Chapter 6: Bone Tissue,, Flashcards
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What cells make bone?
Osteoblasts
What cells breakdown bone?
Osteoclasts
What structure persists into adulthood and for life?
Articular cartilage
How do long bones lengthen?
By longitudinal growth
How does bone growth take place in long bones?
It takes place by pushing the epiphysis away from the diaphysis
What is bone growth in length called?
Longitudinal
What is bone growth in width called?
Appositional
How does the sun help bone growth?
Vitamin D comes from the sun, and increases osteoblast while decreasing osteoclast activity
What increases osteoclast activity?
Continuous pressure placed on bone, parathyroid hormone and decrease in calcium ion concentration
What decreases osteoblast activity?
Inaclequate exercise and dietary intake of calcium or vitamins c,d or K
What increases osteoblast activity?
Compressional load or exercise, testosterone, tension placed on bone and adequate dietary intake of vitamins c,d and k
What decreases osteoclast activity?
Estrogen, calcitonin, and increase in blood calcium ion concentration
Steps of bone repair?
1) hematoma fills ingap between bone fragments
2) fibroblast and chondroblasts go into hematoma and form soft callus
3) osteoblasts build bone ( hard ) callus
4) bone callus is remodelled and primary bone replaced with secondary bone
What cells contribute to calcification during inframembranous ossification?
Mesenchymal cells
Describe the epiphysis
The end of a diaphysis, covered with a thin layer of hyaline cartilage
What is the diaphysis
Shaft of the long bone
What is the articular cattilage?
A thin layer of hyaline cartilage that allows the bone to rub together with reduced friction at joints
What is the epiphyseal plate?
Growth plates that allow bones to grow in size
How de you know when a person is done growing?
The epiphyseal plate becomes a line
What are the 2 bone textures?
Spongy and compact
What does the compact bone do?
Allows bone to resist linear compression and twisting forces
What does the spongy bone do?
Allows long bones to resist forces from many directions
What are some things only long bones have?
Epiphyses,diaphyses, medullary cavities, ephyseal lines and plates
What are the functions of the skeletal system?
Protection blood cell formation, fat storage, movement and support
What are 5 bone shapes?
Long bones, short bones, flat, irregular and sesamoid
Example of each type of bone?
Long- humerus
Short - trapezium
Flat- sternum
Irregular- vertebrae
Sesamoid - patella
What are the types of bone marrow?
Red and yellow bone marrow
What kind of marrow decreases with age?
Red bone marrow
What is yellow bone marrow comprised of?
Triglycerides, blood vesselsand adipocytes
What are the kinds of fracture?
Simple and compound fractures
What steps are in the process of bone repair?
A hematoma fills the gap between bone fragments, fibroblasts and chondroblasts infiltrate the hematoma and a soft callus forms, osteoblasts build a bone callus, which is remodelled and the primary bone is replaced with the secondary bone
How is bone remodeling a negative feedback?
the body respond to a low calcium ion level
What kind of tendon is a sesamoid bone?
Specialized
What are some examples of flat bones?
Ribs, pelvis and most skull bones
What are some examples of trapezium bones?
Tarsals and carpals
What is the part of the bone that is outside and extends to the regular tissue and surrounds the long bone?
Periosteum
How many zones of hyaline cartilage are there?
5
What kind of cells are osteocytes?
Mature bone cells
What kind of cell deals with the process of bone deposition?
Osteoblasts
What kind of cell type deals with bone resorption/remodelling?
Osteoclasts
What is the lacuna?
Fluid filled cavity occupied by osteocytes
What are the structural units of mature compact bones?
Osteons
Why do skull bones develop faster than bones in other parts of the body?
They have intramembranous ossification, lacking a cartilage stage
What kind of ossification is seen in long bones?
Endochronal ossification
Why are women on average smaller than men?
They see plate closure sooner than men
What happens in terms of bone resorption and deposition when you are physically active?
Bone deposition is greater than resorption
What does PTH do?
Takes calcium out of the bone and into the bloodstream
Where is it most important to have calcium?
In the blood
What happens with there is a defect in the PTH?
Low blood calcium
What kind of fracture requires no surgery?
Simple
What kind of fracture usually occurs in kids?
Greenstick
