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Enamel is the hardest substance in the human body and contains the highest percentage of minerals, [3] 96%, with water and organic material composing the rest. [4] The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. [5] Enamel is formed on the tooth while the tooth is developing within the gum, before it erupts into ...
Enamel is the hardest substance in the human body and contains the highest percentage of minerals (at 96%), [2] with water and organic material composing the rest. [3] The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. [4]
Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...
The four organogenic elements, namely carbon, hydrogen, oxygen, and nitrogen , that comprise roughly 96% of the human body by weight, [7] are usually not considered as minerals (nutrient). In fact, in nutrition, the term "mineral" refers more generally to all the other functional and structural elements found in living organisms.
Cross-section of a tooth. B is dentin. Dentin (/ ˈ d ɛ n t ɪ n / DEN-tin) (American English) or dentine (/ ˈ d ɛ n ˌ t iː n / DEN-teen or / ˌ d ɛ n ˈ t iː n / DEN-TEEN) (British English) (Latin: substantia eburnea) is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth.
Human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. [1] Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food ...
Microscopy of keratin filaments inside cells. Keratin (/ ˈ k ɛr ə t ɪ n / [1] [2]) is one of a family of structural fibrous proteins also known as scleroproteins.It is the key structural material making up scales, hair, nails, feathers, horns, claws, hooves, and the outer layer of skin in vertebrates.
The human body is the entire structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organs and then organ systems . The external human body consists of a head , hair , neck , torso (which includes the thorax and abdomen ), genitals , arms , hands , legs , and feet .