Lessons 8 & 9 Osseous Tissue Flashcards
what is the difference between ligaments and tendons?
ligaments: attach bones together at joints
tendons: attach muscle to bone
what are some roles of the skeleton?
- support
- protection
- movement
- electrolyte and acid-base balance
- blood formation
- hormone secretion
what is the structure of a flat bone and an example?
thin curved plates, two external layers of compact bone and internal layer of spongy bone. an example is the skull, ribs, scapula…
where are short bones found?
in the wrist and ankle
where are irregular bones found?
in the vertebrae and in some skull bones
give some examples of long bones.
humerus, radius, ulna, femur, metacarpals, metatarsals, phalanges
where is spongy bone typically found?
in the center of ends and shafts of long bones, and in the middle of nearly all others. covered by compact bone!!
where is compact bone typically found in the long bone?
the outer shell of a long bone, encloses the marrow (medullary) cavity
what is the epiphyseal line? how does that differ from an epiphyseal plate?
line is a remnant of childhood growth zone. the plate is found in growing bones (composed of cartilage) and is the site of growth. line replaces plate.
what do osteogenic/osteoprogenitor cells do?
they are mesenchymal stem cells that give rise to osteoblasts (found in the endosteum and inner layer of the periosteum)
what do osteoblasts do?
produce bone matrix, performs osteogenesis promoting mineralization and calcification
under stress, mitotic division of osteoblasts is stimulated to produce more bone matrix
what are osteocytes? what do they do?
when osteoblasts get trapped in bone matrix (in lacunae) it becomes osteocytes.
maintains bone matrix and can sometimes reabsorb or deposit bone matrix. act as strain sensors (signals to strengthen the bone
what is osteocalcin?
hormone secreted by osteoblasts and osteocytes, body’s stress response by stimulating secretion of insulin and increasing insulin sensitivity
what do osteoclasts do?
performs osteolysis/resorption (breakdown of bone as part of bone remodeling)
**do not develop from osteogenic cells. produced by other types of cells (stem cells in bone marrow that give rise to macrophages)
what is the composition of osseous tissue matrix?
1/3 organic matter (synthesized by osteoblasts)
2/3 inorganic matter (provides support and strength)
you NEED both
what is vitamin D3’s function for bone health?
it absorbs calcium from your diet
what is rickets disease caused by?
mineral deficiency, specifically calcium from your diet, and can be from not enough UV light exposure (vitamin D3)
soft deformed bones
what is the difference between concentric lamellae, circumferential lamellae, and interstitial lamellae?
concentric: layers around a central (haversian) canal
circumferential: encircles the inner outer region of dense bone
interstitial: fill irregular regions between osteons
how does the spongy bone structure relate to mechanical stress?
spongy bone has greater surface area than compact bone meaning they are the first to be exposed to osteoclast breakdown
what is red bone marrow also known as?
myeloid tissue
produces RBCs!