Chapter 33: MNT of Musculoskeletal Disorders Flashcards
musculoskeletal system includes (3)
bones, joints, and muscles
musculoskeletal system has associated structures (2)
ligaments and tendons
bone structure and bone physiology - bone composition
a connective tissue in which the intercellular matrix has been impregnated with inorganic calcium salts so that it has great tensile and compressible strength but is light enough to be moved by coordinated muscle contraction
bone
bone structure and bone physiology
the intercellular matrix is composed of 2 substances
organic matter and inorganic salts
intercellular matrix
constitutes about 1/3 of the dry weight of bone
organic matter
intercellular matrix
it includes bone cells. blood vessels, and nerves
organic matter
intercellular matrix
consist of collagen fibers embedded in an amorphous ground substance
organic matter
intercellular matrix
make up the other 2/3 of the dry weight of the bone
inorganic salts
intercellular matrix
consist of hydroxyapatite
inorganic salts
inorganic salts
an insoluble microcrystalline structure of calcium phosphate salts, and small amounts of calcium carbonate and calcium fluoride
hydroxyapatite
bone types
2 types of mature bones
cancellous or spongy bone and compact bone
bone types
found in the interior of bones and is composed of trabeculae or spicules of bone, which form a lattice-like pattern
cancellous or spongy bone
cancellous or spongy bone
the lattice-like structures are line with _____ and filled with either red or yellow bone marrow
osteogenic cells
cancellous or spongy bone
relatively light yet its structure has considerable tensile strength and weight bearing properties
cancellous bone
intercellular matrix
has a densely packed calcified intercellular matrix that makes it more rigid than cancellous bone
compact bone
intercellular matrix
it has the major component of tubular bones
compact bone
intercellular matrix
found along the lines of stress on long bones and forms an outer protective shell on other bones
compact bone
4 types of bone cells that participate in the formation and maintenance of bone tissue
osteogenic cells, osteoblast, osteocytes, osteoclasts
type of bone cells
function: undifferentiated that differentiate into osteoblasts
osteogenic cells
type of bone cells
function: found in the periosteum, endosteum, and epiphyseal growth plate growing bones
osteogenic cells
type of bone cells
function: bone-building cells that synthesize and secrete the organic matrix of bone
osteoblast
type of bone cells
function: also participates in the calcification of the organic matter
osteoblast
type of bone cells
function: mature bone cells that function in the maintenance of bone matrix
osteocytes
type of bone cells
function: play an active role in releasing calcium into the blood
osteocytes
type of bone cells
function: bone cells responsible for the resorption of bone matrix and the release of calcium and phosphate from the bone
osteoclasts
bone classification (based on shapes) - 4
long bones, short bones, flat bones, irregular bones
bone classification
found in the upper and lower extremities
long bones
bone classification
long bones has a shaft or diaphysis and 2 ends, called
epiphyses
bone classification
are irregularly shaped bones located in the ankle and the wrist.
except for their surface, which is compact bone, these bones are spongy throughout
short bones
bone classification
composed of a layer of spongy bone between 2 layers of compact bone
found in areas such as the skull and rib cage, where extensive protection of underlying structures is needed or, as in the scapula, where a broad surface for muscle attachment must be provided
flat bones
bone classification
because of their shapes, cannot be classified such bones as the previous group
this group included such bones as the vertebrae and the bones of the jaw
irregular bones
calcium homeostasis
the _____ serves as a reservoir of calcium and other minerals that are used by other tissued of the body
bone tissue
calcium homeostasis
the concentration of calcium in blood and other extracellular fluids is regulated by complex mechanisms that balance calcium intake and excretion with bodily needs
-
calcium homeostasis
when calcium intake is not adequate, homeostasis is maintained by drawing on mineral from bone to keep the serum calcium ion concentration at its set level
-
calcium homeostasis - the homeostatic mechanism is regulated by (3)
parathyroid hormone, calcitonin, vitamin d
calcium homeostasis
one of the most important regulators of calcium and phosphate in the blood
parathyroid hormone (PTH)
calcium homeostasis
hormone is secreted by the parathyroid glands, located on the posterior outer surface of the thyroid gland
parathyroid gland (PTH)
calcium homeostasis
acts to prevent serum calcium levels from falling below and serum phosphate levels from rising above normal physiologic concentrations
parathyroid hormone (PTH)
calcium homeostasis
functions of?
-release of calcium from the bone
-conservation of calcium by the kidney
-enhanced intestinal absorption of calcium through vitamin d, and
-reduction of serum phosphate
PTH
calcium homeostasis
secreted by the parafollicular or C, cells of the thyroid gland
calcitonin
calcium homeostasis
inhibits the release of calcium from bine into the extracellular fluid
calcitonin
calcium homeostasis
reduces the renal tubular reabsorption of calcium and phosphate
calcitonin
calcium homeostasis
the hormonal form of vitamin d, calcitriol, plays an adaptational role by increasing the efficiency of intestinal calcium absorption in the upper half of the small bowel when dietary calcium is adequate
vitamin d
calcium homeostasis
also has a direct effect on osteoblasts to increase the formation of several bone matrix proteins and other local factors needed for new bone formation and the suppression of bone degradation
vitamin d
is the term applied to the growth of the skeleton until mature height is achieved
bone modeling
bone modeling
elongate and widen by undergoing great internal changes as external expansions in their structures
long bones
bone modeling
the process of formation of new bone occurs first and is followed by the _____ of old tissue
resorption
bone modeling
in long bones growth occurs both terminal epiphyses and circumferentially in _____; at each location, cells undergo division and contribute to the formation of new bone tissue
lamella
bone modeling
bone modeling is completed in girls by age _____ and in boys _____
16-18 (G); 18-20 (B)
bone modeling
after growth cease, gains in bone tissue may continue by process known as _____
bone consolidation
bone modeling
the major event of the skeleton in early life is _____, whereas later life is the loss of bone
growth
bone modeling
peak bone mineral density is typically achieved by age _____;
post-menopausal women typically enter the fracture risk range after age 60, men have more gradual decline in bone mineral density, which starts at 50 y/o
30
bone mass
is a generic term referring to bone mineral content but not to bone mineral density
bone mass
bone mass
more appropriately used in assessing the amount of bone accumulated before the cessation of growth (height gain)
bome mineral content (BNC)
bone mass
used to describe bone after the developmental period is completed
term that is more often used for monitoring bone changes in adults
bone mineral density (BMD)
measurement - bone mineral content and bone mineral density
measures bine mass on the basis of tissue absorption of photons produced by 1 or 2 mono-energetic x-ray tubes
bone densitometry
accumulation of bone mass
during the growth periods of childhood, puberty, and into early adulthood, formation exceeds the _____ of bone
resorption
accumulation of bone mass
the age when BMD acquisition ceases varies, depending not only on diet but also on physical activity and strain loading on the skeleton
-
accumulation of bone mass
the consumption of both calcium supplements and calcium-enriched foods contributes to increased bone accumulation in the young
-
accumulation of bone mass
in young adult women who have children, the loading related to lifting and carrying of children may also improve skeletal mass and density
-
is greater in men than in women because of their larger frame size
peak bone mass (PBM)
peak bone mass (PBM)
both the _____ components of body composition contribute to the differences in
lean and fat components
also related to both dietary calcium intakes and weight-bearing PA
peak bone mass (PBM)
result of changes in the hormone-directed mechanisms that govern bone remodeling
loss of bone mass
