intramembranous ossification can also be called what?
intramembranous ossification can also be called dermal ossification because it take place where?
mandible and clavicle are considered what type of bones because of where they are produced?
There are how many main steps to intramembranous ossification?
3 main steps
Mesenchmal cells aggregate -differentiate into osteoblasts -begin ossification at the ossification center -develop prjections called spicules Is which step of intramembramous ossification?
When blood vessels grow into the area to supply the osteoblasts and spicules connect trapping blood vessels inside the bone, is which step of intramembranous ossification?
when spongy bone develops and is remodeled into osteons of compact bone, periosteum, or marrow cavities, is what step of intramembranous ossification?
ossifies bones that originate as hyaline cartiage is intramembranous ossification or endochondral ossification?
do many or few bones originate as hyaline cartilage?
how many steps occur in growth and endochondral ossification of long bones?
Condrocytes in the center of hyaline cartilage enlarge, form struts and calcify, causing chodrocytes to die and leave cartilage, is what step of endochondral ossification?
Blood bessels grow around the edges of the cartilage; cells in the perichondrium change to osteoblasts-producing a layer of superficial bone around the shaft which will continue to grow and become compact bone. is what step in endochondral ossification?
producing a layer of superficial bone around the shaft which will continue to grow and become compact bone. is example of what type of growth?
Blood vessels enter the cartilage; bringing fibroblasts that become osteoblasts; spongy bone develops at the primary ossification center. is what step of endochondral ossification?
which step of endochondral ossification does secondary possification centers form?
Remodeling creates a marrow cavity; bone replaces cartilage at the metaphyses. is which step of endochondral ossification?
capillaries and osteoblasts enter the epiphsis; creating 2 secondary ossification centers. is what step of endochondral ossification?
when the epiphysis fill with spongy bone; cartilage within the joint cavity is articulation cartilage; cartilage at the metaphysis is epiphyseal cartilage. is which step of endochondral ossification?
what type of growth happens in endochondral ossification?
when compact bone thickens and strengthens long bone with layers of circumferential lamellae is what type of growth in endochondral ossification?
when long bone stops growing, after puberty the epiphyseal cartilage does what?
when epiphyseal disappears, what forms?
when osteoclasts enlarge marrow cavity; osteons from around blood vessels in compact bone means the bone is what?
a mature bone
what are the 3 major sets of blood vessels devloped in mature bones?
nutrient artery and vein metaphyseal vessels periosteal vessels
What is a single pair of large blood bessels that enter the diaphysis through the nutrient foramen in a mature bone?
nutrient artery and vein
which mature bone has more than one pair of nutrient artery and vein?
which blood vessels of the mature bones supply the epiphyseal cartilage and is where bone growth occurs?
Which blood vessels of mature bones provid blood to the superficial steons and secondary ssification centers?
A network of lympatic vessels and sensory nerves are contained in the periosteum or the endosteum?
maintains itself and replaces mineral reserves is describes the adult skeleton or remodeling?
the adult skeleton
recycles and renews bone matrix; involves osteocytes (destroy), osteoblasts (build), and osteoclasts (eats) is describes what?
The bone continually does what? hint: the 3 r's
remodels, recycles, replace
is the turnover rate consistent or varied?
if deposition is greater than removal, the matrix and bone do what?
bone gets stronger and the matrix grows
if removal is faster than replacment, the matrix and bone do what?
matrix shrinks and bone gets weaker
what helps mineral recycling allowing bones to adappt to stress?
what effects heavily stressed bones become thicker and stronger?
how much bone mass can be lost in a few weeks of inactivity?
1/3 of bone mass
what causes bone degeneration?
normal bone growth and maintenance requires what 2 factors?
nutritional and hormonal factors
what hormone is made in the kidneys?
what horomone helps absorb calcium and phosphorus from in the digestive tract?
calcitriol requires what vitamin for synthesis?
what are the 2 most important mineral for bones?
calcium and phosphate
which vitamin is required for collage synthesis, and stimulates osteoblast differentiation?
what vitamin stimulates osteoblast activity?
which 2 vitamins help synthesize bone proteins?
vitamin K and vitamin B12
what are the 2 harmones that stimulate bone growth?
growth hormone and thyroxine hormons
what 2 hormones stimulate osteoblasts?
estrogens and androgens (steroids)
Calcitonin and parathyroid hormone regulate what 2 minerals level?
calcium and phospate levels
what is the most abundant mineral in the body?
bones are great at storing what major mineral?
calcium ions are vital to what 3 things? hint: first letters m,n,mc
membranes neurons muscle cells, especially heart cells
what vitamin is vital for the membranes?
what vitamin is vital for the neurons?
what vitamin is vital for muscle cells, especially heart cells?
calcium is regulated by which 2 harmones to maintain homeostasis?
calcitonin and parathyroid hormone
homeostasis is maintained by calcitonin and parathyroid hormone which control storage, absorption, and excretion. is example of what type of regulation?
Where is calcium stored?
Where is calcium absorbed?
the digestive tract
where is calcium excreted?
The parathyroid glands are produced where?
in the neck
when parathyroid hormone stimulate osteoclasts, increase intestinal absorption of calcium, and decrease calcium excretion at the kidneys. the parathyroid is increasing what?
increases calcium ion levels
what hormone is secreted by c cells (parafollicular cell) in thyroid?
when calcitonin inhibits osteoclast activity and increasing calcium excretion at kidneys, it is doing what to the calcium ion level?
decreases the calcium ion levels
calcium and phosphate ions in blood are lost where?
ions must be replaced to maintain what?
if not obtained fro diet, ions are removed from where?
if ions are removed from the skeleton, what happens to the bones?
it causes weakening bones
what are the 2 major componites to keeping bones strong?
exercise and nutrition
Cracks or breaks in bones caused by physical stress is called?
How many steps are there in fracture repair?
Bleeding produces a clot (fracture hematoma); establishes a fibrous network; then bone cells in the area die. is what step of fracture repair?
cells of the endosteum and periosteum divide and migrate into fracture zone; calluses begin to stabilize the break; external callus of cartilage and bone surrounds breaks; then internal callus develops in marrow cavity. is what step of fracture repair?
Osteoblasts replace central cartilage of external callus with spongy bone. is what step of fracrure repair?
osteoblasts and osteocytes remodel the fracture for up to a year creating compact bone and reducing bone calluses. is which step of fracture repair?
do bones become thicker and stronger with age?
osteopenia begins around what 10 year period?
age 30 to 40
do women or men lose 8% of bone mass per decade?
The epiphses, vertebrae, and jaws are most affected by what?
fragile limbs, reduction in height, and tooth loss are the effects of what?
severe bone loss, affects normal function, begins in some at age 45, and occurs with a higher percentage women than men, describes what dieses?