The Skeletal system Flashcards
What are the organic components of osseous tissue matrices?
Water (25%), extracellular fibres (25%), inorganic salts (50%)
Where does bone get it’s durability?
The deposition of calcium salts in the matrix
How many bones does an adult human contain?
206
What are the main functions of bone?
Protection
Movement
Support
Bone marrow
Storage
What are the 5 classifications of bone shape?
Short, long, flat, irregular, sesamoid
What are long bones specially used for?
Lever action in conjunction with muscles
What are short bones specially used for?
Areas where limited movement is required
What are flat bones especially used for?
Protection of soft tissues and providing large attachment sites for muscles
What are sesamoid bones especially for?
Areas where there is considerable tension or stress, they protect tendons from excessive wear and tear
What is component X?
Diaphysis
What are the components X?
Metaphysis
What are components X?
Epiphysis (Proximal/distal)
What are components X?
Articular cartilage
What is component A?
Spongy/cancellous bone
What is component B?
Epiphyseal line (Growth plate)
What is component C?
Red bone marrow
What is component D?
Endosteum
What is component E?
Compact/cortical bone
What is yellow bone marrow mostly made of?
Fat
What does red bone marrow produce?
Red blood cells
How does the epiphyseal plate change with growth?
It starts as a layer of hyaline cartilage which allows the bone to grow in length. After adulthood when growth stops this layer is changed to bone
What is the periosteum and it’s functions?
A layer covering the outside of the bone that isolates the bone from surrounding tissues and plays a role in the growth and repair of bones
What is the endosteum?
The inner surface of bone
When is the endosteum active?
During growth of the bone
What is the diaphysis?
The long tubular mid section of long bones
What is the medullary cavity?
The hollow centre of the bone containing yellow bone marrow
What are epiphyses?
The expanded ends of long bone
What is the metaphysis?
An area in a mature long bone where the epiphysis joins the diaphysis
What does the periosteum consist of?
An outer fibrous layer and an inner osteogenic layer
What forms the outer layer of all bones?
Compact/cortical bone
What gives compact/cortical bone its definitive hardness and strength?
It has a strong calcified bony matrix, filled with organic ground substance leaving only tiny spaces inbetween.
Theses small spaces contain the osteocytes and are connected to each other by tiny channels called canaliculi.
What are the tiny gaps in compact bone that contain osteocytes?
Lacunae
What percentage of the human skeleton is compact/cortical bone?
80%
How is compact/cortical bone structured?
Many cylindrical units called osteons surrounded by interstitial lamallae and outer circumferential lamallae
What is the structure of an osteon?
Concentric layers called lamellae around a longitudinal central (Haversian) canal containing blood vessels, nerves and lymphatic vessels. Perforating (Volkmann’s) canals branch off of the central canal at right angles spreading vessels and nerves outward and inward
What is the structure of spongy/cancellous bone?
Lamellae arranged in needle-like threads of bones called trabeculae which contain osteocytes in lacunae. The spaces in between these trabeculae are filled with bone marrow.
What is the upper arm bone?
Humerus
What are the lower arm bones?
Ulna and radius
What is the thicker of the lower arm bones?
Radius
What bones form the heel of your hand?
Carpals
What bones form the palms of the hands?
Metacarpals
What bones form the fingers?
Phalanges
What is the upper leg bone?
Femur
What is the knee capbone called?
Patella
What are the lower leg bones?
Tibia and fibia
What is the larger of the lower leg bones?
Tibia
What is the shoulder blade bone called?
Scapula
What is the collar bone called?
Clavicle
What is the ankle bone called?
Talus
What is the heel bone?
Calcaneus
What bones form the midfoot and hind foot?
Metatarsals and tarsals
What bones form the forefoot?
Metatarsals and phalanges
What are the two divisions of the skeleton?
Axial skeleton and appendicular skeleton
What does the axial skeleton consist of?
The head and trunk of the body including the skull, hyoid bone, chest and spine
What are the main bones of the skull?
Frontal
Nasal
Zygomatic
Maxilla
Mandible
Sphenoid
Parietal
Temporal
Occupital
What are the 5 sections of the spine and how many vertebrae are in each?
Cervical (7)
Thoracic (12)
Lumbar (5)
Sacral (5)
Coccyx (Fused section)
What is the function of bone marrow?
Red bone marrow helps produce blood cells (RBC, leukocytes and platelets).
Yellow bone marrow helps store fat. (Yellow bone marrow also contains mesenchymal stem cells. These are cells that can develop into bone, fat, cartilage, or muscle cells.)
Do adult bones contain mostly red or yellow bone marrow, why?
Most bones in an adult body contain yellow bone marrow because yellow bone marrow starts to replace red bone marrow over time.
Which two minerals make up the majority of bone structure?
Calcium carbonates
Calcium phosphates
What is ossification?
Bone formation
What is the basic process of intramembranous ossification?
Mesodermal cells are transformed into osteoblasts which secrete osteoid which becomes calcified
What is the basic process of endochondral ossification?
Mesodermal cells differentiate into cartilage cells, the bones are initially formed from this
What is the ‘Growth plate’?
During ossification there is actively growing cartilage between the shaft of a long bone & the epiphysis this is called the epiphyseal plate or ‘growth plate’.
For how long into life are bones developing?
Bones continue to grow in length and thickness into adolescence.
What is non-traumatic bone remodelling and what is required for it?
Bones constantly repairing themselves. - Under normal daily stresses bones develop micro fractures and are repaired.
Vit D, calcium, phosphate, parathyroid hormone & various steroid hormones are required for this to continue.
