Chapter 6 A&P Flashcards
What are the 3 general functions of bone?
- Support/Protection
- Hemopoiesis
- Storage of calcium mineral
What is Hemopoiesis?
Production of blood cells occurring in red bone marrow
What does bone store?
Calcium Mineral
Describe the diaphysis.
Elongated, usually cylindrical shaft
What is the knobby region at the ends of a long bone called?
Epiphysis
End of the bone CLOSEST to the trunk?
Proximal epiphysis
End of the bone FARTHEST from the trunk?
Hint: Think of distance.
Distal epiphysis
What is articular cartilage covered by? Why?
A thin layer of hyaline cartilage for reducing friction and absorbing shock
What is the region called of mature bone between diaphysis and epiphysis?
Metaphysis
What cavity is in the middle of the bone?
Medullary cavity
What is found in adults to indicate they are done growing?
The epiphyseal line
What provides for continued bone growth (lengthwise)?
Epiphyseal plate
What is Endosteum?
Hint: Endo = in
Tissue that covers all internal surfaces of bone within medullary cavity
What is Periosteum?
Hint: Peri = around
Tough sheath of tissue covering the outer surface of the bone
What are the 2 types of bone marrow?
Red and yellow
Which bone marrow is made up of a fatty substance?
Yellow
What are the 4 kinds of cells in the bone?
- Osteoprogenitor- primordial
- Osteoblasts (baby bone cells)
- Osteocytes- maintenance
- Osteoclasts- eat bone, cause to release calcium
2 main divisions of bone tissue:
Compact and Spongey
What is the purpose of compact bone?
Provides protection and support
What is the purpose of spongey bone?
It provides tissue support
What is compact bone composed of?
Osteons
What lies at the center of osteon where blood vessels and nerves travel?
Central canal
What is the Concentric lamellae?
The rings of bone surrounding the central canal
What is a component of spongey bone?
Trabeculae
What is trabeculae?
Form of meshwork of crisscrossing bars to provide resistance to stresses
What is the process of bone formation called?
Ossification (osteogenesis)
When would bones form? (4 ways)
- Fetal development
- When bones grow before adulthood
- When bones remodel
- Fractures heal
What are the two forms in which ossification takes place?
Intramembranous and Endochondral
What kind of bones are formed with intramembranous ossification?
Facial bones
Steps of intramembranous ossification: (4)
- Form thickened regions
- Osteoid undergoes calcification
- Extracellular matrix develops into trabeculae to fuse to form spongey bone
- Development of periosteum from periphery of bone
True or false: The epiphyseal plate starts as cartilage.
True, it only solidifies into bone once you are done growing.
What is bone remodeling?
The continual process of bone deposition and resorption
How does one get increased bone mass?
Weight-bearing activities
How does decreased bone mass happen?
No to little stress on the bone structure which causes demineralization
What are the 4 steps of the healing process when a bone fractures?
- Reactive phase- formation of fracture hematoma
- Formation of fibrocartilaginous callus
- A bony callus formation
- Bone remodeling
What percentage of calcium do bones store?
99%
What is secreted when calcium levels drop?
Parathyroid hormone (PTH)
When calcium is released, what is then stimulated to increase bone breakdown?
Osteoclasts
What is Osteopenia?
When bone density and mass decrease, usually due to older age
What is the more severe version of Osteopenia?
Osteoporosis
