What is the cardiovascular system?
The backbone of the body’s supply chain is the transport network, also called the cardiovascular (circulatory) system. It is comprised of a central pumping unit, the heart, and a closed system of vessels, the arteries, veins, and capillaries. Together, these transport nutrients, oxygen, and essential materials from the blood to the surrounding cells. They also help to eliminate waste. Along the way, several checks and balances are in place to regulate the transportation of essential supplies to and from the cells.
In this blog, Gauze describes the relevance of our cardiovascular system, highlighting its anatomy (structure) and physiology (how it works). Let us dive into the topic.
Components of the cardiovascular system
The cardiovascular system delivers blood to various parts of the body and comprises
- The heart: A muscular organ that pumps blood to the body continuously.
- Blood vessels
- Arteries that carry blood from the heart
- Veins bring blood back to the heart
- Capillaries are tiny vessels that branch off from arteries and veins to deliver supplies to the blood tissue.
- Blood: The blood vessels contain blood, which is made up of plasma, red blood cells, white blood cells, and platelets
Types of circulation
- Systemic circulation: The circulatory system transports blood to organ tissues and cells in the body
- Pulmonary circulation: It occurs between the heart and lungs, which helps in the exchange of gases; oxygen enters the blood, and carbon dioxide leaves the blood
- Coronary circulation: Is the circulation in the heart itself. From the ascending aorta, the right and left coronary arteries supply the heart muscles and tissues. The cardiac veins then collect the venous blood into the coronary sinus.
Structure of the heart
The human heart consists of four chambers: two upper chambers, known as the atria, and two lower chambers, referred to as the ventricles.
A wall or septum separates the atria and ventricles, and valves present between the two control the flow of blood into different chambers.
How blood flows in the heart
- Inferior vena cava and superior vena cava veins bring deoxygenated blood (blood lacking in oxygen) from the body to the right atrium. The tricuspid valve between the right atrium and the right ventricle regulates the blood flow on the right side of the heart.
- From the right ventricle, the blood passes through the pulmonary valve into the pulmonary artery, then through the lungs.
- In the lungs, the blood gets oxygenated (becomes rich in oxygen).
- This oxygenated blood is pumped into the left atrium from the lungs via the pulmonary vein.
- The blood then flows through the mitral valve and enters the left ventricle.
- The left ventricle pumps the blood through the aortic valves to the aorta and to the rest of the body.
Working of the heart
The heart has an in-built electrical system that makes the upper chamber contract in a coordinated way. The sinoatrial node creates electrical signals that trigger a heartbeat.
The pathway of normal heart conduction
1. The sinoatrial (SA) node is the natural pacemaker of the heart, from where the heartbeat begins.
2. The atria contract as the impulse spreads through the atrial muscles
3. The atrioventricular (AV) node delays the signal to allow the ventricles to fill with blood
4. Bundle of His transmits the signals from the AV node to the ventricles
5. Right and left bundle branches transmit impulses down the side of the intraventricular septum
6. Purkinje’s fibers spread this impulse through the ventricular muscles into the ventricles and cause their contraction
Cardiac cycle
The heart works in two phases: the diastole and the systole
Diastole is the phase when the ventricles fill with blood. It begins with the closing of the aortic and the pulmonary valves, and ends when the ventricles begin to contract, just when the mitral or tricuspid valve closes
Systole is the second phase in which the ventricles contract and pump blood. It begins when the mitral or tricuspid valves close and ends with the closure of the aortic or pulmonary valves.
The pressure increases in the ventricles, pushing the blood into the blood vessels.
Importance of the circulatory system
- Provides oxygen and nutrients to body cells and tissues
- Removes waste products such as carbon dioxide and other metabolic wastes
- It transports hormones and chemicals
- Help in immune protection. The white blood cells fight infections and protect against diseases.
- Regulates body temperature
Common conditions of the cardiovascular system
Cardiovascular conditions can be life-threatening, so it is essential to prioritize our heart health.h
Heart attack
It occurs when the heart muscles have an insufficient blood supply
Symptoms of a heart attack are
- Chest pain
- Light headedness
- Pain radiating to the jaw, neck, or back
- Pain in one or both arms or shoulders
- Shortness of breath
The risk factors of a heart attack are
- High blood cholesterol
- High blood pressure
- Smoking
Stroke
When the blood supply to a part of the brain is cut off, a stroke occurs, which causes the death of brain cells.
Types of stroke
- An ischemic stroke is due to a blood clot blocking the blood flow to the brain.
- Hemorrhagic stroke occurs when there is a rupture of a blood vessel in and around the brain.
Risk factors of a stroke
- High blood pressure
- Diabetes
- Heart disease
- Smoking
- Family history
- Old age
Symptoms of a stroke:
- Weakness of the leg, arm, or face on one side
- Vision problem
- Confusion
- Slurry speech
- Dizziness
- Loss of balance
- Headache
Treatment depends on the type of stroke. Ischemic strokes are usually treated with medications. They help restore the blood flow to the brain. Haemorrhagic strokes require surgery.
Follow-up treatment requires anticoagulant medication, physical therapy, rehabilitation, speech therapy, and medications to lower BP.
Heart failure
It occurs when the heart is unable to pump blood to meet the body’s demands.
Symptoms
- Persistent coughing or wheezing
- Shortness of breath
- Difficulty in exercising
- Increased heart rate
- Nausea
- Swelling
- Fatigue
- Confusion
Risk factors are
- High blood pressure
- Coronary artery disease
- Obesity
- Heart attack
We can slow the progression of the condition, but no cure exists for heart failure. The only alternatives that help us are
- Lifestyle changes, which include diet and exercise
- Surgical procedures
- Medications
Arrhythmia
A heart may beat too fast (tachycardia) or too slow (bradycardia), both of which are arrhythmias.
Symptoms
- Fast or slow heartbeat
- Skip heartbeats
- Light headedness
- Dizziness
- Fainting
- Shortness of breath
- Sweating
- Chest pain
The risk factors are
- Heart disease
- Congenital heart defect
- High blood pressure
- Old age
- High cholesterol
- Alcohol consumption
The effects of aging on the cardiovascular system
The working efficiency of the heart decreases with increasing age. In old age, the heart rate slows down during physical activity, even though the resting heart rate remains steady.
Aging causes high blood pressure, heart attack, stroke, and heart failure.
Lifestyle changes for a healthy cardiovascular system
Certain lifestyle changes go a long way in managing the cardiovascular system. They are
- Do regular physical activity
- Take 7-8 hours of sleep at night
- Manage your blood pressure, cholesterol, weight, and stress.
- Avoid tobacco and alcohol
- Eat a balanced diet
Conclusion
The cardiovascular system is important for life, as it supplies oxygen, nutrients, and other essential substances to our body, and removes waste, helping us stay active and healthy. When problems occur, we face life-threatening situations such as a heart attack, stroke, and heart failure. The risk of developing heart disease can be reduced by quitting smoking, eating a healthy diet, and engaging in regular physical activity, all of which depend on our daily choices. Although medical advances aid in early diagnosis, prevention remains the most powerful tool we have at our disposal. Taking care of our heart health today not only protects our health but also impacts our longevity.
Here to answer all your questions
Early signs of heart disease are shortness of breath, chest pain, and palpitations.
It is because men have more risk factors, such as smoking and high blood pressure, compared to women, who are protected by hormones. However, women catch up after menopause.
Cholesterol is a soft, waxy substance produced in the liver and found in foods such as egg yolks, milk fat, and meat.
Consuming excess salt increases blood pressure and poses a risk of developing heart disease. We should limit our daily salt intake to no more than 2,300 milligrams.
It is because men have more risk factors, such as smoking and high blood pressure, compared to women, who are protected by hormones. However, women catch up after menopause.
Blood cells, proteins, and platelets clump together to form a clot, which stops the bleeding. Sometimes, a clot forms when it shouldn’t, and it breaks down, leading to health issues. Some common causes include injury to blood vessels, sedentary habits, and genetic factors, as well as obesity, smoking, pregnancy, and certain medications, which also increase the risk of blood clot formation.
