Bone Flashcards
what are the functions of bone?
Support, Locomotion, Protection, Haematopoiesis, Mineral storage, Acid-base balance, Detoxification
what are the sections of bone?
Epiphysis= ends of long bones. Diaphysis= shaft of long bones. Metaphysis= between the other two articular cartilage at ends periosteum covering outside
what is spongy bone composed of?
trabeculae which branch and intersect
what surrounds bone?
a layer of dense connective tissue, the periosteum
what are the bone forming cells?
osteoblasts
where are osteoblasts found?
the periosteum and the endosteum which possess osteogenic potency
what is a haversian system?
lamellae and central canals
what is found between lacunae?
canaliculi
does spongy bone contain haversian systems?
no
what does the yellow marrow in spongy bone consist of?
adipose tissue
what is osteoporosis?
A disease characterized by low bone mass and micro architectural deterioration of bone tissue, leading to enhanced bone fragility and an increase In fracture risk
what are osteoblasts?
immature bone cells that synthesize osteoid and mediate mineralisation
what do osteocytes release?
calcium for homeostasis
what controls osteocyte activity?
calcium levels, parathyroid and calcitonin
what are osteocytes?
inactive osteoblasts
what is an osteoclast?
a large phagocytic cell with many mitochondria and lysozymes which break down bone matrix
what stimulates osteoclasts?
parathyroid hormone
what inhibits osteoclasts?
calcitonin
what are the processes of osteogenesis?
- intramembranous ossification
2. endochondral ossification
what is intramembranous ossification?
replacement of connective tissue sheets with bone tissue ie Flat bones
what is endochondral ossification?
replacement of a hyaline cartilage model with bone tissue ie Long bones
