Hard tissue

Hard Tissue

Hard tissue, in the context of anatomy, refers to the group of tissues in the body that are physically hard. This includes bone and tooth enamel, which are primarily composed of minerals.

Etymology

The term "hard tissue" is derived from the Old English word "heard," which means "not soft, firm, solid, stiff." The word "tissue" comes from the Old French "tissue," which means "a weaver's beam," and from the Latin "texere," which means "to weave."

Types of Hard Tissue

There are two main types of hard tissue in the human body: bone and tooth enamel.

Bone

Bone is a rigid organ that constitutes part of the vertebrate skeleton. Bones support and protect the various organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have a complex internal and external structure.

Tooth Enamel

Tooth enamel is one of the four major tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the crown. The other major tissues are dentin, cementum, and dental pulp. It is a very hard, white to off-white, highly mineralized substance that acts as a barrier to protect the tooth but can become susceptible to degradation, especially by acids from food and drink.

Related Terms

• Dentin: The hard, dense, bony tissue forming the bulk of a tooth beneath the enamel.
• Cementum: A specialized calcified substance covering the root of a tooth.
• Dental Pulp: The part in the center of a tooth made up of living connective tissue and cells called odontoblasts.

See Also

• Soft Tissue
• Connective Tissue
• Skeletal Tissue