Ch. 6 Bones And Skeletal Tissues Flashcards
Bone nourishment
Blood vessel -> Perforating canal -> Central canal -> Canaliculi. -> Osteocyte.
Practice question
why does a surgeon order an X-Ray in a hand if a girl will have jaw surgery.
Hard to see if the patient is still growing so they need an accessible area to x-Ray and the hands is the easiest.
Epiphysis epiphyseal line and plate
Composition of bones
Bones
Joints with cartlidge, tendons, and ligaments
Cartilages
Hyaline cartlidge: provides firm support with some flexibility
- Articular cartlidges cover the ends of bones at movable joints
- Costal cartlidges connect ribs to the sternum (breastbone)
- Respiratory test, voice box and nasal areas.
Elastic cartlidge:stretch flexibility, external ear and epiglottis (and flap covering larynx
Fibrocartlidge: Strength from collagen fibers but cushioning ability also found at sites subjected to heavy pressure and stretch (pubic symphysis). Pad like cartlidges of the knee (menisci). The discs between vertebrae (intervertebral discs)
Functions of Bones
Support Protection Movement Mineral storage Triglyceride (fat) storage Blood formation
Classification of Bones: by shape not size
Long bones:elongated with shaft + two ends (finger, femurs)
Short bones: roughly cube shaped (ankle and wrist bones)
Flat bones: sternum, scapulae, ribs, most skull bones
Irregular bones: vertebrae, hip bones
Types of Bone Tissue
Compact: smooth and solid appearance
Spongy: Honeycomb, sponge like.
Gross Anatomy of Bones (naked eye)
Bone Markings
Structure of a typical Long Bone
Structure of short, irregular bones, and flat bones
Gross anatomy of Bone Markings
Projections (bulges): heads, trochanter psych, spines, etc.
Depressions and openings: Fossa, sinuses, foramina, grooves
Gross anatomy of Structure of a typical long bone
Diaphysis (shaft): forms longitudinal axis, medullary cavity filled with yellow marrow.
Epiphysis: (expanded end area): Epiphyseal line and plate.Red marrow produces red blood cells. Articular cartlidge.
Blood vessels: high vascularized
Membranes:
Periosteum (outside):outer double layered membrane
-Sharpey’s (perforating) fibers secures periosteum to underlying bone. More concentrated (dense) at tendon and ligament attachment.
Endiosteum (inside): delicate, internal C.T. Membrane that lines all internal passageways.
Gross anatomy of the structure of short, irregular and flat bones
Stuffed sandwich with thin plates of periosteum-covered compact bone on the outside and endosteum- covered spongy bone within
Not cylindrical, so no shaft or epiphyses.
Contains bone marrow between trabeculae but no marrow cavity.
Microscopic anatomy of bone
Bone consists of extracellular matrix secreted by bone cells
Bone cells are entrapped within the matrix; responsible for maintains and remodeling.
Bones cells called:
Osteoblasts
Osteocytes
Osteoclasts
Osteoblasts
Makes bones
Bone forming cells, build up matrix called ossification or osteogenesis
Synthesize collagen
Accumulate calcium and phosphate
Appositional growth: osteoblasts of the inner periosteum add a new layer to the preexisting bone
Osteocytes
Mature bone cells that function to maintain the existing matrix. Osteoblasts trapped in the new matrix now called osteocytes.
Osteoclasts
Bone destroying cells
Responsible for the breakdown and reabsorption of bone matrix
Secrete H+ acid and enzymes to breakdown mineralized bone matrix
Calcium and phosphorus are freed
