skeletal system skeletal system. support and movement protection (brain, lungs) mineral storage of...

SKELETAL SYSTEM

Skeletal Skeletal SystemSystem

•Support and movement•Protection (brain, lungs)

•Mineral Storage of Calcium and Phosphate•Red Blood Cell Production (long bones)

•Fat (Energy) Storage

Functions of Skeletal SystemFunctions of Skeletal System

Amount of bones in the human body: 206

Smallest bone: stirrup (middle ear)

Largest bone: femur (thigh bone)

longest, strongest, and heaviest bone supports much of our body weight

Two Divisions:

Axial skeleton and Appendicular skeleton

SKELETAL SYSTEMSKELETAL SYSTEM

HUMAN SKELETONHUMAN SKELETON

Front View (Anterior) Back View (Posterior)

Skull: •Cranium•Facial bones

Sternum

Vertebral column (spine)

Ribs (Absent in frogs)

Sacrum

Axial SkeletonAxial Skeleton

Bones of the two girdles and their attached limbs

Pectoral Girdle (Clavicle and Scapula) Upper Limb = Humerus

Radius & Ulna, Carpals, Metacarpals & Phalanges

Pelvic Girdle (coxal bones) Lower Limb = Femur

Tibia & Fibula Tarsals, Metatarsals & Phalanges.

Appendicular Appendicular SkeletonSkeleton

tarsals

metatarsalsphalanges

Long Bone Long Bone Section TissuesSection TissuesEpiphyses - ends

Diaphysis - main shaft

Epiphyseal Plates Cartilage lines where growth occurs

Periosteum

Outer, tough membrane Attachment for tendons and ligaments

Endosteum Membrane lining the medullary/marrow cavity

Marrow Cavity Red Marrow - production of red blood cells (in spongy bone tissue) Yellow marrow - fat storage

Articular Cartilage Between articulating bones cushions and protects bones

Long Bone Long Bone Section TissuesSection Tissues

Structure of Long BoneStructure of Long Bone

Compact Bone: Dense outer shell

Osteon – (Haversian System) •cylindrical unit •rings of solid matrix with calcium and phosphate salts•contains bone cells (osteocytes) •central osteonic canal contains blood vessels

Histology of Histology of Bone OsteonBone Osteon

Osteocyte in Lacunae

Haversian (Osteonic) Canal with blood vessels

Canaliculi(Canals that Connect lacunae)

Histology of CartilageHistology of Cartilage

Matrix

Chondrocytes in lacunae

The Matrix is a composite of elastin and collagen

Cartilage is avascular – cells rely on diffusion through the matrix for nutrients

Bone to BoneBone to Bone• Bones connect to other bones at joints• Connective tissue holds bones together

– Ligaments for moveable joints– Cartilage for semi-movable joints (ribs)

Musculoskeletal SystemMusculoskeletal SystemThe skeleton and muscles function together as the musculoskeletal system

Skeletal muscle: •Attached to bones by tendons •Moves bones•Voluntary control