What is the cardiovascular system
Cardiovascular organs
The cardiovascular system consists of the heart that pumps blood and supplies it all over the human body. The blood travels through the blood vessels present throughout the body. The heart weighs 148-296 grams in females, and 233-383 grams in males.1,2 The heart makes up 5% of the overall body weight and is present in the mediastinum enclosed in the pericardial sac. Overall, the cardiovascular system includes the blood, the blood vessels, the heart, and the lymphatic system.3
Heart
The heart is a muscular organ, made up of the pericardia that function to pump blood to the lungs and collect blood from the tissues. The pathway of blood flow is through the chambers present in the heart. The chambers are the atrium and the ventricles, the blood is transported into the atrium via the superior and inferior vena cava.3
Blood
Blood helps in the transportation of gases (oxygen, carbon dioxide), nutrients, waste, hormones, regulation of blood pH, temperature, and protection against foreign particles. There are several elements present in the blood that forms it, red blood cells (RBC) and white blood cells (WBC), these elements are formed in the red bone marrow. Hemoglobin is the protein that binds with oxygen and transports it across the body. The total volume of blood in a normal human is approx. 5.5 liters.3
Systemic circulation: The circulation helps to transport blood from the heart to the tissues of the body and returns to the heart. Oxygenated blood travels from the left ventricle and reaches the ascending aorta, from which the blood is supplied towards the neck, the head, and the upper body, and from the descending aorta, the blood travels to the abdomen and lower body. In the systemic circulation, oxygen (O2) is exchanged from carbon dioxide (CO2) resulting in the formation of deoxygenated blood (oxygen-poor). The deoxygenated blood travels to the right atrium via the inferior and superior vena cava.
Pulmonary circulation: The circulation helps to transport blood from the heart to the lungs for gas exchange and then returns it to the heart. The deoxygenated blood travels from the right ventricle towards the pulmonary trunk, and then gets divided into the left and right pulmonary arteries from where the blood travels towards the left and right lungs, and in pulmonary capillaries exchange of gases takes place.
Blood
Blood flows via blood vessels throughout the body. The smallest branch of the blood vessel is known as the capillary. Around 5% of total blood circulation takes place in the capillaries. Metabolic activities take place in the capillaries like gas exchange. The inner diameter of capillaries ranges from 5-10um, while blood vessels are 5um. The blood circulation in the human body is like a closed-loop system.3
Lymphatic system
The Lymphatic system consists of various tissues and capillaries. It produces a fluid known as lymph, it contains two elements T and B lymphocytes. The lymphatic node is one of the major routes for nutrient absorption and fatty substance absorption.3
Factors affecting the heart
Hypertension: It is a sustained elevation of systemic arterial pressure. Excessive intake of salt affects systemic arterial pressure, and factors like excess calcium in the blood can cause hypercalcemia.
Arteriosclerosis: It is a vascular disorder that results in the thickening and hardening of the blood vessel wall. This takes place due to the presence of fatty materials and blood clots which block the way for the blood flow this can also cause a heart attack or mini heart attack.4
Ischemic heart disease (IHD): IHD is caused due to the presence of plaque in the artery, and due to the dysfunction of the left ventricle which leads to heart failure (HF).5
Blood pressure: The blood pressure depends on the force of the blood flow against the inner wall of the blood vessels, which is managed by alternating heart rate and blood volume, if the heart rate and blood volume increase the pressure increases and vice versa. The normal blood pressure is 120/80mmHg. Blood pressure is determined by the baroreceptors present in the vasomotor center. The vasomotor center influences the heart rate.6
Diabetes: It affects patients’ health during adulthood and old age and can lead to heart disease. There are two types- type 1 diabetes and type 2 diabetes. Type 2 directly affects the heart.7
Preventive factors
- Reducing the consumption of tobacco and alcohol decreases the mortality rate of ischemic heart disease (IHD)
- Regular exercise helps in controlling weight and obesity, it also helps to keep our heart rates stable.
- Avoiding high cholesterol and fatty substances, and intake of nutritious fruits and vegetables lead us to a healthy quality of life
- Dairy food like calcium and vitamin D reduces cardiovascular disease risk, and potassium and magnesium(spinach) help to maintain blood pressure/ hypertension8
Summary
The heart is the most important organ of the body. Blood pumps and travels all over the body via the heart. Within the heart, several organs help to transport blood to the tissues and the organs. Arteries, veins, and capillaries play an important role in the circulation of blood. Hearts should always be healthy and to keep them healthy one should not consume tobacco, and alcohol and avoid smoking. Several risk factors affect the heart like high blood pressure, thickening of arteries due to fatty deposits, hypertension, and many more. To avoid all these, one should eat healthy, exercise, and avoid all the risk factors.
People dealing with heart disease should always consult a doctor and visit the nearest hospital and should not consume drugs without a prescription.
References
- Molina DK, DiMaio VJM. Normal Organ Weights in Women: Part I—The Heart. The American Journal of Forensic Medicine and Pathology. 2015;36(3):176-81.
- Molina DK, DiMaio VJM. Normal Organ Weights in Men: Part I—The Heart. The American Journal of Forensic Medicine and Pathology. 2012;33(4):362-7.
- Weinhaus AJ, Roberts KP. Anatomy of the human heart. Handbook of cardiac anatomy, physiology, and devices: Springer; 2005. p. 51-79.
- Wilson A. Heart-attack: Causes and Preventions. International Journal of Clinical Skills. 2021;15(5):182.
- Severino P, D’Amato A, Pucci M, Infusino F, Birtolo LI, Mariani MV, et al. Ischemic heart disease and heart failure: role of coronary ion channels. International Journal of Molecular Sciences. 2020;21(9):3167.
- Levick JR. An introduction to cardiovascular physiology: Butterworth-Heinemann; 2013.
- Chatterjee S, Khunti K, Davies MJ. Type 2 diabetes. The lancet. 2017;389(10085):2239-51.
- Tips-Don’t Skip A. Dairy Good Foods For Your Heart.
