Please summarize the key points from the following text about the structure and role of the human heart:

The human heart is a muscular organ that pumps blood through the body's circulatory system. It is located in the chest cavity between the lungs, behind the sternum.  Shaped like an upside-down pear, the heart is made up of four chambers - two upper atria and two lower ventricles. 

The right atrium receives deoxygenated blood from the body and pumps it into the right ventricle, which then sends it to the lungs to be oxygenated. The oxygenated blood returns to the left atrium, flows into the left ventricle, and is then pumped out to the body through the aorta - the main artery leaving the heart.

The walls of the heart are composed of cardiac muscle, and the interior is lined with endocardium. The heart has four valves that control the direction of blood flow - the tricuspid, pulmonary, mitral, and aortic valves. Electrical impulses from the sinoatrial node cause the heart to contract and pump blood in a continuous cycle.  

On average, the human heart beats around 100,000 times per day, pumping about 2,000 gallons of blood through an estimated 60,000 miles of blood vessels in the body. Proper heart function is essential for transporting oxygen, nutrients, and other vital substances throughout the body.
Please summarize the key points from the following text about the structure and role of the human heart:

The human heart is a muscular organ that pumps blood through the body's circulatory system. It is located in the chest cavity between the lungs, behind the sternum.  Shaped like an upside-down pear, the heart is made up of four chambers - two upper atria and two lower ventricles. 

The right atrium receives deoxygenated blood from the body and pumps it into the right ventricle, which then sends it to the lungs to be oxygenated. The oxygenated blood returns to the left atrium, flows into the left ventricle, and is then pumped out to the body through the aorta - the main artery leaving the heart.

The walls of the heart are composed of cardiac muscle, and the interior is lined with endocardium. The heart has four valves that control the direction of blood flow - the tricuspid, pulmonary, mitral, and aortic valves. Electrical impulses from the sinoatrial node cause the heart to contract and pump blood in a continuous cycle.  

On average, the human heart beats around 100,000 times per day, pumping about 2,000 gallons of blood through an estimated 60,000 miles of blood vessels in the body. Proper heart function is essential for transporting oxygen, nutrients, and other vital substances throughout the body.
user
The human heart is a muscular organ that pumps blood through the circulatory system. It has four chambers - two atria that receive blood and two ventricles that pump it out. Deoxygenated blood enters the right atrium, goes to the right ventricle and lungs for oxygenation, then returns to the left atrium and ventricle, which pumps oxygenated blood out to the body through the aorta. The heart is made of cardiac muscle with valves controlling blood flow direction. Electrical impulses cause it to contract and pump blood continuously, beating around 100,000 times per day to transport oxygen and nutrients via the blood vessels.
assistant
Generate a series of (instruction, response) pairs that are similar in context and structure to the example provided below. Each pair should consist of a concise instruction followed by an appropriate, detailed response. The instruction should pose a clear task or question, while the response should provide a comprehensive answer or solution that could be understood by someone with a basic understanding of the subject.

Example pair: 
Instruction: Please write a summary, in simple language, of who Daisy Eagan is using the following:

Throughout her multi-decade career, Tony award-winner Daisy Eagan has dazzled audiences from the stage to television and film, and with her writing. Next stop – time to take over the podcast world.
 
At age eleven, Eagan became the youngest actress to win a Tony Award for Best Performance by A Featured Actress for playing Mary Lennox in “The Secret Garden.” In 2016, Eagan returned to “The Secret Garden” to play Martha for the 25th anniversary concert production at Lincoln Center and at the Shakespeare Theatre in Washington, DC. Eagan also appeared on Broadway in “Les Miserables” and “James Joyce's The Dead,” and most recently on stage she starred in the First National Tour of Stephen Karam’s Tony-winning play, “The Humans.”
 
On television, Eagan can be seen on Freeform’s critically-acclaimed series “Good Trouble.” Additional television credits include HULU’s “The Path,” HBO’s “Girls,” CBS’ “The Mentalist,” “Without a Trace,” “Ghost Whisperer,” “The Unit” and “Numb3rs.”
 
A published award-winning writer with a loyal and growing audience, Eagan is a fierce fighter and activist for women's and LGBTQ rights. She is a rousing voice in political arenas and continues to fight for change throughout her literary career. She has written op-eds for publications including HuffPost and Playbill.com and had a column for USA Today Network’s The Journal News.
Response: Daisy Eagan is an award-winning stage and television actress, writer, and activist, and now can add podcaster to her list of roles. At only 11 years old, she won a Tony Award, she was the youngest actress to win such a prestigious award. She has appeared in several TV series, including The Path, Girls, and The Mentalist. Eagan is also an award-winning writer, activist, and a rousing voice in politics. 

Your task is to generate more pairs that maintain this level of clarity and detail. The topic is Summarization. Write a long text of instruction by yourself, then summarize the given instruction in a response. Ensure that the responses are informative and accurate, suitable for an educational context. 

Store the generated pairs in valid JSON format, with each pair as an object within an array. Each object should have two key-value pairs: "instruction" and "response". For instance: 

{"contents": [{"instruction": "text", "response": "text"}, {"instruction": "text", "response": "text"}, ...]} 

Remember to maintain consistency in the format and ensure the generated pairs are diverse and cover a broad range of subjects. You must return the response in the asked format and you must not add any additional text in your response.
