Components - Joints - Cartilage - Ligaments and Tendons - Bone

Cartilage – A connective tissue  Hyaline  Elastic  Fibrocartilage

Hyaline cartilage - 4 Types

Articular cartilage- covers ends of bones and moveable joints

Costal cartilage – attach ribs to the sternum

Respiratory cartilage - forms respiratory passages and larynx

Nasal cartilage - forms external nose

Elastic cartilage - Forms external ear - Forms epiglottis

Elastic cartilage

Fibrocartilage Withstands heavy pressure & tensile forces - Intervertebral disks - Knees and elbows

Fibrocartilage

Classification of bone  Long bones  Short bones  Sesamoid bones  Flat bones  Irregular bones

Sesamoid bones form within a tendon e.g. patella

“We are all sculptors and painters, and our material is our own flesh and blood and bones.” Henry David Thoreau

Achondroplasia abnormal bone growth that results in short stature with disproportionately short arms and legs, a large head

Diastrophic dysplasia is a disorder of cartilage and bone development.  This condition is inherited in an autosomal recessive pattern

Hormone Control of Bone Remodeling  PTH (Parathyroid hormone) is released by parathyroid glands when serum calcium levels are low which increase osteoclast activity.  Calcitonin is released by the thyroid gland when serum calcium levels are too high which stimulate osteoblast activity (causes them to release alkaline phosphatase)

Calcitonin PTH

Watch Breaking Bones

Homeostatic Imbalance Fracture – a break in the bone Open fracture – bone penetrates through the skin Closed fracture – bone does not penetrate skin

Homework  Explain in your own words, as if you were explaining to a middle school student, how a long bone grows. Include the effects of nutrition and hormones on development.

Depressed Fracture

Compression Fracture

Fracture treatment  Closed reduction – When a physician pulls on bone to realign bone ends  Open reduction – When a physician surgically inserts pins or wires to realign bones

Open Reduction - Mandible

Fracture healing 1. Hematoma formation 2. Fibrocartilaginous callus formation 3. Bony callus formation 4. Bone remodeling