Annelids and Their Characteristics

These flashcards cover key concepts related to annelids including segmentation, coelom, habitat, locomotion, and medical applications.

What is segmentation in animals?

It is the division of an animal's body into repeated segments.

In segmented animals, what separates many repeated organ systems (e.g., excretory, circulatory)?

Septa.

What type of segmentation do annelids exhibit, where their segments are similar to one another?

Homonomous segmentation.

What type of symmetry do annelids have?

Bilateral symmetry, characterized by a left-right mirror plane.

Why are annelids classified as true coelomates?

Because their internal cavity is entirely lined by mesoderm.

How does gas exchange occur in many annelids?

Through the skin.

What is the singular form of 'setae'?

Seta.

In terrestrial annelids, how do setae help with movement?

They help to anchor segments against the substrate to prevent sliding.

What two factors are involved in the coordinated, segmental movement of earthworms?

Hydrostatic pressure and muscle action.

What type of wave movements do earthworms use to advance?

Peristaltic wave movements, where contraction waves move from head to tail.

What is characteristic of septa in leeches?

They are often reduced or absent between their segments, and some segments are fused.

What term describes leeches that consume blood from their hosts?

Hematophagous feeders.

In modern medicine, for what purpose are leeches used in microsurgery?

To relieve venous congestion.

What is the name of the anticoagulant secreted by leeches that helps to keep blood flowing?

Hirudin.

What is segmentation in animals?

It is the division of an animal's body into repeated segments.

In segmented animals, what separates many repeated organ systems (e.g., excretory, circulatory)?

Septa.

What is the function of septa in many segmented animals?

To separate repeated organ systems, such as excretory and circulatory systems.

What type of segmentation do annelids exhibit, where their segments are similar to one another?

Homonomous segmentation.

Describe the characteristic of segments in homonomous segmentation.

They are similar to one another.

What type of symmetry do annelids have?

Bilateral symmetry, characterized by a left-right mirror plane.

Why are annelids classified as true coelomates?

Because their internal cavity is entirely lined by mesoderm.

What anatomical feature defines a true coelomate?

An internal cavity entirely lined by mesoderm.

How does gas exchange occur in many annelids?

Through the skin.

What is the singular form of 'setae'?

Seta.

In terrestrial annelids, how do setae help with movement?

They help to anchor segments against the substrate to prevent sliding.

What two factors are involved in the coordinated, segmental movement of earthworms?

Hydrostatic pressure and muscle action.

What type of wave movements do earthworms use to advance?

Peristaltic wave movements, where contraction waves move from head to tail.

How do earthworms generate forward movement using peristaltic waves?

Contraction waves move from head to tail.

What is characteristic of septa in leeches?

They are often reduced or absent between their segments, and some segments are fused.

What term describes leeches that consume blood from their hosts?

Hematophagous feeders.

In modern medicine, for what purpose are leeches used in microsurgery?

To relieve venous congestion.

What specific medical condition are leeches used to treat in microsurgery?

Venous congestion.

What is the name of the anticoagulant secreted by leeches that helps to keep blood flowing?

Hirudin.

What is the primary role of hirudin secreted by leeches?

It acts as an anticoagulant, helping to keep blood flowing.