Clinical Anatomy 1 Skeletal System Bones on Macroscopic feat Flashcards
What does the skeletal system consist of? (4)
- Bones
- Cartilages
- Joints
- Special forms of connective tissue
What are the 9 cells that are part of the skeletal system?
- osteoblasts
- osteoclasts
- osteocytes
- chondroblasts
- chondroclasts
- chondrocytes
- mesenchymal cells
- Monocytes (macrophage linage)
- Fibroblasts
What is Extracellular matrix (ECM)?
- Are the molecules/materials that surround the outside of the cell.
- Contains both organic and inorganic componts
- Makes the bulk of the tissues
What are 3 cartilage cells?
- chondroblasts
- chondroclasts
- chondrocytes
What are 3 bone cells?
- osteoblasts(needed when fracture occurs; bone-forming cells)
- osteoclasts (large cells that resorb or break
down bone matrix) - osteocytes(mature bone cells)
What is Mesenchymal cells? (3)
- Embryonic connective tissue
- Can differentiate into bone forming cells, cartilage forming cells, blood forming cells, and muscle forming cells.
- Known as the origin of most cells.
What are 2 organic components in ECM?
- Collagen fibers
2. Ground substance
What is collagen fibers in ECM? (3)
- Is the most abundant
- Principal fibrous component
- Confers tensile strength
What is ground substance in ECM?
There are two types: Bone & Cartilage
What is ground substance Bone in ECM? (7)
- Mineralized
- Inorganic components
- Calcium
- Phosphates
- Rigid and Strong
- Brittle
- Remodeling
What is ground substance Cartilage in ECM? (4)
- Not mineralized
- Firm, solid gel-like
- Stiff and incompressible
- More flexible and resilient than bone
What is cell modulation?
- Change reversible
- Ex: osteocytes can turn to osteoblasts if a bone fracture occurs
What are bones lined with? (2)
- Periosteum
2. Endosteum
What is Periosteum?
Lines the bone cavity
What are 5 functions of bone?
- Protection for vital structures
- Support for the body
- Mechanical basis for movement
- Storage for salts (CALCIUM and phosphates)
- Hematopoiesis (creation of new blood cells; in the bone marrow)
What are 2 bone classification based on location?
- Axial
2. Appendicular
What does the Axial skeleton consist of?
- Bones of the skull, vertebral column, and rib cage
- The clavicle and scapula are NOT part of the axial skeleton
What does the Appendicular skeleton consist of?
Bones of the upper and lower limbs, shoulder, and hip
What are the 6 shapes and sizes of bones?
- Long
- Small long bones
- Short
- Flat
- Irregular
- Sesamoid
What is Macroscopic structure?
- Also known as Basic Architecture
- Compact (cortical) bone
- Trabecular (cancellous, spongy) bone
What is Microscopic structure? (microscopic differentiation of the bone)
- Also known as Matrix arrangement
- Woven (fibrous/immature) bone tissue
- Lamellar (mature/secondary) bone tissue
What are 2 developmental origin in classification of bones? (2 ossification centre)
- Intramembranous
2. Endochondral
What are the 2 requirements for Long Bones?
- Bone marrow cavity
- Two epiphysis (one on each end)
*Are tubular shaped
What is epiphysis?
- Secondary ossification centers appear
- Most appear during childhood or adolescence
What is diaphysis (shaft)?
- Primary ossification centers
- Appears during the 7-20 weeks of intrauterine life
What is Metaphysis?
Growing part of diaphysis adjacent to epiphyseal plate
What is epiphyseal plate?
- A layer of hyaline cartilage
- Between epiphysis and Metaphysis
What are 2 requirements for small long bones?
- Epiphysis at one end
- No bone marrow cavity
*Ex: clavicle
What are short bones?
- Cuboidal in shape
- Ex: Carpus & Tarsus
What is flat bones?
- Are meant for PROTECTION
- Thin and flattened
- Ex: skull, ribs, shoulder girdle, and pelvic girdle
What are Irregular bones?
- Bones with complicated shapes
- Provide ATTACHMENT
- Ex: Vertebrae & Facial bones
What are sesamoid bones?
- Develop embedded in tendons closely related to articular surfaces
- PROTECT the tendons from excessive wear
- Like sesame seeds
- Ex: patella
What 3 bones develop from a single center of ossification?
- Carpal and Tarsal bones
- Auditory ossicles
- Facial bones
What are 2 classification of bones based on macroscopic structure?
- Compact (cortical/dense) bone
2. Trabecular (cancellous/spongy) bone
What is compact bone? (3)
- Also known as cortical or dense bone
- 85% of bones are compact bone
- Consist of Secondary Osteons (Haversian system)
What is Haversian system? (2)
- The structural unit
of compact bone - A cylindrical structure parallel to the long axis of the diaphysis
-Allow passage of blood vessels and nerves
Where is compact bone located? (4)
- Diaphysis of long bones
- Ends of long bones
- Internal and external surfaces of flat bones
- Surface of irregular and sesamoid bones
What is the function of compact bone? (3)
- Mechanical and protective function
- Provides strength for weight bearing
- Encloses Marrow (medullary) cavity that contains yellow marrow(reserve fat cells)
What is trabecular bone?
- Consist of bony trabeculae (spiculae)
- Projects out from internal surface of compact bone into bone marrow cavity.
- Composed of irregular lamellae that form anastomosing plates separated by intercommunicating spaces filled with red bone marrow
- DO NOT CONTAIN COMPLETE OSTEONS (Haversian system)
What is lamellae?
- Layers
- column-like matrix
tubes
Where are trabecular bones located?
- Inferior of flat bones
- At expanded ends (epiphyses) of the long bones
- Interior of Irregular and Sesamoid Bones
*Contains Red Marrow, which the function is Hematopoiesis
