Skeletal System Flashcards
(37 cards)
What are the basic components of the skeletal system
Ligament (connects bone to bone)
Bone
Skeletal muscle
Cartilage
Tendon (connects muscle to bone)
What is the axial skeleton?
Bones in skull, vertebral column and thoracic cage
What is the appendicular skeleton?
Bones of the thoracic and pelvic limbs
What are the types of bones in the skeletal system and examples of each?
Irregular bone (vertebrae)
Pneumatic bone (paranasal sinuses)
Flat bone (scapula)
Short bone (carpal bones)
Sesamoid bone- these are small bones embedded in the tendon (patella)
Long bone (femur)
Splanchnic bone (baculum)
What are fibrous joints?
Bones connected by fibrosis tissue
No joint cavity
Three types:
1. Suture which is immovable
2. Syndesmosis which is slightly movable
3. Gomphosis which is immovable
What are cartilaginous joints?
Bones connected by cartilage
No joint cavity
Two types:
1. Synchondrosis which is immovable
2. Symphisis which is slightly movable
What are synovial joints?
Freely movable
Cavities between bones are filled with synovial fluid
6 types:
1. Ball and socket (spheroid joint)- allows the greatest range of movement
2. Plane (gliding joint)- allows only gliding movement
3. Pivot (trochoid joint)- allows movement limited to rotation
4. Condylar (condyloid, ellipsoid, or ellipsoidal joint)- allows angular motions but not rotation
5. Hinge (ginglymus)- movement is limited to flexion and extension
6. Saddle (sellaris joint)- allows all movement except rotation
What is the simple bone structure?
Epiphysis
Metaphysis
Diaphysis (shaft)
Metaphysis
Epiphysis
What are the structures of a long bone?
Red marrow
Spongy bone
Epiphyseal line
Compact bone
Medullary cavity
Periosteum
Endosteum
Yellow marrow
Nutrient arteries
Nutrient foramen
Articular cartilage
What are the structures of other bones that are not long bones?
Periosteum
Red marrow
Compact bone
What is compact bone also known as?
Cortical bone
What is spongy bone and what is it also known as?
Also known as Cancellous bone or Trabecular bone
It is a meshwork of supporting bundles of supporting fibres called trabeculae
How is blood supplied in bones?
Nutrient artery and vein
Periosteal blood vessels- covers the entire length of the bone shaft
Metaphyseal-epiphyseal blood vessels- supply blood to the ends of long bones
What is the matrix of a bone?
Contains collagen fibres (organic component) and calcium salts (inorganic component)
Hydroxyapatite crystals account for approx 60% of the weight of bones
Collagen fibres account for approx 30% of the weight of bones
Water content is approx 8%
What is the bone composed of?
Matrix
Several types of cells that all differentiated from the same basic cell
What are osteoprogenitor cells?
Mesenchymal cells that divide to produce daughter cells that differentiate into osteoblasts. They maintain the population of osteoblasts
They are found in the periosteum and endosteum
What are osteoblasts?
They line the surface bone, and make the organic components of the bones matrix. When they are completely surrounded by bine matrix they become osteocytes
What are osteocytes?
Matured bone cells located in the bone matrix that make up more of the cell population. Mechanosensors- stimulate bone formation in the presence of mechanical stimuli, or degradation in the absence of such stimuli
What are bone lining cells?
Former osteoblasts and cover bone that is not remodelling. Regulate the movement of calcium and phosphate into and out of bone
What are osteoclasts?
Bone-resorbing cell. Derived from the same stem cells which produced monocytes and macrophages. Form by the fusion of many cells (50 or more nuclei). Important role in the regulation of calcium and phosphate levels in body fluids
Where are blood cells produced?
Produced in the red marrow
What are the functions of the skeletal system?
Support- bones and cartilage peonies the scaffold that supports the body
Movement- contraction of the skeletal muscles move bones, producing body movements
Protection- bone is rigid and protects the organs it surrounds. The skull protects the brain, the vertebrae shields the spinal cord, and the rib cage protects the heart, lungs and other organs of the thorax
Storage- bone acts as a reservoir for minerals important to the body, such as calcium and potassium. Adipose tissue is stored in the yellow marrow and can serve as a source of energy for other tissues
Blood cell production- bone is major site for haematopoiesis. Red blood cells, white blood cells, and platelets are all produced in red marrow
What are the main stages of bone formation?
Mesenchymal cells
Hyaline cartilage
Primary ossification centre + bone collar
Spongy bone formation + blood vessel penetration
Secondary ossification centre + medullary cavity formation
articular cartilage
Endochondral bone development
What does bone growth and development depend on?
Balance between bone formation and bone resorption
Osteoclasts are constantly removing bone matrix and osteoblasts are always adding to it. Their actions are balanced
