Bones Flashcards
Name 5 reasons why your skeleton is important
Movement
Protection (of internal organs)
Support (shape)
Storage
Blood cell production
How many bones are in the human body?
206
What bones does the axial skeleton contain?
Bones of head, neck, back and chest
(it is the vertical central axis of the body)
How many bones does the axial skeleton contain?
80
What is the role of the axial skeleton?
Protects the brain, spinal cord, heart and lungs
What bones does the appendicular skeleton contain?
Bone of upper and lower limbs and the pelvic girdle.
How many bones does the appendicular skeleton contain?
126
What is the role of the appendicular skeleton?
Designed for movement and stability
Name the 5 types of bones and give an example of each one
Long = femur
Short = carpal
Flat = frontal
Sesamoid = patella
Irregular = vertebrae
What are the similarities between tendons and ligaments?
Located around joints.
Made of collagen.
What are the differences between tendons and ligaments?
Tendons bind muscle to muscle and transfer force.
Ligaments connect bone to bone and stabilise structure.
Name 5 anatomical landmarks of long bones
Diaphysis
Ephiysis
Epiphysial line
Medullary cavity
Understeer
Describe the diaphysis
Shaft of the bone
Composed of cortical bone
Allows the bone to withstand high forces without bending or breaking
Describe the epiphysis
Expanded ends of long bone
Composed of trabecula bone
Describe the epiphysial line
It is formed when the the growth of bone has stopped
Describe the medullary cavity
Inside the bone
Contains bone marrow
Red blood cells are produced
Describe the understeer
Less well-defined layer of connective tissue
Found in the inner wall of bone cavities
What do bones contain?
Inorganic material (65%)
Organic material (10%)
Magnesium, sodium and bicarbonate (25%)
What does the inorganic material in bones do?
Responsible for hardening the tissue (calcification)
What does the organic material in bones do?
Provide flexibility to the bone and tensile strength
What happens if there is no collagen in the bone?
It becomes brittle
What happens if there is no minerals in the bone?
It becomes flexible
What are the paradoxical properties of bones?
- lift weight to allow movement
- hard and strong to resist external force
- stiff to provide rigidity for leverage
- flexible to absorb energy
Name the 2 materials bones can be made from
Cortical
Trabecular
Give a physical description of cortical bones
Smooth and solid
Cylinder shape
Dense protective shell
Designed for strength
Give a physical description of trabecular bones
Light, porous, spongy and mesh like
Rigid lattice designed to make bones lighter
Used for strength
Name the fundamental unit (1st level structure) of cortical bones
Osteons
Name the fundamental unit (1st level structure) of trabecular bones
Trabeculae
Give the % of skeletal muscle of each bone material type
Cortical = 80%
Trabecular = 20%
Describe the location of cortical bones
Around all bones
Beneath the periosteum
In shafts of long bonds
99:5 radial diaphysis cortical: trabecula
Describe the location of trabecular bones
Vertebrae
Flat bones
End of long bones
Vertebra 25:75 cortical: trabecular
Name the 3 types of bone cells
Osteoblasts
Osteocytes
Osteoclasts
Name the function and location of osteoblasts
Function: bone formation, help synthesis and secrete collagen which is needed to build new bone tissue
Location: growing portions of the bone (including the periosteum and endosteum)
Name the function and location of osteocytes
Function: maintain mineral concentration of matrix, maintain daily cellular activities of bone tissue, sense mechanical strain.
Location: entrapped in the matrix
Name the function and location of osteoclasts
Function: bone reabsorption
Location: bone surfaces and at the site of old, injured or unneeded bones
What are osteogenic cells?
Unspecialised stem cells which undergo cell division
Describe what coupled bone remodelling is
Takes place in normal bones.
Bone resorption = bone formation
No change in bone mineral density
Equal activity of osteoblast and osteoclasts
Describe what uncoupled bone remodelling is
Takes place in osteoporosis
Bone resorption > bone formation
Lose of bone mineral density resulting in thinner, brittle bones
What is ossification?
The process by which bones form
What is interstitial growth?
Bone growth in length
Occurs in the epiphyseal plate
What is appositional growth?
Bone growth in width
What is the metaphysis?
The region where the epiphysis joins the diaphysis
What does Wolff’s Law state?
‘Bone adapts to loads under which it is placed’
Structure and shape of bone can be altered over time in response to loading.
Explain what happens during bone formation
Response to increased stress
Osteoblasts dominate
Bone becomes stronger
Explain what happens during bone resorption
Response to decreased stress
Osteoclasts dominate
Bone becomes weaker
What does ‘mechanostat’ state (Harold Frost)
Bones adapt with an aim to keep bone strain consistent and at an optimal level by altering bones structure
Name common diseases of the skeletal system
- arthritis: osteoarthritis, rheumatoid arthritis
- bone diseases: rickets, osteoporosis, osteopenia
- common skeletal injury in sport: stress fracture
What happens when astronauts leave earth?
Their bones experience a gradual loss in bone density (1-2% per month)
What can occur when athletes over train microfractures?
Stress fractures
