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5 main functions of skeletal system
- 1) Support- framework for attachment of soft tissue
- 2) storage- Stores lipids and Minerals
- 3) Blood cell production- contained in Red Marrow
- 4) Protection- Soft tissue and organs surround by bones
- 5) leverage
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Bones divided into 6 Groups
- 1) Long bones
- 2) short bones
- 3) Flat bones
- 4) Irregular
- 5) sesamiod bones
- 6) Sutural bones
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long bones example
Humerous/ Femer
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Short bones example
Carpals
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flat bones example
Sternum
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Irregular Bones example
Vertebrae/ Pelvic
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Sesamoid bones example
(find out)
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Sutural bones example
Sutures
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5 main parts of long bones
- 1) Diaphysis
- 2) Epiphysis
- 3) Metaphysis
- 4) Marrow Cavity
- 5) Cortex
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2 types of Marrow and their function
- 1)Yellow- Aids in storage of lipids and other minerals
- 2) Red- Areas of blood cell protection
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Canaliculi
Small passages for exchanging nutrients gases and wastes
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Osseos Tissue 4 types of cells
- 1)Osteocytes
- 2)osteoblasts
- 3)osteoprogenitor cells
- 4)Osteoclasts
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Osteocytes 2 major functions
- 1) Recycle Ca Salts
- 2) Help repair damage bone
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Osteoblasts functions
Produce new bone matrix (osteogensis)
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Osteoprogenitor cells functions
- Aid in the repair of fractures
- Produce Osteoblasts
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Osteon
The basic unit of compact bone- Consisting of osteocytes organized around a central canal and separated by concentric lamellae
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Osteoclasts functions
Secrete acids to release the stored energy
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Periostem
Fibrous outer layer of bone that helps to isolate bone from surroundings
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Endostem
- Lines marrow cavities
- Made of a simple layer of osteopragenitor cells
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Intermembranous Ossification 3 steps
- 1) Messenchymal cells secrete organic part of the matrix, this becomes mineralized with Ca salts
- 2) Bone grows out and forms struts called spicules
- 3) Finally forms spongy bone, but can later become compact bone
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Endochondral Ossification 6 steps
- 1) Cartilage grows, chondrocytes enlarge (cartilage cells), Lancunae expand and the Matrix is reduced, chondrocytes are deprived of nutrients and die
- 2) Blood vessels from- help to from the periostemand and an inner osteogenitc layer
- 3) Blood supply increases to the periosteum and begins to calcify the cartilage
- 4) Bone enlarges, osteoclasts appear and erode away a central marrow cavity
- 5) Capillaries and osteoblasts migrate to the epiphysis to form secondary ossification centers
- 6) Epiphysis filled with spongy bone with a thin layer of cartilage left (articular cartilage) that prevents damage at joints
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3 Major sets of blood vessels
- 1) Nutrient artery and Vein- enter through a foramen in the diaphysis
- 2) Metaplyseal vessels- Supply the inner surface of each epiphyseal plate
- 3) Periosteal vessels- From the periosteum
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Calcitrol
- Made in the kidneys
- Necessary for Ca absorption in the small intestines
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Vitamin C
Needed for Collagen synthesis
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Vitamin A/B12
- synthesis of bone protein
- Growth hormone
- Puberty stimulates sex hormones which cause osteoblasts to make bones quicker
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Calcium balance Decrease in Ca+2 levels
- Chemoreceptors of parathyroid release PTH (parathyriods Hormones)
- Leads to an osteoclast increase (Destroying Bone)
- Increase the rate of absorption of Ca Ions
- Decreases the rate of excretion of Ca +2 at the kidneys
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Calcium Balance Increase in Ca +2 levels
- Chemoreceptors of thyroid
- Releases Calcitonin (Inhibits activity, Calciton)
- With less Ca+ in fluids
- 1) inhibits intestinal absorption
- 2) increases Excretion in Kidneys
- 3) Increases osteoblast activity
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Repair steps
- 1) From a Hematoma (Large Blood clot)
- 2) External callus and an internal Callus if needed
- 3) Osteoblasts replace central cartilage
- 4) Osteoclasts and osteoblast remodel region for about 4 months to over a year
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Effects of Aging
- 1) Osteopenia- Inadequate ossification
- -Reduces bone mass
- 2)Osteoporosis- server reduction of bone mass
- -due to sex hormones different for male and women
- 3) Cancer in bones causes the production of osteoclast activity factor
- -Causes very sever bone reduction and osteoporosis
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Process
Any projection or bump
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Ramus
An extension of a bone making an angle with the rest of the structure
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Trochanter
A large, rough projection
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Tuberosity
a smaller, rough projection
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Tubercle
a small, rounded projection
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head
the expanded articular end of an epiphysis, separated from the shaft by the neck
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Neck
A narrow connection between the epiphysis and he diaphysis
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Condyle
A smooth, rounded articular process
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Trochlea
A smooth, grooved articular process shaped like a pulley
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Facet
A small, flat articular surface
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Fossa
A shallow depression
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Foramen
A rounded passageway for blood vessels or nerves
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Canal
A passageway through the substance of a bone
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fissure
An elongate cleft
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Sinus or antrum
A chamber within a bone, normally filled with air
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