Bone Growth Factors & Damage/Repair Flashcards
factors regulating bone growth
activity level, hormones, nutrition
activity level makes renewed bone
denser and stronger
peak bone mass
skeleton has grown to maximum size
hormones related to bone growth
growth hormone, calcitonin, estrogen, testosterone
growth hormone
stimulates liver to produce IGF (insulin growth factor)
growth hormone is released by
pituitary gland
IGF role
causes cartilage proliferation in children, decreases adipose tissue, stimulates bone growth, increase in muscle mass in adults
calcitonin
pulls calcium from blood to stimulate bone growth
calcitonin is produced by
thyroid gland
estrogen and testosterone
stimulates osteoblast activity for accelerated speed of bone tissue growth
estrogen and testosterone is produced by
gonads and adrenal gland
why are females more suceptible to bone loss?
smaller bones/muscles to start with, menopause stops estrogen production (cannot stimulate osteoblast activity)
nutrition
required for normal bone growth and maintenance
important nutrition vitamins
vitamin A, C, D
vitamin A
responsible for activating osteoblasts
vitamin C
responsible for collagen synthesis (protein component of bone)
vitamin D
stimulates calcium and phosphate absorption; important for calcification of bone
osteoporosis
space between trabeculae gets larger; bones become porous
what causes osteoporosis?
osteoclast activity is faster than osteoblast activity causing bone to become porous due to dissolving activities
fracture
damage or crack in a bone
types of fractures (cause)
stress, traumatic, pathological fracture
stress fracture
thin break caused by recent physical activity
traumatic fracture
impact/stress
pathological fracture
occurs in bone weakened by disease
types of fracture (soft tissue damage)
closed/simple, open compound
closed/simple fracture
internal
open compound fracture
breaks the skin
what part of the bone contain pain receptors?
periosteum, endosteum
repair of a fracture
- bleeding occurs due to damaged blood vessels and blood clot forms and help to hold things in place
- callus develops to unite inner edges and stabilize outer edges
- bone CT replaces cartilage CT
- remodeling, external callus would be cleared by osteoclasts, and little evidence of fracture will remain (swelling on bone initially marks location of fracture
