Bone Development Unit 3, lesson 3. Bone Development OSTEOGENESIS (a.k.a. ossification) is the...
Embed Size (px)
Transcript of Bone Development Unit 3, lesson 3. Bone Development OSTEOGENESIS (a.k.a. ossification) is the...
Bone DevelopmentUnit 3, lesson 3
Bone DevelopmentOsteogenesis (a.k.a. ossification) is the process of bone tissue formation.In embryos this leads to the formation of the bony skeleton.In children and young adults, ossification occurs as part of bone growth.In adults, it occurs as part of bone remodeling and bone repair.
Formation of the Bony SkeletonBefore week 8, the human embryonic skeleton is made of fibrous membranes and hyaline cartilage.After week 8, bone tissue begins to replace the fibrous membranes and hyaline cartilage.The replacement of fibrous membranes with bone is called INTRAMEMBRANOUS OSSIFICATION. The replacement of hyaline cartilage with bone is known as ENDOCHONDRAL OSSIFICATION
Growth in Bone LengthEpiphyseal cartilage of the epiphyseal plate divides to create more cartilageDiaphyseal cartilage of the epiphyseal plate is transformed into bone. This increases the length of the shaft.And you grow!!
As a result osteoblasts begin producing bone faster than the rate of epiphyseal cartilage expansion. Thus the bone grows while the epiphyseal plate gets narrower and narrower and ultimately disappears. A remnant (epiphyseal plate) is visible on X-rays (do you see them in the adjacent femur, tibia, and fibula?)At puberty, growth in bone length is increased dramatically by the combined activities of growth hormone, thyroid hormone, and the sex hormones.
Also called the spine, backbone, or spinal columnFunctions to:Protect the spinal cordSupport the headServe as a point of attachment for the ribs, pelvic girdle, and musclesThe vertebral column is curved to varying degrees in different locationsCurves increase the column strengthHelp maintain balance in the upright positionAbsorb shocks during walking, and help protect the vertebrae from fractureVERTEBRAL COLUMN
Composed of a series of bones called vertebrae (Adult=26)7 cervical are in the neck (small)12 thoracic are posterior to the chest cavity (medium)5 lumbar support the lower back (large)1 sacrum consists of five fused sacral vertebrae1 coccyx consists of four fused coccygeal vertebrae
SPINE CONDITIONSVarious conditions may exaggerate the normal curves of the vertebral column
Scoliosis lateral imbalance of the spine (bent left or right)Kyphosis arch in the upper spine (ky = high)Lordosis arch in the lower spine (lor = low)
Found between the bodies of vertebraeFunctions to:Form strong jointsPermit various movements of the vertebral columnAbsorb vertical shockINTERVERTEBRAL DISCS
Cervical RegionCervical vertebrae (C1C7)The atlas (C1) is the first cervical vertebraThe axis (C2) is the second cervical vertebraThoracic RegionThoracic vertebrae (T1T12)Articulate with the ribsLumbar RegionLumbar vertebrae (L1L5)Provide for the attachment of the large back musclesSacrumThe sacrum is a triangular bone formed by the union of five sacral vertebrae (S1S5)Serves as a strong foundation for the pelvisCoccyxThe coccyx, like the sacrum, is triangular in shapeIt is formed by the fusion of usually four coccygeal vertebraeThis is the tail boneVertebral Column (Regions)
So what is back pain?
Seriouslywhat is back pain?