HOSA Veterinary Science: Skeletal System

Remodeling

construction of new bone tissue and breaking down of old bone tissue

Fetal Skeleton

Fully developed at the end of 3 months

Five Functions of The Skeletal System

Framework

Protection

Levers

Production of Red Blood Cells

Storage

Structural Framework

Supports

Soft tissues

Provides points of attachments for

Tendons

Skeletal muscles

Protection

Protect vital organs from injury

Example skull protects the brain, ribs protect the heart and lungs

Levers

Muscles attach to bones to help provide movement

Mineral Homeostasis

Storage and release of minerals

Stores calcium and phosphorus which contribute to bone's strength

99% calcium supply is stored in the skeleton

Releases minerals in the blood on demand to maintain mineral homeostasis

Diaphysis

Bones shaft

Long cylindrical shaft

Main portion of bone

Metaphyses

Contain epiphyseal plate in growing bones (Growth plate)

A layer of hyaline cartilage that allows the diaphysis to grow in length

Closed Epiphyseal Plate

Bones ceases to grow in length

18 - 21

Epiphyseal plate is replaced by bone

Articular Cartilage

Thin layer of hyaline cartilage

Covering parts of the epiphysis

Forms articulation (joint) with another bone

Purpose

Reduce friction

Absorb shock at freely movable joint

Periosteum

Surrounds external bone surface wherever it is not covered by articular cartilage

Function of Periosteum

Enable the bone to grow in thickness but not length

Protects bone

Assist in fracture repair

Helps nourish bone tissue

Serves as an attachment for ligaments and tendons

Medullary Canal

Hollow, cylindrical space within the diaphysis that contains yellow marrow

Yellow Marrow

Mainly fat cells

Found in central cavities of long bones

Endosteum

Thin membrane that lines the medullary canal

keeps the yellow marrow intact

Endo

within

Epiphyses

Proximal and distal ends of bone

Osteoblast

Bone building cells

Osteocytes

Mature bone cells

Osteoclast

Break down of bone matrix and reabsorbed

Compact bone

Contains very few spaces

Strongest form of bone tissue

Found beneath the periosteum and makes up the bulk of the diaphysis

Spongy Bone

Makes up bone tissue in the interior bone

Nutrient Foramen

Hole in the center of diaphysis

Nutrient artery passes

Epiphyseal Plate

Layer of hyaline cartilage in the metaphysis of growing bone

Scapula

Located on Dorsal thorax

Large flat triangular bone

Spine - raised ridge

Supraspinous fossa

Infraspinous fossa

Two Processes

Acromion

Coracoid

Glenoid fossa

Point of attachment for several muscles