Question | Answer |
6 bone shapes | 1. long bones 2. flat bones 3. sutural bones 4. irregular bones 5. short bones 6. sesamoid bones |
long bones | long and thin |
where can long bones be found? | arms (humorous ulna and radius), legs 9femur tibia and fibula), hands, feet, fingers, and toes |
flat bones | thin with parallel surfaces (sandwich with spongy bone in the middle) |
where can flat bones be found? | skull, sternum, ribs, and scapula |
sutural bones | small and irregular |
where can sutural bones be found? | between the flat bones of the skull |
irregular bones | complex shapes |
where can irregular bones be found? | spinal vertebrae and pelvic bones |
short bones | small and thick |
where can short bones be found? | ankle and wrist bones |
sesamoid bones | small and flat |
where can sesamoid bones be found? | inside tendons near joint of knees, hands, and feet |
elevations and projections | process and ramus |
process | projection or bump |
ramus | extension of a bone making an angle with the rest of the structure |
processes formed where tendons/ligaments attach | trochanter, tuberosity, tubercle, crest, line, spine |
trochanter | large rough projection |
tuberosity | smaller rough projection |
tubercle | small rounded projection |
crest | prominent ridge |
line | low ridge |
spine | pointed or narrow process |
process formed for articulation with adjacent bones | head, neck, condyle, trochlea, facet |
head | end of an epiphysis, separated from the shaft by a neck |
neck | narrow connection between the epiphysis and diaphysis |
condyle | rounded articular process |
trochlea | smooth grooved articular process shaped like a pulley |
facet | small flat articular surface |
depressions | fossa and sulcus |
fossa | shallow depression |
sulcus | narrow groove |
openings | foramen, canal, meatus, sinus, fissure |
foramen | passageway for blood vessels or nerves |
canal | channel/duct |
meatus | passageway through a bone |
sinus | chamber within a bone; usually filled with air |
fissure | elongated cleft or slit |
anatomy of a long bone: diaphysis | shaft |
anatomy of a long bone: epiphysis | wide part of the end (tip); articulates with other bones |
anatomy of a long bone: metaphysis | between shaft (diaphysis) and tips (epiphysis) meet |
an example of a long bone | femur |
diaphysis | compact bone; has a central space called the marrow cavity |
epiphysis | mostly spongy bone; covered with layer of compact bone (cortex) |
flat bones | sandwich of spongy bone; spongy bone between 2 layers of compact bone |
an example of a flat bone | parietal bone of skull |
what type of tissue is bone? | supportive connective |
bone | solid matrix of calcium salt deposits and collagen fibers |
bone matrix | canal organized around blood vessels |
canaliculi | pathway for blood vessels |
periosteum | outer surface; what you can see |
matrix minerals | 2/3 calcium phosphate; reacts with calcium hydroxide to form hydroxyapatite |
hydroxyapatite | withstand compression |
matrix proteins | 1/3 protein fibers (collagen); allows bone twisting and causes flexibility |
bone cells | 2% of mass; osteocytes, osteoblasts, osteoprogenitor cells, osteoclasts |
osteocytes | mature bone cells; between layers (lamellae) of matrix in lacunae (central canal) |
osteocyte function | maintain protein and mineral content of matrix |
osteoblasts | immature cells that become osteocytes |
osteoprogenitor cells | mesenchymal stem cells that produce osteoblasts |
what type of matrix do osteoblasts secrete? | osteogenesis |
where are osteoprogenitor cells located? | inner layer of periosteum (endosteum) |
what do osteoprogenitor cells assist in? | fracture repair |
what do osetoclasts do? | break down bone |
what are osetoclasts? | giant cells that dissolve bone minerals (osteolysis) |
what do osetoclasts cause? | resorption |
bone homeostatis | bone building (osteoblasts) and bone recycling (osteoclasts) balancing |
what happens if bone breaks down more than it can be built? | become weak |
what does exercise cause bone to do? | build bone |
another name for osteon | haversian system |
what is the osteon? | basic building block of bone |
how are osteons arranged? | around the central canal (concentric lamellae) |
another name for central canal | haversian canal |
what is within the central canal? | blood vessels |
another name for perforating canals? | Volkmann canals |
perforating canals run which way? | perpendicular to the central canal |
what do perforating canals do? | carry blood vessels deep into bone and marrow |
circumferential lamellae | lamellae wrapped around the long bone |
what does the circumferential lamellae hold together? | the osteons |
spongy bone has no what? | osteons |
name of the matrix of spongy bone | trabeculae |
trabeculae has no what? | blood vessels |
how do nutrients reach osteocytes? | diffusion |
where is red marrow found? | space between the trabeculae |
what does yellow marrow do? | it is adipose; stores fat |
weight bearing bones: femur transfers weight from the hip joint to the knee joint. which side is the tension on? | lateral side |
eight bearing bones: femur transfers weight from the hip joint to the knee joint. which side is the compression on? | medial side |
where is the periosteum? | outside |
where is the endosteum? | inside |
what does the periostem do? | covers all bones |
what is the periosteum made of? | outer fibrous layer and inner cellular layer |
another name for perforating fibers | sharpey fibers |
functions of the periosteum | 1. isolates bone 2. circulatory and nerve supply of bone 3. growth and repair |
endosteum | incomplete (partial exposed) layer that lines the marrow cavity; cover trabeculae in spongy bone and lines central canal |
what is contained in the endosteum? | osteoblast, osteoclasts, and osteoprogenitor cells |
what does the endostuem help with? | bone growth and repair |
what age does the human bone stop growing? | 25 |
osteogenesis | bone formation |
ossification | replacing other tissues with bone |
calcification | process of depositing calcium salts |
when does calcification occur? | during ossification of other tissues |
what are the two forms of ossification? | intramembranous and endochondral |
endochondral ossification replaces what as bone? | hyaline cartilage |
how many steps is the endochondral ossification? | 6 |
endochondral ossification step 1 of 6 | enlarging condrocytes in center of cartilage (calcifying matrix) |
endochondral ossification step 2 of 6 | blood vessels grow around edges; perichondrium changes to osteoblasts (immature bone cells)-produces layer of superficial bone |
endochondral ossification step 3 of 6 | blood vessels enter cartilage brining fibroblasts that become osteoblasts; spongy bone develops an becomes primary ossification center |
endochondral ossification step 4 of 6 | remodeling creates a marrow cavity; bone replaces cartilage at metaphysis |
endochondral ossification step 5 of 6 | capillaries and osteoblasts enter epiphyses; this creates secondary ossification center |
endochondral ossification step 6 of 6 | epiphysis fills with spongy bone |
step 6; in joint cavity | articulation cartilage |
step 6; at metaphysis | epiphyseal cartilage |
epiphyseal lines | after puberty; show on xrays as line, epiphyseal cartilage disappears |
appositional growth of endochondral ossification | compact bone thickens and strengthens long bone with layers of circumferential lamellae around the bone |
another name for intramembranous ossification | dermal ossification because it occurs in dermal bones such as mandible, flat bones of skull, and clavicle |
how many steps are involved in intramembranous ossification? | 3 |
intramembranous ossification step 1 of 3 | mesenchymal (stem cells) cells come together and differentiate into osteoblasts; begins at ossification center; develops projections called spicules |
intramembranous ossification step 2 of 3 | blood vessels grow into the area; spicules connect trapping in blood vessels |
intramembranous ossification step 3 of 3 | spongy bone develops and remodels into osteons of compact bone, periosteum, and marrow cavities (hardening) |
FOP-fibrodysplasia ossificans progressiva | abnormal tissue that attacks other tissues and turns them to bone; very aggressive and debilitating |
3 major sets of blood vessels | nutrient artery and supply, metaphyseal vessels, and periosteal vessels |
nutrient arteries | supplies diaphysis |
metaphyseal vessels | supplies epiphyseal cartilage |
periosteal vessels | blood to superficial osteons of shaft |
periosteum also contains lymph and nerves. what does each do? | lymph-immunity; sensory nerves |
bone remodeling | recycling and renewing bone |
what does remodeling involve? | osteocytes, osteoblasts, and osteoclasts |
what happens to heavily stressed bones? | become thicker and stronger |
bone degeneration | very quick |
how much mass can be lost in a few weeks of inactivity? | 1/3 |
effects of hormones and nutrition on bone | normal bone growth and maintenance rely on nutrition and hormones |
source of what two minerals are necessary for bone? | calcium and phosphate salts |
where is calcitrol made? | kidney |
what does calcitrol absorb? | calcium and phosphorus in digestive track |
what is calcitrol made from? | vitamin D3 |
what is vitamin D3 called before it becomes calcitrol? | chloecalciferol |
what vitamin is required for collagen synthesis and stimulates osteoblast differentiation? | vitamin C |
vitamin c deficiency causing loss of bone mass and strength | scurvy |
this vitamin stimulates osteoblast activity | vitamin A |
these vitamins synthesize bone proteins | vitamins K and B12 |
growth hormone and thrroxine stimulate what? | bone growth |
estrogens and androgens stimulate what? | osteoblasts |
calcitonin and parathyroid hormone regulate what? | calcium and phosphate levels |
what causes gigantism? | tumor on pituitary gland |
what causes acromegally? | epiphyseal cartilage closes and increased bone mass |
marfan syndrome | connective tissue disorder; tall/thin; plyable |
what causes dwarfism? | lack of growth hormone |
what is the most abundant mineral in the body? | calcium |
what is calcium vital to? | membranes, neurons, and muscle cells (especially cardiac cells) |
what must happen to calcium ions in body fluids? | must be closely monitored |
how is homeostatis maintained? | calcitonin and parathyroid hormone |
where calcium is stored? | bones |
where calcium is absorbed? | digestive track |
where calcium is excreted? | kidneys |
what does parathyroid hormone(PTH) do? | increase blood calcium levels; increase absorption of calcium and decrease calcium excretion |
what does calcitonin do? | decrease blood calcium levels; inhibits osteoclast activity (bone degrading), and increase calcium excretion at kidneys |
where is the parathyroid? | in parathyroid the neck |
what secretes calcitonin? | c cells (parafollier cells) in thyroid |
what is a fracture? | crack or break in bone |
what are the 4 steps of bone fracture repair? | 4 steps |
step 1 of 4 of bone fracture repair: | bleeding makes clot; bone cells in area die |
step 2 of 4 of bone fracture repair: | calluses stabilize break-external callus surrounds break and internal callus develops in marrow |
step 3 of 4 of bone fracture repair: | osteoblasts replace central cartilage of external callus with spongy bone |
step 4 of 4 of bone fracture repair: | osteoblasts and clasts remodel the fracture for up to a year; reducing calluses |
what are the two types of fractures? | closed (simple) and open (compound) |
closed (simple) fracture | internal and does not break skin; simple to treat |
open (compound) | fracture that project through the skin; infection and uncontrolled bleeding occurs |
transverse fracture | break at a right angle along long axis of bone |
comminuted fracture | shattering |
what occurs with age? | bone becomes thinner and more weak |
osteopenia | decrease bone mass; starts at 30 or 40 and percentage degrades per 10 years |
osteoporosis | severe bone loss that makes holes in bone; affects normal function over age 45 |
estrogens and androgens maintain what? | bone mass |
bone loss in women accelerates what? | menopause |
cancerous tissue release what? | osteoclasts that degrade bone |
cancerous produce what? | severe osteoporosis -bone degrading |