It's Bone Bro 2.0
what proteins/substances gives bone its hardness?
calcium phosphate and hydroxyapatite
where does growth in length occur in bones? until when?
- epiphyseal plate (growth plate)
- until ages 18-21 where bone stops growing in length and epiphyseal line forms from plate
what is intramembranous ossification?
when compact and spongy bone develops directly from sheets of mesenchymal CT
what are the three range of motions of joints
synarthrotic = no movement, ampiarthrotic = little movement, diarthrotic = full movement
why are synovial joints unique?
they are the only joints with a cavity
why is bone dynamic in nature?
osteoclasts continually break down old bone while osteoblasts continually form new bone
once the perichondrium produces a thin collar of bone around shaft, it becomes known as
periosteum
True or false: during a body emergency red marrow changes to yellow marrow
FALSE
what is the function of synovial fluid in synovial cavities?
reduces friction and acts as a lubricant for the joint during movement
what does the excretion of sebum in sebaceous glands do?
- naturally lubricates dry/dead layer of keratinized skin to make cells more pliable
- antibacterial properties
the spaces in many spongy bones contain _____ for ______?
red blood marrow for hematopoeisis
what is growth in diameter called and quickly describe process
appositional growth, osteoblasts in periosteum add success layers of bone called circumferential lamella and at same time osteoclasts on interior surface resorb bone and widen marrow cavity
what do osteoblasts secrete in intramembranous ossification
osteoid (organic matrix collagen + ground substances/proteoglycans)
what is the nucleus pulposis?
inner gel material of intervertebral disc, makes up 40%, composed of loose collagen fibers, water, and protein
periosteom covers entire outer surface of bone except for where? why?
@ joint surfaces and articular cartilage sites. Joint surfaces are sites of tension and friction, periosteum is vascular. The tension and friction that goes on in that area would damage the vascular tissue and any nerves/vessels in it
what is diploe bone?
2 layers of compact bone and interior of spongy bone that work together to protect internal organs
name and describe the zones of the epiphyseal plate
reserve- contains hyaline cartilage and is always maintained
proliferative- closer to diaphysis, contains of slightly larger chondrocytes (starts dividing)
hypertrophy- contains larger chondrocytes than proliferative zone
zone of calcification/resorption- closest to diaphysis becomes calcified and removed
function of red bone marrow and yellow bone marrow
creates red blood cells, white bloods cells, platelets
made mostly of fat, fat storage, inactive
what are the 2 types of fibrous joints and example of each
suture: synarthrotic joints that connect bones of skull, have serrated edges that lock with connective tissue fibers
syndesmosis: joint which ligament connects 2 bones allowing little movement (ampithrotic)
- ex: distal join of tibia and fibula
what two fibers are found in the reticular layer of dermis?
- elastic fibers which provide elasticity
- collagen fibers which provide structure and tensile strength
what are the two membranes of bone and where are they located?
endosteum- delicate membrane that lines medullary cavities
periosteum- fibrous membrane that covers outer surface of bone
what are periosteal buds and what do they do (generally)?
they are vascular buds which contain blood vessels, osteoblasts, osteoclasts, and hemocytoblasts (hemopoetic cells) that migrate into cavities within the calcified cartilage matrix
which bones form from intramembranous oss? (at least 2)
flat bones of skull, maxilla, mandible, clavicles
2 types of cartilagenous joints and examples
synchondrosis: immovable cartilage joint
- ex: growth plate, joint b/w 1st rib pair and sternum
symphysis: consists of fibrocartilagenous pad that connects two boness
- ex: pubic symphysis, intervertebral disc
what is a herniated disc?
when the nucleus pulposis spreads out and pushes on/compresses nerve root