Osteology (lecture 3) Flashcards
What is part of the skeletal system?
- Bones
- Cartilages
- Joints
What is the study of bones?
Osteology
What is the study of joint?
Arthrology
What are the 4 classes of bones?
Long (e.g. humerus)
Short (e.g. carpal)
Flat (skull/face)
Irregular (e.g. scapula)
What is a living skeleton (e.g. humans)
Endoskeleton
What is a non-living skeleton (e.g. insects)
Exoskeleton
What is a sesamoid bone?
Floating (does not form a joint)
What are the functions of bone?
- Support
- Protection
- Acts as a lever (w muscles) for mvmt
- Storage/Release area for minerals
- Blood cell formation (RBCs)
- Triglyceride storage (yellow bone marrow)
What are the two types of ossification?
1) Endochondral: Bone forms by replacement of hyaline cartilage (long bones of the extremities)
2) Intramembranous: Forms directly in the matrix by increasing growth of collagenous fibers (flat bones of the skull and face)
Describe bone tissue.
- Complex and dynamic living tissue
- Continually remodeling
- Several tissues working together: osseous, cartilage, dense connective tissue, epithelium, adipose, and nervous
Name and describe the 4 bone cells.
1) Osteoprogenitor cell (develops into osteoblast)
2) Osteoblast (forms bone extracellular matrix, always creating new bone cells)
3) Osteocyte (maintains bone tissue)
4) Osteoclast (destroy/remove tissue that needs to be replaced)
Name and describe the general features (parts) of the bone.
1) Diaphysis: shaft (on all long bones)
2) Epiphyses: distal/proximal ends of bone
3) Metaphyses: in btwn diaphysis & epiphyses
- Epiphyseal plate: part of metaphysis (growth plate)
4) Articular cartilage (hyaline)
5) Periosteum: outer layer of connective tissue, covering all except articular cartilage
6) Medullary cavity: storage, makes bones lighter
7) Endosteum: inner layer of connective tissue, lines medullary cavity
Describe compact bone.
- surface of bone, but can extend deeper
- makes up most of diaphysis of long bones
- looks dense (solid) but porour microscopically
- Protects/supports
- Resistant to stresses from weight/mvmt
Name all the parts of compact bone.
- Osteons (Haversian systems)
- Osteonic (Haversian) canals
- Concentric Lamella(e)
- Lacunae
- Canaliculi
- Interstitial lamellae
- Interosteonic (Volkmann) canals
- Circumferential lamellae
- Perforating (Sharpey’s) fibers
What is the periosteum and name the 2 layers.
Fibrous membrane (CT) surrounding complete bone except at articular cartilage.
1) Outer: fibrous
2) Inner: Osteogenic
Describe Spongy Bone Tissue.
(trabecular/cancellous bone)
- does not contain osteons
- interior of bone, protected by compact bone
Describe/name parts of Spongy Bone.
Trabeculae: lamellae arranged in irregular pattern of thin columns
- concentric lamellae
- osteocytes
- lacunae
- canaliculi
Spaces btwn trabeculae filled w red bone marrow at extremities (blood cell production) or yellow bone marrow (adipose tissue)
Where does bone tissue get its blood supply from?
1) Periosteal arteries
2) Nutrient artery
3) Metaphyseal arteries
4) Epiphyseal arteries
Describe the periosteal arteries.
- Enter diaphysis thru interosteonic canals
- supply periosteum + outer part of compact bone
Describe the nutrient artery.
- Enters near center of diaphysis via obliqued angled hole: nutrient foramen
- Path is away from dominant growth end of bone (go to elbow, flee knee)
Describe the metaphyseal arteries.
- Arise from arteries around associated joint
Describe the epiphyseal arteries
- Arise from arteries around associated joint
What are the 4 stages of bone formation?
1) Initial formation in embryo and fetus
2) General growth thru infancy, childhood, and early adulthood
3) Bone remodelling thru life
4) Repair (from fractures) thru life)
Explain the first stage of bone formation.
- Initially from mesenchyme (CT in embryo)
- Forms general shape of bone
- Then goes thru a type of ossification
