Module 2 | BONES

What are the functions of bones?

support, protection, movement, mineral storage, blood cell formation, energy storage

What is the perichondrium? What does it act as?

-dense irregular connective tissue that surrounds cartilage

-Like a girdle to resist outward expansion when the cartilage is subjected to pressure

How many bones do we have?

206 bones

What is hyaline cartilage?

most abundant type of cartilage, each chondrocyte occupies a cavity called lacunae (little lake), only type of fiber in matrix is collagen, forms networks too thin to be seen w/ microscope

What is the function of hyaline cartilage?

provides support through flexibility and resilience

What is elastic cartilage? function?

-elastic fibers along with delicate collagen fibrils

-very elastic and able to tolerate repeated bending

What is fibrocartilage? function?

-Contains rows of thick collagen fibers, alternating rows of chondrocytes, each surrounded by cartilage matrix

-Resist both strong compression and strong tension forces

What is appositional growth?

appositional growth = growth from outside (width)
Chondroblast in perichondrium produce new cartilage tissue by actively secreting matrix

What is interstitial growth?

interstitial growth = grown from inside (length)
Chondrocytes inside cartilage divide and secrete new matrix
Expanding cartilage from within

What is it called when bones make contact?

Joints and articulations is the location at which two or more bones make contact.

What is axial skeleton?

bones that lie around the body's center of gravity

What is appendicular skeleton?

bones of the limbs, or appendages

What is compact bone?

dense outer layer; look smooth and homogenous

What is spongy bone?

(trabeculae) internal network of bone, composed of small bars of bone, open spaces filled with bone marrow

What is the epiphyseal plate?

a disc of hyaline cartilage that grows during childhood to lengthen the bone

Once the bone stops growing what happens?

when long bone stops growing these areas are replaced with bone and appears as thin barely discernible remnants (epiphyseal lines)

What is the nutrient foramen?

the opening into the canal which gives passage to the blood vessels of the medullary cavity of the bone

What is an osteon?

group of concentric tubes resembling rings of tree, long cylindrical structures run parallel to the long axis of the bone and to the main compression stresses

What is the diaphysis?

It is the shaft of a bone composed of compact bone

What is each concentric ring (tube) called?

lamella

What is an osteocyte?

mature spider shaped bone cells that are essential for maintaining bone matrix

What are the organic components of bone?

35% of bone tissue mass
cells, fibers, ground substance
contributes to flexibility, tensile strength
resists stretching and twisting

What are the inorganic components of bone?

65% of bone tissue mass
hydroxyapatites (mineral salt) primarily calcium phosphate
resists compressing, provides bone with exceptional hardness

What type of cartilage does bone replace in embryo?
When does it happen?

bone replaces hyaline cartilage at week 8

What is osteogenisis (ossification)?

process of bone tissue formation
a)formation of bony skeleton in embryos
b)bone growth until early adulthood
c)bone thickness, remodeling & repair in adults