Bones, joints, cartilages, and ligaments

When we were born we had over 300 bones. As we grew up, some of the bones fused together. As an adult we only have ____ bones! 97% of all the creatures do not have a backbone or spine.The human hand has 27 bones and our face has 14! The smallest bone in our body is the stirrup bone in our ear it measures 1/10 of an inch. 206

Video

1.Support 2.Protection 3.Movement 4.Storage 5.Blood cell formation 6.Homeostatic balance

Our bones are an internal framework Without bones to hold us up, we’d all be gooey piles of mush flopping around on the floor Bones are the ‘reinforced concrete’ of the body

Bones protect soft body organs For example, what would happen to our brain if we didn’t have a skull?? Our vertebrae protect our spinal cord Can you think of any other examples?

Skeletal muscles are attached to bones by tendons These muscles use our bones as levers to move the body and its parts

Fat is stored in the internal cavities of bones Bones are a ‘storehouse’ for minerals, including calcium and phosphorous IMPORTANT: Ca2+ (calcium ion) must be present in the blood at all times for 1.the nervous system to transmit messages 2.for muscles to contract 3.for blood to clot

“Hematopoiesis” is blood cell formation Hematopoiesis occurs within the marrow cavities of certain bones

Longer than they are wide They typically have a long centerpiece with a head at both ends All the bones of the limbs (legs, arms) except the carpals and tarsals

Generally cube shaped Contain mostly spongy bone Best known example is a patella Carpals, tarsals

Thin, flattened Usually curved Have two thin layers of compact bone sandwiching a layer of spongy bone Most bones of the skull, the ribs, and the sternum

Any bone that doesn’t fit into a previous category Vertebrae of the spinal column, hip bones

HINT: Humans have 7. 7 !! Both Humans and giraffes have the same amount of bones on their necks, just that the giraffes have a much longer vertebra.

Compact and spongy

Compact Spongy

COMPACT Dense Looks smooth and homogenous SPONGY Composed of small needlelike pieces of bone and lots of open space

Yucky! General anatomy of our bones

Pg 133

Diaphysis: the shaft of a long bone, filled with compact bone Epiphysis: Rounded end of a long bone Distal epiphysis Proximal epiphysis

Periosteum: Fibrous connective tissue that covers and protects the diaphysis The periosteum contains the blood vessels and nerves that provide nourishment and sensation to the bone.

Instead of periosteum, articular cartilage covers both epiphyses Glassy hyaline cartilage which makes it smooth and slippery Why do you think our bones are covered with glassy hyaline cartilage?

The epiphyseal line is a remnant of the epiphyseal plate (a flat line of hyaline cartilage) seen in young, growing bone When the bones are done growing, the epiphyseal plate is completely replaced by bone

In adults, the cavity of the diaphysis is primarily a storage area for FAT (or ‘adipose’ tissue) This is called yellow marrow. The cavity where the yellow marrow is found is called the medullary cavity.

Short bones!

206!

1.What are the different functions of bones? Name as many of the six as you can. 2.What are the four types of bones? 3.What are the ends of a long bone called? The proximal and distal ____________? 4.What is the inner cavity of the diaphysis called? 5.Watch this video and reflect: “What properties of the skeletal system make this man’s talent possible?” A Man With No Bones