Skeletal System Packet 37 Saturday September 25 2021

Skeletal System Packet #37 Saturday, September 25, 2021 1

The Skeletal System n The skeletal system has three main functions n n Protection Support Movement Additionally, the skeleton can come in three different forms n n n Protection Hydrostatic skeleton Exoskeleton Endoskeleton Saturday, September 25, 2021 Functions Support Movement Skeletal System Hydrostatic Skeleton Forms Exoskeleton Endoskeleton 2

Hydrostatic Skeleton n Consists of fluid held under pressure in a closed body compartment n n Cnidarians Flatworms Earthworms Move by using muscles to change the shape of the fluid filled compartments Saturday, September 25, 2021 Cnidarians Hydrostatic Skeleton Flatworms Earthworms 3

Exoskeleton n Hard encasement deposited on the surface of an animal n Mollusks n n Kingdom Animalia Phylum Mollusca n n n Snails Oysters Slugs Snails Exoskeletons-Mollusks Oysters Slugs Saturday, September 25, 2021 4

Endoskeleton n Endoskeletons n Consists of hard supporting elements, such as bones, buried within soft tissues of an animal. n Humans n n Axial Skeleton n Skull n 8 cranial bones n 14 facial bones n Vertebral column (backbone) n Rib cage n 7 pairs of true ribs n 3 pairs of false ribs n 2 pairs of floating ribs Appendicular Skeleton n Limb bones n Pelvic girdles Saturday, September 25, 2021 5

Review n Students create, and review, their own charts Saturday, September 25, 2021 6