Bones and the Skeletal System

Advanced Biology 2013

• Bones• Cartilage• Ligaments

Bones

• Osseous Tissue (Connective tissue)

Types of Bones• Long Bones

– Longer than they are wide– Produce body movements

• Short Bones– Equal in length and width– Limited motion (Gliding)

• Flat Bones– Enclose and protect soft organs– Provide area for muscle attachment

• Irregular Bones– Vertebrae, Sphenoid, Ethmoid

Long Bones

• Compact Bone (dense) – surrounds the medullary cavity which contains the bone marrow

• Spongy Bone (cancellous)- loosely organized form of bone tissue– Diaphysis-Shaft, provides leverage– Epiphysis-Expanded head, strengthens the joints

• Articular Cartilage-Where one bone meets another, Hyaline cartilage

Fig. 30-4

Cartilage

Spongy bone(contains redbone marrow)

Cartilage

Spongybone

Compactbone

CentralcavityYellowbone marrow

Bloodvessels

Fibrousconnectivetissue

Flat Bones

• 2 layers of compact bone which encloses a middle layer of spongy bone (dipole)

Bone Cells

• Osteogenic Cells- Bone producing cells• Osteoblasts-Bone forming cells• Osteocytes-Former osteoblasts-help pass

nutrients and chemical signals to each other• Osteoclasts-Bone dissolving cells, on bone

surface

Bone Marrow

• Red Marrow- Childhood, produces blood cells– In adults, Red marrow is only present in vertebrae,

ribs, sternum, and proximal heads of humerus and femur

• Yellow-Young-middle aged adults, fatty and no longer producing blood cells

• Gelatinous-Old age

SkeletonFig. 30-3a

Skull

ClavicleScapula

Shouldergirdle

SternumRibsHumerusVertebraRadiusUlnaPelvic girdleCarpals

PhalangesMetacarpals

Femur

Patella

Tibia

Fibula

TarsalsMetatarsalsPhalanges

Fig. 30-3b

Intervertebraldiscs

Hipbone

7 cervicalvertebrae

12 thoracicvertebrae

5 lumbarvertebrae

SacrumCoccyx

Fractures

Healing of Fractures

• 1. Hematoma Formation-Clot• 2. Formation of granulation tissue• 3. Callus formation (4-6 weeks)• 4. Remodeling (3 months)

Joints

• Fibrous Joints- Sutures• Cartilaginous Joints- Vertebrae• Bony Joints- Mandible/frontal bone• Synovial Joints

– Ball and socket, Hinge, Saddle, Pivot, Gliding, and Condyloid