every organ of the body, where it expels O and charges CO2.
- Blood returns to the heart from the vena cava.
Pacemakers are the heart tissues involved in pulse generation and heartbeat conduction.
Pacemaker tissue mainly consist of following basic parts:
- Sino Atrial Node (SA Node)
- Atrioventricular node (AV Node)
- Atrioventricular Bundle/ Bundle of His (AV Bundle)
- Purkinje Fibres
SA Node (Sino Atrial Node)
The SA node is responsible for maintaining a proper heart rate and rhythm by continuously producing electrical impulses. Thus, the SA node is known as the heart’s natural pacemaker. SA node is a thin, elongated, glycogen- and mitochondria-rich muscle fiber. It is situated near the confluence of the superior vena cava and right atrium. Generating electrical impulses at regular intervals to establish and sustain a steady heartbeat. SA node is also involved in heart rate regulation.
AV Node (Atrioventricular node)
It is regarded to be the heart’s secondary pacemaker. The AV node is a mass of specialized cells capable of self-excitation. Its principal role is impulse transmission to the ventricles. It can generate electrical impulses and conducts them from the heart’s atria to ventricles.
AV Bundle (Atrioventricular Bundle/Bundle of His)
Bundle of his commences at the AV node, which is a group of fibers that send electrical impulses through the center of the heart. The bundle of His is an extended segment connecting the AV node with the left and right bundle branches of the septal crest. The bundle of His is composed of a right and left branch. In the ventricles, both branches divide frequently to form a network of fibers.
Purkinje fibers come from the terminal divisions of the right and left His bundle branches to pierce the ventricular wall. They are greater in size and density than the SA node. Purkinje fibers have a big diameter and send impulses at a rapid rate.
How to keep your Heart Healthy?
Maintaining a healthy heart is crucial for excellent overall health and minimizing the risk of heart disease and other cardiovascular issues. Here are some heart-healthy practices:
- Healthy Diet: Consume a diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats. Limit your consumption of saturated and trans fats, sugars added to foods, and salt.
- Exercise frequently: Strive for at least 30 minutes of moderate-intensity activity on most days of the week. Examples include brisk walking, cycling, swimming, and dancing.
- Keep a healthy weight: Being overweight or obese increases the risk of heart disease. Aim to reduce weight through a combination of good nutrition and activity if you are overweight.
- Don’t smoke: Smoking is a big risk factor for cardiovascular disease and can cause damage to your blood vessels and heart. If you smoke, seek help to quit.
- Stress management is important since chronic stress can lead to high blood pressure and other heart issues. Discover methods of stress management, such as meditation, yoga, and deep breathing.
- Obtain sufficient rest: Strive for 7-9 hours of sleep per night. Sleep deprivation can increase the risk of hypertension, obesity, and other cardiac diseases.
- Keep an eye on your blood pressure and cholesterol levels. Excessive blood pressure and cholesterol might raise the risk of heart disease. Periodically check these levels and, if required, consult with your physician to manage them.
By adhering to these steps, you can maintain a healthy heart and lower your risk of heart disease and other cardiovascular complications.