Bone Tissue Flashcards
what is bone?
organ made up of several tissues (bone, cartilage, connective adipose and nervous tissues)
Functions of the Skeletal System
-Provides support
-Protects organs
-assists body movements
-mineral homeostasis
-blood cell production
-stores triglycerides
where are triglycerides stored in bone?
the adipose cells of yellow marrow
what are the structures of a long bone?
diaphysis
2 epiphyses
2 metaphyses
articular cartilage
periosteum
medullary cavity
endosteum
what is the diaphysis?
BONE SHAFT
what are the 2 epiphyses?
both ends of the bone at the joints
what are the 2 metaphyses
region between diaphysis and epiphysis
what does the articular cartilage cover?
both epiphyses
what is the periosteum?
connective tissue surrounding the diaphysis
what is the medullary cavity
Hollow space within diaphysis
what is the endosteum?
thin membrane lining the medullary cavity
what does the extracellular matrix consist of?
15% water
30% collagen
55% crystallized mineral salts
What makes up hydroxyapatite?
mineral salts
calcium phosphate
calcium hydroxide
what are the 4 types of cells in bones
osteoprogenitor cells
osteoblasts
osteoclasts
osteocytes
what are osteoprogenitor cells?
bone stem cells able to differentiate into other types of cells
what are osteoblasts
bone building cells that secrete matrix, initiates calcification
what are osteocytes?
mature bone cells
what are osteoclasts?
remodel bones and cause them to release calcium, bone resoption
what does compact bone do?
provides protection and support, strongest
what is spongy bone?
lightweight and provides tissue support, AKA trabecular or cancellous bone
where do periostea arteries enter the diaphysis?
the volkmanns canals
what is ossification?
process of bone formation
what are the 4 situations bones form
-during embryological and fetal development
-when bones grown before adulthood
-when bones remodel
-when fractures heal
what are the 2 types of ossification?
intramembranous
endochondral
where does intramembranous ossification occur?
in flat bones when a connective tissue membrane is replaced by bone
what is replaced in developing embryo and fetus?
Endochondral ossification replaces cartilage
where does endochondral ossification occur?
in epiphyseal plates of long bones with they grow in length
what makes bones thicken?
Osteoblasts and osteoclasts
what are factors the affect bone growth and remodeling?
minerals
vitamins
hormones
what are the steps in bone healing?
reactive phase
reparative phase
bone remodeling phase
what are the 2 steps in the reparative phase?
formation of fibrocartilaginous callus
bony callus
what is calcium and phosphorus factor in bone growth
make bone extracellular matrix hard
what is magnesiums factor in bone growth?
helps form bone extracellular matrix
what is fluorides factor in bone growth?
helps strengthen bone extracellular matrix
what is manganese factor in bone growth?
Activates enzymes involved in synthesis of bone extracellular matrix
what is Vitamin A factor in bone growth?
needed for osteoblasts, deficiency stunts bone growth
What is vitamin C factor in bone growth?
Needed for synthesis of collagen, deficiency leads to decreased collagen slowed bone growth and repair
What is vitamin D factor in bone growth
helps with calcium absorption, deficiency causes faulty calcification and slows bone growth.
what is Vitamin K and B12 factor in bone growth?
Needed for synthesis of bone proteins, deficiency leads to abnormal protein production in bone extracellular matrix and decrease bone density
what is growth hormones factor in bone growth?
promotes general growth of all body tissues, mainly by stimulating production of insulin-like growth factors.
what is growth hormone secreted from?
anterior lobe of pituitary gland
What is Insulin-Like growth factors function in bone growth?
promotes normal bone growth by stimulation osteoblasts and by increasing the synthesis of proteins needed to build new ones
what are thyroid hormones factor in bone growth?
Promote normal bone growth by stimulating osteoblasts
where is insulin-like growth factors secreted from?
liver, bones and other tissues
What is insulins factor in bone growth?
promotes normal bone growth by increasing synthesis of bone proteins
what is Parathyroid hormones factor in bone growth?
promotes bone resorption by osteoclasts, enhances recovery of calcium ions from urine and promotes formation of the active form of vitamin D
what is calcitonins factor in bone growth?
inhibits bone resorption by osteoclasts
what is osteoporosis
when bone resorption outpaces formation
what is rickets and osteomalacia
inadequate calcification of extracellular bone matrix,
what does Ricketts affect?
affects children, leads to bow legs deformed skull ribs pelvis
What does Osteomalacia affect?
adults and causes painful/tender bones and fractures with minor trauma
what is osteoarthritis?
degeneration of articular cartilage, leads to friction of bone on bone
What is Osteomyelitis
infection of bone
what is osteopenia
reduced bone mass below normal
where does hematopoiesis happen?
in the red marrow
