Bones Ch 6 - Ch 9 Flashcards
3 skeletal cartilage types
Hyaline
Elastic
Fibrocartilage
Hyaline
Most abundant, and made of fine collagen fibers.Support, flexibility and resistance.
Located: Articular, Coastal, respiratory and nasal cartilages.
Elastic Cartilage
Similar to hyaline but made up of flexible elastic fibers as well. Location: External ear and epiglottis.
Fibrocartilage
Highly compressible, made of chondrocytes alternating with collagen fibers.
Location: intervertebral discs, pubic symphysis and menisci
How does cartilage grow?
Appositional growth:from the out side.
Interstitial growth: from the inside.
4 bone types
Sutural Long Short Flat Irregular Sesamoid
Bone function
Support Storage of minerals and lipids Blood cell production Protection Leverage
2 most important minerals in bone
calcium and phosphate
Trabeculae
Honeycomb of small needle-like or flat pieces in spongy bone
diaphysis
Shaft that forms the long axis of the bone
Epiphysis
Bone ends, filled with spongy bone (no medullary space) and covered with compact bone.
Epiphyseal line
Divides the diaphysis and epiphysis and was the site of the growth plate in the youth (epiphyseal plate)
Bone membranes
Periosteum
Endosteum
Periosteum
White double layer membrane surrounding the bone, outside made of irregular CT, inside made of osreogenic stem cells
Endosteum
Delicate connective tissue layer that lines the inside of the bone. Contains osteogenic stem cells.
Nutrient foramen
Opening in the bone which the blood supply and nerves pass through
Sharpey’s fibers
Perforating fibers that anchor the periosteum to the bone and provide anchor points for ligaments and tendons.
Red marrow cavities
Found in spongy bone and is where hematopoiesis takes place–mostly in hip sternum,and heads of femur and humerus.
Bone markings
Projections, depressions and openings that serve as sights for muscle, tendon and ligament attachments.
Bone tissue cells
Osteogenic
Osteoblasts
Osteocyte
Osteoclast
Osteogenic cells
Mitotic stem cells, located in periosteum and endosteum.
Osteoblasts
Matrix synthesizing cell responsible for bone growth. Trigger the deposit of calcium salts in the organic matrix.
Osteocytes develop from osteoblasts.
Osteocyte
Mature bone cell that monitors and maintains the bone matrix-make up most of the cell population and occupy the lacuna.
Maintain protein and mineral content of the matrix
Involved in repair of damaged bones
Osteoclast
Bone reabsorbing cells. Use enzymes to break down bone and release stored minerals (osteolysis)
Large with 50+ nuclei
Derive from the cells that produce monocytes and macrophages, not from osteogenic stem cells
Components of compact bone
Osteon
Lamella
Canals & Canaliculi
Osteon
Tiny weight baring pillars, run parallel to the long across of the bone
Lamella
Each flat layer of the osteon, wrapped around the center like a tree trunk. Collagen fibers rin diagonally in opposite directions in each layer.
Canals
Central canals: Run through the core of each osteon
Perforating (Vilkmann’s) canals: Run from periosteum to medullary cavity.
Lamellae
Interstitial lamella: Incomplete lamella between osteons
Circumferential lamella: wrap around ostoens, under periosteum.
Hard matrix between cells
Bone composition
Organic: Bone cells and ground substances such as collagen
Inorganic: mineral salts, largely clacium phosphates.
2 types of bone formation
endochondal ossification:
Intermembranous ossification
7 stages of endochondal ossificstion
- Matrix starts to form as chondrocytes enlarge in the center
- Blood vessels grow around the edges of the cartilage and perichondrium cells convert to osteoblasts
- Blood vessels penetrate, fibroblasts migrate in and turn to osteoblasts, primary ossification center forms spongy bone.
- Remodeling creates a medullary cavity, length and diameter increase
- Capillarity and osteoblasts migrate into epiphyses and form secondary ossification center
- Epiphyseal plate forms and separates the diaphysis and epiphysis.
- Epiphyseal closure occurs at puberty
Intermembranous ossification
- Mesenchymal cells cluster together, differentiate into osteoblasts and begins to form bone matrix
- Ossification proceeds and some osteoblasts are trapped and differentiate into osteocytes.
- Blood vessels move in and accelerate growth, they become trapped in the matrix.
- Woven bone and periosteum forms with blood vessels throughout
- Osteons develop and surface tissue becomes periosteum.
Growth from epiphyeal plate
- Proliferation zone: Mitosis of cartilage cells
- Hypertrophic Zone: Older cartilage cells enlarge.
- Calcification; Matrix calcifies, cartilage cells die, matrix begins deteriorating & blood vessels invade.
- Ossification zone: new bone forms
Hormonal Controls for bone remodeling
Calcitonin: Calcium in to bone
Parathyroid hormone: Calcium out
Common types of fractures
Transverse: Break of a bone shaft across its long axis
Displaced/non-displaced: new abnormal bone arrangements/retain the normal alignment
Compression: Vertebrae subjected to extreme stress
Spiral: Produced by twisting stress that spreads along the length of the bone
Epiphyseal: Break that occurs where the cartilage is ossifying
Comminuted: Shatter affected area into a multitude of bony fragments
Greenstick: One side of the shaft is broken and the other is bent (common in children)
Colles: Distal portion of the radius, common in breaking a fall
Pott’s: Occurs in the ankle and affects multiple bones
4 Stages for healing a fracture
- Hemotoma forms
- Fibrocartilaginous callus forms
- Bony callus forms
- Bone remodeling occures
Canaliculi
Cracks that filaments run through in lamellae
Sutural bones
Also called Wormian bones
Small, flat, oddly shaped bones that are found between the flat bones of the skill.
Borders are like jigsaw puzzle pieces
Irregular bones
Complex shapes with short, flat, notched or ridged surfaces.
Vertebrae, the bones of the pelvis and some bones in the cranium
Short bones
Boxlike in appearance
Carpals and tarsals
Flat bones
Have thin parallel surfaces
Roof of the skill, sternum, and scapula.
Long bones
Relatively long and slender
Located in arm, forearm, thigh, soles, fingers and toes
Sesamoid bones
Usually small round and flat.
Develop inside tendons and are most often encountered near joints
Patella is an example that everyone has
Types of bone markings:
Elevations and projections
Openings
Depressions
Processes where tendons and ligaments attach
Processes where joints occur between adjacent bones
Elevations and projections (2)
Process: projection or bump
Ramus: Extension of a bone that forms an angle with the rest of the structure
Processes formed where tendons or ligaments attach (6)
Trochanter: Large rough projection Crest: Prominent ridge Spine: Pointed process Line: Low ridge Tubercle: Small rounded projection Tuberosity: rough projection
Depressions (2)
Sulcus: Narrow groove
Fossa: Shallow depression
Openings (5)
Sinus: Chamber with in a bone, normally filled with air
Foramen: Rounded passageway for blood vessels or nerves to pass
Fissure: Deep furrow, cleft or slit
Meatus: Passage or channel, especially the opening of a channel
Canal: Duct or channel
Processes formed where joints occur (5)
Head: Expanded articular end of an epiphysis
Neck: Narrow connection between epiphysis and diaphysis
Facet: Small flat articular surface
Condyle: Smooth rounded articular process
Trochlea: Smooth grooved articular process shaped like a pully
Spongy bone
Provides support and stores minerals
Mesh work of supporting trabeculae which are surrounded by bone marrow
Lighter than compact and can withstand stress from multiple directions
Red marrow
In the spongy bone in the epiphyses of long bones and in large bones such as the sternum and ilium.
Forms red blood cells
Yellow marrow
contains adipose tissue that is important as an energy reserve
Compact bone
Functions to protect, support and resist stress
Basic functional unit is the osteon which are arranged around a central canal.
Central canal
Also called the Harversian canal, contains one or more blood vessels.
Run parallel to the bones surface.
Perforating Canals
Also called Volksmann’s canals run perpendicular to the surface and supply blood to the deeper osteons and medullary cavity.
