bones Flashcards
characteristics of bones
- low cellularity
- EM is majority volume
- EM of soft connective tissue is 70-75% water
how much of collagen is dry mass
60-70%
what are types of skeletal articular structures
ligaments
tendons
menisci
bones
ligaments
tether bones across joints + controls relative motion of joints (limits ROM)
tendons
connects bone to muscle + transmits muscular forces to bone
- vascular, can adapt to exercise
what happens to tendons if there is low blood suppluy
adaptations will occur slower
what is the structure of the tendon
tendon –> fasicle –> fibrils + tendon cells –> subfibril –> microcollagen –> tropocollagen
what does tropocollagen work together with and what is the function
tropocollagen works with crosslinks which are compressive filament layers that help support tendon during tension
menisci
- maintain joint components in appropriate position, enhances rotation in synovial joints
- reduces joint stress
bones
- provide mechanical support
- dynamic tissue that can fluctuate bone mineral density
what is the ultimate determinator of ROM
ligaments
what is the largest calcium resevoir in the body
bones
what can cause tissue turnover in bones
injury, excessive mechanical resistance = damaged matrix = repair and building of new matrix
characteristics of fibrous connective tissue
- limited vascularity = slow to adapt
- restricted metabolic capacity during matrix turnover
- less vigorous adaptive response to stimuli than in bone
what type of cells are seen in fibrous connective tissue
fibroblasts: primary cells in tendons and ligaments repair/growth
fibrochondrocytes: primary cell of menisci
how does resistance training change bones
it can help stimulate bone repair and growth
- e.g. femoral neck gets bigger and the vertebrae get bigger
what kind of movements help with the most repair/growth in tendons and ligaments
whole body movements
how often do bones completely turnover
as little as 3 yrs, but normally every 7-10 yrs
what are the types of cells in bones
osteoblasts: increase BMD (must need some sort of mechanical strain in order to function)
osteocytes: maintain bone mineral density where located
osteoclasts: decrease BMD constantly active
what type of bone cell is mainly lost with age
osteoblasts (esp in women bc of osteoperosis)
when does bone modeling occurs
throughout childhood growthwh
when does bone remodeling occur
during different activities/movements
- only parts of the bone remodel based on microfracture that occur whereas modeling is the whole bone itself
what are factors that effect bone tissue remodeling
- current BMD
- bone strenght
what affects someones current BMD
- genetics (about 80%)
- environmental conditions (@ sea level people have bigger bones bc it grows faster where higher altitudes grows slower that’s why people are short)
