Module 7: Skeletal System Flashcards
Name the functions of the Skeletal System (P.B.E.A.M.S)
- Protection
- Blood Formation
- Electrolyte Balance
- Acid-Base Balance
- Movement
- Support
To balance electrolytes, bone store and release ___ & ____ ions
Calcium & Potassium Ions
To balance Acid-Bases bone buffers blood or maintains neutral pH by what means?
absorbing or releasing phosphate or carbonate salts
Bone matrix is composed of
1/3 organic & 2/3 inorganic
organic matrix is made of
collagen
inorganic matrix is made of
hydroxyapatite
hydroxyapatite - Structure & Fxn
crystallized salt made up of calcium & phosphate; provides strength to tissue
If bone did not have organic matrix this would cause bone to be
very brittle & fragile; Hydroxyapatite crystals would fracture
If bone did not have Hydroxyapatite this would cause bone to be
rubbery & have no strength
Name 4 types of Bone cells
Osteogenic Cells
Osteoblasts
Osteocytes
Osteoclasts
Osteogenic Cells: fxn & location
stem cells found in endosteum & inner layer of periosteum
Osteoblasts
- derived from osteogenic cells
- nonmitotic (cannot reproduce themselves)
- bone forming
- produce organic bone tissue
______ remove calcium from bloodstream to build bone matrix, which lowers blood calcium levels
Osteoblasts
Osteocytes
- mature osteoblasts
- maintains homeostasis of bone material
Osteoclasts
- arise from fusion of 4 stem cells
- found on bone surface, has ruffled borders which increase surface area
- release hydrochloric acid returning calcium & phosphate into blood
- increasing calcium levels
Bone is formed by two types of tissue
Spongy & Compact Bone
Compact Bone
for weight bearing; formed by combining osteon
Osteon’s central & perforating canals contain
blood vessels & nerves
Lacunae
on edges of lamellae; tiny cavities contain osteocytes
Canaliculi
slender channels & allow osteocytes to communicate with one another
Spongy Bone
lattice of rods, spines & projections of bone
Osteons include … Name structures
Central Canal, Perforating Canal, Lamellae, Lacunae
Spicules
Spike & projections that stick out into cavity of spongy bone
Trabeculae: Structure & Features
form thin, plate-like structure; contain lamellae, no central canal
Spaces between Trabeculae are filled with____
Bone Marrow
____ ____ develops along lines of stress, disperses stress & pressure which allows for strength without weight
Spongy Bone
Long Bones
- longer than wide, work as levers
- used for movement, blood production & storage
- Ex(s) arms, legs, bones in hands & feet
Short Bones
- equal in length & width
- limited motion
- Ex(s) wrists & ankles
Flat Bones
- enclose, protects, and provides broad surface for muscle attachments
- Ex(s) cranial bones, ribs, sternum, scapula
Irregular Bones
vertebra of spinal column & sphenoid in cranium
Long Bone Anatomy: Epiphysis
ends of bone where they articulate, form joints with other bones
Long Bone Anatomy: Diaphysis
Shaft / middle of bone; forms walls of medullary cavity
Long Bone Anatomy: Medullary Cavity
aka Marrow cavity; contains bone marrow (red & yellow)
Long Bone Anatomy: Periosteum
- fibrous tissue covering/attaching to bone surface
- provides strength / anchors attaching muscles & tendons
- contains 2 layers:
outer layer made of thin collagen fibers
inner layer bone tissue forming cells
Long Bone Anatomy: Endosteum
thin layer of reticular connective tissue; lines medullary cavity
Long Bone Anatomy: Metaphysis Plate
aka Epiphyseal plate; connection between epiphysis & diaphysis
- made of hyaline cartilage in juveniles
Long Bone Anatomy: Articular Cartilage
- made of hyaline cartilage
- covers surface of epiphysis
- reduces friction to allow for smooth movement
Process of Ossification
bone growth; two types - Intramembranous & Endochondral
Intramembranous Ossification
produces flat bones; within membrane of mesenchyme
Endochondral Ossification
- produces long bones, ribs, vertebra, etc..
- develops from cartilage converted to osseous tissue
