heart
Definition
The heart is a muscular organ that pumps blood throughout the body. It is located in the chest, between the lungs. The heart is about the size of your fist.
The heart has four chambers: two atria and two ventricles. The atria are the upper chambers, and the ventricles are the lower chambers. The atria receive blood from the body, and the ventricles pump blood to the body.
The heart muscle is made up of cardiac muscle cells. Cardiac muscle cells are unique because they can contract and relax rhythmically. This allows the heart to beat continuously.
The heart is controlled by the nervous system and by hormones. The nervous system sends signals to the heart to make it beat faster or slower. Hormones, such as adrenaline, can also make the heart beat faster.
The heart is a very important organ. It is responsible for pumping blood to all parts of the body. If the heart stops beating, you will die.
There are many diseases that can affect the heart. Some common heart diseases include heart attack, stroke, and heart failure.
Heart disease is the leading cause of death in the United States. There are many things that you can do to reduce your risk of heart disease, such as eating a healthy diet, exercising regularly, and not smoking.
How can the word be used?
The heart beat of the patient increased as they became nervous.
Different forms of the word
Noun: heart.
Adjective: heartfelt.
Adverb: heartily.
Verb: hearten.
Etymology
The word "heart" has multiple etymologies, which are the sources of its different meanings.
The first etymology of "heart" is from the Old English word "heorte", which means "the centre of something". This is the origin of the meaning of "heart" as the centre of the body, or as the centre of something figurative, such as the heart of a city or the heart of a problem.
The second etymology of "heart" is from the Old English word "heortan", which means "to feel". This is the origin of the meaning of "heart" as the seat of emotions, or as the seat of courage or compassion.
Question
What is the heart made of?
AQA Science Exam Question and Answer
Question:
Explain the structure and function of the human heart, highlighting its role in the circulatory system and the importance of its coordinated pumping action.
Answer:
The human heart is a remarkable organ that serves as the central pump of the circulatory system. Structurally, it consists of four chambers: two atria and two ventricles. The right atrium receives deoxygenated blood from the body, which is then pumped into the right ventricle. From there, the blood is sent to the lungs for oxygenation. Oxygen-rich blood returns to the left atrium, followed by entry into the left ventricle. The left ventricle pumps oxygenated blood throughout the body.
The heart's coordinated pumping action is vital for maintaining circulation. The atria contract first, pushing blood into the ventricles. Subsequently, the ventricles contract, sending blood either to the lungs or the rest of the body. This rhythmic pumping is controlled by electrical signals that ensure proper timing and synchronisation of the heart's chambers.
The heart's efficient pumping action is essential for delivering oxygen and nutrients to body tissues and removing waste products. Any disruptions in this process can lead to serious health issues. Understanding the heart's structure and function helps us appreciate its central role in sustaining life and underscores the importance of adopting a healthy lifestyle to support its optimal performance.