Question

How much nervous system does an echinoderm have? Sea stars have:

a. Central nervous system
b. Peripheral nervous system
c. Simple nerve net
d. No nervous system

Answer 1

Sea stars have a simple nerve net rather than a centralized nervous system, consisting of a circumoral nerve ring and radial nerves extending along their arms.

Step-by-step explanation:

The nervous system of echinoderms, such as sea stars, is quite simple. It includes a circumoral nerve ring and radial nerves extending along the arms. Unlike some other invertebrates, echinoderms do not have a centralized nervous system such as a brain or large ganglia. While they may have well-developed sensory organs for touch, chemoreception, and photoreception, their nervous system can best be described as a simple nerve net.

Their nerve cells are bundled into fibers called nerves, and they have sensory cells on their body surface for chemical detection. Echinoderms like sea stars also utilize their nervous system along with their unique water vascular system to move and capture food.