Skeletal

Name the six primary functions of the skeletal system

Support, Protection, Movement, Mineral Storage, Site of Blood Cell Production, and Energy Storage

List the Components of Compact Bone

Few Spaces

What is the external portion of all bone

Compact Bone

What does the shaft of long bone do and what is it consisted of

Consisted of Compact bone—offers protection and support

Nutrients arteries through canals

What is the difference between Haversian and Volkmann’s Canals?

Haversian canals are found in the center of the bone and provide nutrition and support to the bone cells, while Volkmann’s canals are found at the edges of the bone and connect the Haversian canals to the bone’s surface.

What is around the Haversian Canal

Lamellae

What is the periosteum

Membrane on the surface of the bone

What does spongy bone usually not contain?

Osteons

What is the latticework of bones known as?

Trabeculae (also contain osteocytes and lacunae)

Spaces within the trabeculae contain what?

Red Bone Marrow

Location of spongy tissue

Short, flat, irregular bones, epiphyses

The central medullary cavity contains what?

Bone marrow

What does marrow contain

Two types of stem cells

Produces what prior to birth

Hematopoietic stem cells (HSC)

How many blood cells produced daily

Several million

Components of Red Marrow and Yellow Marrow

Red- contains all blood cells, platelets form

Yellow- 30 % lymphocytes—mature in lymph tissues—may revert to red if blood deficiency

What is Osteoperosis

Bone decay

Name the four types of bones

Long, short, flat, irregular (also sutural and sessamoid)

What is the diaphysis of the long bone

The shaft

What are the epiphyses of long bone

Ends of bone

What are the metaphyses

Where the epiphyses and diaphyses meet

What is articular cartilage and what does it do?

Hyaline cartilage at the end of epiphysis that connects to another bone, helps with friction.

Describe the outer layer of the periosteum

Contains blood vessels and nerves, not covered by cartilage

Describe the inner layer of the periosteum

Elastic fibers, cells (necessary for growth and repair)

What is the medullary cavity

Cavity within diaphysis; contains yellow bone marrow

What is the Endosteum

Medullary Cavity—contains osteoprogenitor cells which will become osteoblasts

Describe short bones and give an example

Cube shaped, equal in length and width, spongy w surface of compact bone, e.g wrists and ankles

Describe Flat bones and give an example

Thin-composed of two parallel plates of compact bone that encloses spongy

Protects

I.e- cranial, sternum, ribs

Deals with red marrow

Describe Irregular bones and give an example

Vary in shape, amount of spongy

Vertebrae, hip, some facial bones

Describe Sutural bones

Small bones between joints of some cranial bones—number varies person to person

Describe sesamoid bones

Small bones in tendons where pressure develops. Number varies by individual. E.g-patellae, kneecaps.

What are osteoprogenitor cells

Cells that produce osteoblasts through mitosis

What are osteoblasts

Form bone, collagen maintenance, repair

What are osteoclasts

Develop from white blood cells. Secrete digestive enzymes to break down bone

What does the matrix consist of

Consists of salts (calcium phosphate, calcium carbonate)

What are the two types of bone formation

Intramembranous, endochondral

Describe intramembranous growth and the four steps of

Originate in sheet-like layers in CT—usu. Flat bone

  1. Cells in mesenchyme form into osteoprogenitor cells
  2. When osteoblasts and vessels surrounded by calcified matrix, trabeculae results ( trabeculae bind together to form spongy, etc)
  3. Osteoblasts become trapped lacunae. Form osteocytes
  4. CT become periosteum

Describe Endochondral growth and the five steps of

  1. Cartilage decomposes
  2. Periosteum forms from CT around developing structure
  3. Cells form spongy bone where cartilage once was.
  4. Osteoblasts form compact around spongy
  5. Band of cartilage remains between epiphyses

What is remodeling

Only bone tissue replaced by new bone tissue

What are hematomas

Blood pocket around break

What is homeostasis maintained between

Osteoclasts (extracting calcium) and osteoblasts (produce calcium)

What do bones serve as

Calcium storage for body

What is responsible ofr destruction of bone tissue by how

Osteoclasts by removing calcium from bone when needed