Skeletal System Unit 4

Skeletal System Functions A.Protection* B.Support* C.Movement D.Calcium Store E.Make Blood *Not possible without Calcium, bones would be too brittle!

Tiny Tidbits There are 206 bones in the body Largest bone is the femur (thigh bone) Smallest bones in the ear o Incus o Malleus o Stapes Marrow: creates blood stem cells that make all formed units in the blood (in the core of long bones) Suture: type of joint that only occurs in the skull o Unfused at birth (“soft spots”), allows for some movement

Bone Marrow Location and Donation

Sutures Infant to Adult

4 Types of Bones in the Body Long-longer than wide Ex: Arm/Leg Short- Roughly cube shaped Ex: Tarsals/Metatarsals Flat –thin, generally curved Ex: Sternum/Ribs Irregular-complicated shape, specified for fxn Ex: Skull/Vertebrae

Short Bones

Flat Bone = Sternum

Irregular Bones

Bone Structure Epiphysis : rounded end of a long bone Diaphysis : long midsection of a long bone Haversian Canal : series of tubes that surround blood vessels and nerves in compact bone *Bone Structure Info

Haversian Canals

Histology-Bone Slide

Axial Skeleton: consists of head and trunk, total of 80 bones Appendicular Skeleton: used for locomotion and manipulation of objects, 126 bones

Pelvic Girdle

Pelvis with Ligaments

Skull/Cranium

Bones and Age Cells in the bones will continually break down and create new bone as we age and our bodies change. “Remodeling” of bones is meant to resist fractures as we age, but also can lead to osteoporosis over time with poor nutrition Video TERMS o Osteoclast o Osteoblast o Osteocyte