Atoms in a human body
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Distribution of Atoms in the Human Body
Key Elements: Carbon, Oxygen, Hydrogen, and More
The human body is composed of a variety of atoms, with carbon, oxygen, and hydrogen being the most abundant. These elements are distributed throughout the body in a non-random manner, reflecting their roles in different biological functions. For instance, bones and teeth are rich in phosphorus and calcium, while hair contains significant amounts of sulfur and nitrogen1. This preferential distribution is crucial for the body's structural and functional integrity.
Atomic Composition and Measurement Techniques
Human body composition can be analyzed at multiple levels, including the atomic level. Six key elements—carbon, nitrogen, calcium, potassium, sodium, and chlorine—can be measured directly in vivo using neutron-activation systems. This method allows for the quantification of major chemical components at the molecular level, providing insights into the body's chemical composition and its changes with aging2.
Historical Perspective on Atomic Theory
The concept that the world, including the human body, is composed of atoms has evolved over centuries. From the early ideas of the Ancient Greeks to the chemical experiments of the 19th century, and finally to Albert Einstein's interpretation of Brownian motion in 1905, the atomic hypothesis has become a fundamental principle in understanding matter3.
Molecular Arrangements and Biological Functions
Atoms in the human body are not just randomly scattered; they are organized into molecules that perform specific functions. For example, proteins, which are made up of long chains of amino acids, play various roles in different organs. Keratins, a type of protein found in hair, are arranged in long, narrow molecular structures that align with the hair's axis, contributing to its strength and flexibility1.
Effective Atomic Numbers in Human Tissues
The effective atomic number is a concept used to describe the interaction of photons with human tissues. This number varies slightly among different tissues but is relatively consistent within soft tissues across a range of photon energies. For bones, the effective atomic number varies more significantly due to their different chemical compositions5.
Conclusion
The human body is a complex assembly of atoms and molecules, each playing a specific role in maintaining life. From the preferential distribution of elements like carbon, oxygen, and hydrogen to the intricate molecular arrangements in proteins, the atomic composition of the body is both diverse and highly organized. Advanced measurement techniques, such as neutron-activation analysis, provide valuable insights into these atomic and molecular structures, enhancing our understanding of human biology.
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Most relevant research papers on this topic
Body composition and aging: a study by in vivo neutron activation analysis.
In vivo neutron activation analysis provides an important opportunity to study the relationship between aging and changes in human body composition, including the validity of two-compartment indirect methods for quantifying total body fat in the elderly.
2. Atoms
The discovery of atoms, despite their invisibility, was a key milestone in the understanding of matter and its properties.
Many-body physics with individually controlled Rydberg atoms
Individually controlled Rydberg atoms, when excited to Rydberg states, offer a promising platform for quantum simulation of many-body physics, particularly for spin systems.
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