Skeletal System

What are the functions of the skeletal system?

Provides physical support, protection, movement, mineral storage (calcium)

What are the types of tissue in the skeletal system

Bone - cells in a solid matrix; cartilage - cells in a semisolid matrix

What are the types of cartilage?

Hyaline cartilage, fibrocartilage, elastic cartilage

What is hyaline cartilage made of? And define it

• Chondrocytes,

• Lacuna,

• Semisolid extracellular matrix,

• Perichondrium,

• Avascular;

Most common type, strong but flexible

What is the perichondrium?

Dense irregular connective tissues; has blood vessels to nourish cartilage

Define fibrocartilage (what is in it and where is it located?)

• Chondrocytes,

• Lacuna,

• ECM (with lots of collage fibers),

• NO perchondrium;

located in intervertebral disks, menisci of the knee, pubic symphasis

Define elastic cartilage

• Chondrocytes,

• Lacunae,

• ECM (lots of elastic fibers),

• Perichondrium;

Located in epiglottis and ear

In what ways does cartilage grow

Appositional growth and interstitial growth

Define appositional growth

Growth from the outside, done by chondroblast (located in the perichondrium)

What does a chondroblast do?

Make more ECM and trap themselves inside a lacuna

What is the difference between chondroblasts and Chondrocytes

Chondroblast - are not in a lacuna;

Chondrocytes are in a lacuna

Define interstitial growth

Growth from the inside, chondrocytes divide and make new lacunae and ECM

What are the types of bone tissue?

Spongy bone - made of trabeculae;

Compact bone - made of osteons

What is the anatomy of an osteon (from top to bottom)

• Central Canal,

• Artery,

• Vein,

• Nerve,

• Lymph vessel,

• Endosteum,

• Concentric lamellae - rings of rigid ECM, store and create tricalcium phosphate and calcium carbonate,

• Collagen fibers - provide tensile strength to the bone,

• Osteocytes - make the ECM,

• Lacunae - protect osteocytes from ECM,

• Canaliculi - share oxygen and nutrients with cells; allow cells to communicate (in bones)

What aids the Communication of Osteons

Concentric, interstitial, and circumforential lamellae;

Perforating canals - allows blood vessels to travel

Periosteum

Define the periosteum

Outermost layer of the bone (outside surface)

What are trabeculae?

Store red bone marrow (where new blood cells are formed)

What is hematopoiesis?

The formation of new blood cells

What makes up spongy bone?

• Lamallae,

• Osteocytes in lacunae,

• Canaliculi,

• Endosteum,

• Osteoblasts,

• Osteoclasts

What is the difference between osteoblasts and osteoclasts?

Osteoblasts lay down the ECM;

Osteoclasts destroy ECM

What is the anatomy of a long bone?

• Epiphysis,

• Diaphysis,

• Compact bone - makes bones strong,

• Spongy bone - stores red marrow,

• Epiphyseal plate (growth plate hyaline cartilage),

• Epiphyseal line - where we stop growing (compact bone),

• Medullary cavity - yellow marrow, adipose tissue (stores fat),

• Periosteum- lines everywhere that does not articulate with another bone (rough surface),

• Articular cartilage - hyaline cartilage, reduces friction (smooth surface)