Act 13: Invertebrates Protection, Support, and Movement

• Invertebrates are soft bodied animals.
• Hydroskeleton - fluid filled skeleton.
• Hydroskeleton determines shape and mobility of invertebrates like earthworms, annelids, echinodermata.
• Integument/exoskeleton - hardened but flexible covering.
• Epidermis - responsible for formation of chitinous cuticle.
• Cuticle - protection against body surface water loss
• 3 layers: epicuticle, exocuticle, endocuticle.
• Epicuticle - thin non chitinous
• Exocuticle - dense chitin-protein structure.
• Shells are composed of calcium carbonate.
• Movement is possible due to contraction and relaxation of muscles.
• Columellar muscles - soft parts of gastropod body held in place in the shell
• Adductor muscle - controls opening and closing of shells.
• Insect flight muscles are cross striated muscles.
• Direct flight - wing muscles are inserted directly at the wing bases.
• Direct flight - fast movement of wings
• Indirect flight muscle slow wing movement
• Dorsoventral and dorsolongitudinal muscles in Indirect flight.
• Muscles are attached in thorax in indirect flight.
• What parts of cockroach leg are involved in movement? Coxa and Trochanter as base for leg movement. Femur and Tibia for muscles that contract and relax.