Skeletal System Unit 4

Skeletal System Functions Protection* Support* Movement Calcium Store 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 Incus Malleus 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 Unfused at birth (“soft spots”), allows for some movement

Bone Marrow Location and Donation Bone marrow donation is one of two methods of collecting blood forming cells for bone marrow transplants. Bone marrow donation is a surgical procedure that takes place in a hospital operating room. Doctors use needles to withdraw liquid marrow (where the body’s blood-forming cells are made) from both sides of the back of your pelvic bone. You will be given anesthesia and feel no pain during the donation. After donation, your liquid marrow is transported to the patient’s location for transplant.

Sutures Infant to Adult The skeleton of a newborn infant contains around 300 separate parts. All bones start out as cartilage and turn into bone through a process known as ossification. This process is usually still underway at birth, so an infant skeleton is composed of both bone and cartilage

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,Skull

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 Periosteum is a tough fibrous membrane that surrounds the outside of bones  Compact Bone is the firmer outer layer of bone tissue, contains calcium matrix Spongy Bone is softer, more porous inner bone tissue  Compact Vs. Spongy

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

Skull/Cranium Parietal Bone Frontal Bone Zygomatic Bone Occipital Bone Maxilla Temporal Bone Mandible

Skull Sutures

Pelvic Girdle Iliac Crest Hip Joint

Pelvis with Ligaments

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 Osteoclast Osteoblast Osteocyte