Lesson 8 Flashcards
What does the skeletal system include?
206 bones, cartilage, ligaments, connective tissues
five primary functions of skeet’s system
- support
- storage of minerals and lipids
- blood cell production
- protection
- leverage(force of motion)
what are bones classified by
shape, bone markings, internal tissue organization
what are the 6 bone shapes
- sutural
- irregular
- short
- long
- flat
- sesamoid
what bones are small, irregular, and found between the flat bones of the skull?
sutural bones
what are examples of irregular bones with complex shapes?
spinal vertebrae, pelvic bones, some skull bones
what are examples of short bones that are small and thick?
ankle and wrist bones(tarsals)
what are examples of flat bones with thins and parallel surfaces?
roof of skull, sternum, ribs, scapulae
what are examples of long bones that are long and thin?
arms, legs, hands, feet, fingers, toes
what are examples of sesamoid bones that are small and flat and shaped like sesame seeds?
develop in tendons near joints of knees, hands, feet
patella(kneecap)
what bones account for disparities in total number of bones?
sutural and sesamoid
what are these bone markings for: depressions, groves, tunnels along the surface
blood and nerves lie alongside and penetrate into bones
what are these bone markings for: elevations or projections?
tendons and ligaments attach, articulations with other bones occur
what is the structure of a long bone?
diaphysis, epiphysis, metaphysis
what is the tubular shaft of the bone that consists of compact bone and a medullary cavity?
diaphysis
what are the wide ends of long bones that consist of spongy bone covered with compact bone?
epiphysis
where do the epiphysis and diaphysis meet on long bones?
metaphysis
Which bone resembles a sandwich of spongy bone between two layers of compact bone?
flat bone
in the cranium, what is the layer of spongy bone between the compact bone?
diploë
This bone contains red bone marrow in spongy bone, but had no medullary cavity unlike long bones
flat bone
what is bone(osseous) tissue?
dense, supportive connective tissue that contains specialized cells and produces solid matrix of calcium salt deposits called collagen fibers
BONE TISSUE: had a dense matrix containing?
deposits of calcium salts, osteocytes within lucunae
BONE TISSUE: what are osteocytes organized around blood vessels and connected to other osteocytes by?
gap junctions
BONE TISSUE: what are canaliculi?
small canals that connect lacunae to each other and to blood vessels of the central canal
BONE TISSUE: what doues canaliculi do?
forms pathways for blood vessels for exchange of nutrients and waste
BONE TISSUE: what is the periosteum?
it covers the outer surfaces of bones
what does the periosteum consist of?
outer fibrous and inner cellular layers
what is bone matrix composed of?
minerals (2/3 calcium phosphate) and matrix proteins (1/3 protein fibers like collagen)
calcium phosphate reacts with calcium hydroxide in bone matrix to form
hydroxyapatite
what allows bones to be strong but still flexible?
bone matrix of calcium crystals
what are the four types of bone cells?
- osteoprogenitor
- osteoblasts
- osteocytes
- osteoclasts
what are osteoprogenitor cells and where are they located?
mesenchymal stem cells that divide to produce osteoblasts
located in the endosteum: lines the medullary cavity and passageway for blood vessels in matrix
which cell type is important in fracture repair?
osteoprogenitor
what are immature bone cells that secrete matrix compounds(osteogenesis)?
osteoblasts
what is a matrix produced by osteoblasts, but not yet calcified by calcium salts to form bone?
osteoid
when osteoblasts are surrounded by bone what do they become?
osteocytes
what are mature bone cells that maintain the bone matrix?
osteocytes
where do osteocytes live?
in lucunae between layers(lumallae) of matrix
how do osteocytes connect?
by cytoplasmic extensions through canaliculi in lamellae
what are two major functions of osteocytes?
- maintain protein and mineral content of matrix
2. help repair damaged bone
what are giant, multinucleate(50 or more nuclei) cells that derive from stem cells that produce macrophages?
osteoclasts
do osteoclasts develop from osteoprogenitor cells?
no
what do osteoclasts do?
secrete acids and protein digesting enzymes
what happens during homeostasis of bone tissue?
bone building by osteoblasts and bone recycling by osteoclasts mist balance
if there’s more breakdown than building, bones become weak
true or false: exercise causes osteoclasts to build bone faster than osteoblasts can break down bone
false
true or false: exercise causes osteoblasts to build bone faster than osteoclasts can break down bone
trueee
COMPACT BONE: what is the basic unit of mature compact bone?
osteon
COMPACT BONE: what are arranged in concentric lamallae around a central canal containing blood vessels
osteocytes
COMPACT BONE: what are perforating canals?
perpendicular to the central canal, carry blood vessels into bone and marrow
COMPACT BONE: what type of lamellae wraps around the long bone, encircling multiple osteons,
circumferential lamellae
SPONGY BONE: the matrix forms an open network of-
trabeculae- bone fiber bundles
SPONGY BONE: the space between trabeculae is filled with red bone marrow, which does what?
supplies nutrients to osteocytes and forms red blood cells, it has blood vessels
SPONGY BONE: where is yellow bone marrow found and why is it yellow?
found in the medullary cavity and in spongy bone of some bones like the femur
yellow because it stores fat(adipose tissue)
compact bone is covered with a membrane with what on the outside?
periosteum
what is periosteum made up of?
outer fibrous layer and inner cellular layer
what to perforating fibers do?
connects with collagen bone fibers and joint capsules to strengthen tendon and ligament attachment to bone
what are the three functions of periosteum?
- isolates bone from surrounding tissue
- provides a route for circulatory and nervous supply
- participated in bone growth and repair
compact bone is covered with a membrane with what on the inside?
endosteum
where is the endosteum found?
lines the medullary cavity, lines central canals
covers trabeculae in spongy bone
which cell types does the endosteum contain?
osteoblasts, osteoclasts, and osteoprogenitor cells
