Hemal system

Definition

The hemal system is a network of blood vessels and sinuses involved in the circulation of fluids in some invertebrates, particularly within the superphylum Deuterostomia. It functions similarly to the circulatory system in vertebrates but is less complex and often lacks a distinct heart.

5 Must Know Facts For Your Next Test

1. The hemal system is found in echinoderms such as sea stars and sea urchins.
2. It is involved in transporting nutrients, gases, and waste products throughout the organism's body.
3. The hemal system works closely with the water vascular system to facilitate movement and feeding.
4. In some species, it includes hemal rings that encircle various parts of the body for distribution of fluids.
5. Unlike vertebrate circulatory systems, the hemal system often lacks specialized cells for oxygen transport.

Related terms

Water Vascular System: A hydraulic network used by echinoderms for locomotion, food and waste transportation, and respiration.

Echinodermata:

A phylum within Deuterostomia that includes marine animals such as sea stars, sea cucumbers, and sand dollars.

Coelom:

A fluid-filled body cavity found within many animals which can also play a role in circulation and transport of nutrients.