Bones Flashcards
What are the functions of the skeletal system?
- Support
- Enables movement
- Protection
- Blood cell production
- Stores and releases minerals and fats
What type of tissue does yellow bone marrow store?
Adipose tissue
Where does hematopoiesis (blood cell production) take place?
Red bone marrow
What are the two parts of long bones?
- Diaphysis
- Epiphysis
Define:
Diaphysis
- Tubular shaft between proximal and distal ends of bone
Define:
Medullary cavity
Hollow center of diaphysis, filled with yellow marrow
What are the walls of the diaphysis made of?
Compact bone
Define:
Epiphysis
Ends of proximal and distal bone
Where do the epiphysis and diaphysis meet?
At the metaphysis
Define:
Epiphyseal plate
Growth plate, contained in the metaphysis
Define:
Endosteum
Lining of inner surface of medullary cavity
Define:
Periosteum
Surrounds outer surface of bone
What are the three types of bone markings?
- Articulations
- Projections
- Hole
Define:
Articulation
Where two bone surfaces come together
Define:
Projection
Area of bone that projects above bone surface, where tendons and ligaments attach
Define:
Hole
Opening or groove that allows blood vessels and nerves to enter bone
Where does bone get its hardness and strength?
Hydroxyapatite crystals forming on collagen fibers
What are the four types of bone cells?
- Osteocyte
- Osteoblast
- Osteogenic cell
- Osteoclast
What is the function of osteoblasts?
Forms new bone
Where are osteoblasts found?
Periosteum and endosteum (growing portions of bone)
What is the function of osteocytes?
Maintain mineral concentration of bone matrix
How do osteocytes communicate with each other?
Long cytoplasmic processes that extend through canaliculi, channels within bone matrix
Define:
Osteogenic cells
Undifferentiated bone cells with high mitotic activity
What is the function of osteoclasts?
Breakdown of bone
Where is cortical/compact bone found?
Under periosteum and in diaphysis
What is the function of compact bone?
Provides support and protection
Define:
Osteon
Structural unit of cortical bone
Define:
Lamellae
Concentric rings of calcified matrix, makes up osteon
Define:
Haversian/central canal
- Contains blood vessels, nerves, and lymphatic vessels
- runs down center of each osteon
Define:
Perforating/Volkmann’s canals
- Extends to periosteum and endosteum
- location where vessels and nerves branch off at right angles
Where are osteocytes located?
Lacunae
Define:
Trabeculae
Lattice-like network of matrix spikes that contain lacunae and osteocytes
Where do arteries enter in the bone?
Via the nutrient foramen
What are the two osteogenic pathways?
- Intramembranous ossification
- Endochondral ossification
What are the types of bones formed by intramembranous ossification?
- Flat facial bones
- Most cranial bones
- Clavicles
What type of bones are formed via endochondral ossification?
Bones at base of skull and long bones
Why does endochondral ossification take longer than intramembranous ossification?
Cartilage serves as a template to be entirely replaced by new bone.
Define:
Primary ossification center
Region deep in periosteal collar where ossification begins
Define:
Secondary ossification center
New center of activity within the epiphyseal regions where matrix mineralization, chondrocyte death, cell cell invasion from periosteum, and osteogenic cells becoming osteoblasts occurs
Where does longitudinal bone growth occur?
In the epiphyseal plate
What are the two sides of the epiphyseal plate?
- Epiphyseal side
- Diaphyseal side
Which side of the epiphyseal side does cartilage form?
Epiphyseal side
Which side of the epiphyseal plate is cartilage ossified?
Diaphyseal side
Define:
Appositional growth
Growth of bone diameter
Define:
Joint
Area where adjacent bone(s) and cartilage come together
What are the three types of functional joints?
- Synarthrosis
- Amphiarthrosis
- Diarthrosis
What are the three types of structural joints?
- Fibrous joint
- Cartilaginous joint
- Synovial joint
Define:
Synarthrosis
Immobile joint
Define:
Amphiarthrosis
Slightly moveable joint
Define:
Diarthrosis
Freely moveable joint
What are most cartilaginous joints functionally classified as?
- Synarthrosis
- Amphiarthrosis
What are all synovial joints functionally classified as?
Diarthrosis
What are some examples of synarthrosis joints?
- Sutures
- Manubriosternal joint
What are some examples of amphiarthrosis joints?
- Intervertebral disc
- Pubic symphysis in pelvis
Diarthroses can be classified as:
- Uniaxial
- Biaxial
- Multiaxial
Define:
Fibrous joint
Adjacent bones united by fibrous connective tissue
Define:
Cartilaginous joint
Bones joined by hyaline cartilage or fibrocartilage
Define:
Synovial joint
Articulating surfaces not directly connected but come into contact via joint cavity filled with synovial fluid
What are the three types of fibrous joints?
- Suture
- Syndesmosis
- Gomphosis
What are the two types of cartilaginous joints?
- Synchondrosis
- Symphysis
Define:
Bursa
Thin connective tissue sac filled with fluid to prevent friction between skin, muscle, or tendon with underlying bone
What are the six types of synovial joints?
- Pivot
- Hinge
- Saddle
- Plane
- Condyloid
- Ball-and-socket
