Tubular heart

Tubular heart is a type of heart structure found in some invertebrates, including insects and arachnids. The heart is a long, tube-like organ that pumps hemolymph, the invertebrate equivalent of blood, throughout the body.

Etymology

The term "tubular heart" comes from the Latin tubulus, meaning "a small tube", and cor, meaning "heart". This reflects the heart's tube-like structure.

Structure and Function

The tubular heart is a long, slender organ that extends along the length of the body. It is composed of a series of segmentally arranged pumps, each of which can function independently. The heart pumps hemolymph, the invertebrate equivalent of blood, throughout the body. Hemolymph is circulated through the body cavity, or hemocoel, delivering nutrients and oxygen to the body's cells.

The tubular heart is contractile, meaning it can contract and expand to pump hemolymph. The heart's contractions are coordinated by a series of pacemaker cells, which generate electrical signals that trigger each contraction.

Comparison with Other Heart Types

Unlike the four-chambered heart found in mammals, the tubular heart is a single, continuous tube. This makes it more similar to the two-chambered heart found in fish and some amphibians. However, the tubular heart's structure is unique among animal hearts, reflecting the diverse range of heart types found in the animal kingdom.

Related Terms

• Hemolymph: The invertebrate equivalent of blood, which is pumped by the tubular heart.
• Hemocoel: The body cavity through which hemolymph is circulated.
• Pacemaker: Cells that coordinate the contractions of the tubular heart.

See Also

• Invertebrate heart
• Arthropod heart
• Circulatory system