Skeletal System & Skeletal Joints

Function of the Skeletal System 1.Enables you to move. 2.It provides shape and support. 3.Protects your organs. 4.Produces blood cells. 5.Stores minerals and other materials until your body needs them.

Bones, Bones and More Bones

 The bone is surrounded by a tough layer of connective tissue called the periosteum (pehr-ee-AHS-tee-um).  Blood vessels that pass through the periosteum carry oxygen and nutrients to the bone.

What makes up a bone?  Beneath the bone’s outer membrane is a layer of compact bone, which is hard and dense, but not solid.  Small canals run through the compact bone. These canals carry blood vessels and nerves from the bone’s surface to the living cells within the bone.

What makes up a bone?  Just inside the compact bone is a layer of spongy bone. Like a sponge, spongy bone has many small spaces within it.  This structure makes spongy bone tissue lightweight but strong. Spongy bone is also found at the ends of the bone.

What makes up a bone?  The spaces in many bones contain a soft, connective tissue called marrow.  There are two types of marrow—red and yellow.

What makes up a bone?  Red bone marrow produces some of the body’s blood cells.  Some bones contain yellow marrow. This marrow stores fat that can serve as an energy reserve.

How do Bones Change  The skeleton of an embryo is composed almost entirely of a type of connective tissue called cartilage.

Development of Bones  Cartilage is replaced by bone during the process of bone formation called ossification.  Ossification begins to take place up to seven months before birth.

Bone Growth…  A baby is born with a temporary skeleton of mostly soft cartilage.  They have a total of about 350 bones.  Bones gradually harden as a child grows. The calcium phosphate needed comes from milk.  Bones grow outward from the center.

 BrainPOP | Health | Learn about Skeleton BrainPOP | Health | Learn about Skeleton BrainPOP | Health | Learn about Skeleton

Skeletal System  Types of Skeletal Joints

Types of Joints  A place where one bone attaches to another bone is called a Skeletal Joint

Types of Skeletal Joints  Immoveable Joints include the cranium and the pelvic girdle.  Immoveable joints are bones that are fused together and will never move

Ball and Socket Joint ● Allow the greatest range of motion ● Allow the greatest range of motion ●The hips and shoulders contain ball-and-socket joints ●The hips and shoulders contain ball-and-socket joints ● This allows you to swing your arms and legs in a circle

Moveable Joints Hinge Joint  Like a hinge on a door, a hinge joint allows extensive forward and backward motion  Elbows, knees and fingers also have these types of joints. fingers

Hinge Joints

Pivot Joint  Allows only rotary movement  The pivot joint in the top of your neck gives you limited ability to turn your head from side to side

Pivot Joints

Gliding Joint  Allows one bone to slide over another  Examples can be found on your wrist and your ankles.

Gliding Joint

Which Joints are being used? Do the following activities with me: –MOVE YOUR ARM IN A CIRCLE –PUSH OPEN A DOOR –LIFT A BOOK FROM A DESK –KNEEL DOWN –WAVE YOUR HAND –TWIST YOUR HEAD FROM SIDE TO SIDE

How do the bones Stay together?  Ligaments : The function of ligaments is to connect bone to bone. Ligaments provide stability in the joints by preventing too much movement.  Tendons: The function of tendons is to connect muscle to bone. Tendons carry the force from the muscle that moves the bone  Cartilage: Cartilage is used to cushion the junction of two bones.

Skeletal System Disorders  Excessive strain on a joint may produce inflammation, a response in which excess fluid causes swelling, pain, heat, and redness. Inflammation of a bursa is called bursitis.  A more serious disorder is arthritis, which involves inflammation of the joint itself. Arthritis affects approximately 10 percent of the world's population.

Skeletal System Disorders  In older people, especially women, loss of calcium can lead to a weakening of the bones, a condition known as osteoporosis.  Osteoporosis can cause many serious fractures.  BrainPOP | Health | Learn about Joints BrainPOP | Health | Learn about Joints BrainPOP | Health | Learn about Joints