Human Anatomy- Bones and Skeletal Tissues

Bones

provide support and shapeto body

serve as attachment sites for muscle

serves as a storage depsoit for essential minerals

site of blood cell formation

Cartilages

cushions abutting bone surfaces

joints

articulations between bones

Three types of cartilage

Hyaline cartilage

Elastic cartilage

Fibrocartilage

Where is cartilage generally found?

joints, ribcage, nose, ear, intervertebral discs

Cartilage tissue is made up of?

60% water, chondrocytes in lacunae within the extracellular matrix. It is resilient

Extracellular matrix

contains fibers and a gel-like ground substance. 35% organic components- primarily collagen 65% inorganic mineral salts, primarily calcium phosphate

Cartilage is surrounded by?

perichondrium

Hyaline cartilage

most abundant type, frosted glass appearance, thin collagen fibrils, high water content

Found un articulations of joints, costal cartilage, and in the respiratory system

Elastic cartilage

contains elastic fibers, tolerates repeated bending, found in the epiglottis and the external ear

Fibrocartilage

contains thick collagen fibrils, resists both compression and strong tension forces. Found at the intervertebral discs some ligaments, and in some articular joints

Cartilage growth

appositional growth-chondroblasts in perichondrium produce new tissue, interstitial growth-chondrocytes within divide and secrete new matrix. Growth is rapid in fetal development and childhood stops growing in late teens

Appositional growth

“growth from outside”

Interstitial growth

“growth from within”

Functions of Bone

Support, Movement, Protection, Mineral storage, Blood cell formationm, Energy storage, Energy metabolism- produces osteocalcin

Osteocalcin

increases insulin secretion, influences adipose cells to store less fat

What kind of tissue is bone?

connective tissue

Bone composition

Osteoprogenitor cells, Osteoblasts, Osteocytes, Osteoclasts

Osteoprogenitor cells

stem cells

Osteoblasts

actively produce and secrete bony matrix (osteoid)

Osteoclasts

derived from macrophages

Bone classifications

long, flat, short, irregular

Structure of a typical long bone

Proximal and distal epiphysis on ends, middle contains diaphysis. Epiphysis contains spongy bone

Clinical Connection: Intramedullary Nails

critical component in the management of longe bone fractures, offering a stable fixation method with minimal damage to surrounding tissues

Structure of a Flat Bone

Compact bone borders, spongy bone inside (made of trabeculae of spongy bone)

Tuberosity

large rounded projection; may be roughened