Chapter 7: Bone Tissue Flashcards
organ system composed of bones cartilages and ligaments
skeletal system
forerunner of most bones; covers many joint surfaces of mature bones; made up of cells called CHONDROCYTES and jelly like ground substance and fibers
cartilage
hold bones together at joints
ligaments
attach muscle to bone
tendons
layer of dense irregular connective tissue that surrounds cartilage; resists outward expansion due to pressure
perichondrium
what are the 3 kinds of cartilage?
hyaline cartilage, elastic cartilage, and fibrocartilage
most abundant cartilage; chondrocytes appear spherical; collagen is the only fiber in the matrix; found in nose, ends of most bones, costal cartilages, larynx, and trachea; provides support through flexibility
hyaline cartilage (glass)
type of cartilage; contains many elastic fibers as well; able to tolerate repeated bending
elastic cartilage
type of cartilage: an intermediate between hyaline and dense regular connective tissue; resists strong compression and strong tension; consists of rows of thick collagen fibers; locations- pubic symphysis, menisci of knee, anulus fibrosus ligaments in discs between vertebrae
fibrocartilage
function of skeleton: limb bones and vertebrae support body; jaw bones support teeth; some bones support viscera
support
function of skeleton: buffers blood against large pH changes by altering phosphate and carbonate salt levels
acid base balance
function of skeleton: red bone marrow is the chief producer of blood cells
blood formation
function of skeleton: calcium and phosphate levels
electrolyte balance
connective tissue that consists of cells fibers and ground substance
bone
what are the 4 principle types of bone cells?
osteogenic cells; osteoblasts; osteocytes; osteoclasts
stem cells found in endosteum and inner layer of periosteum
osteogenic cells
bone forming cells; nonmitotic; secrete osteocalcin
osteoblasts
former osteoblasts that have become trapped in the matrix they deposited (when stressed produce biochemical signals that regulate bone remodeling (shape and density changes that are adaptive)
osteocytes
bone dissolving cells found on bone surface; same bone marrow stem cells that give rise to blood cells
osteoclasts
hormone that stimulates secretion of pancreas leading to bone formation; increases insulin sensitivity in adipocytes which limits the growth of adipose tissue
osteocalcin
collagen, carbohydrate-protein complexes, i.e glycosaminoglycans, proteoglycans, and glycoproteins
organic matter
85% hydroxyapatite (crystallized calcium phosphate salt); 10% calcium carbonate; other minerals such as fluoride, sodium potassium, magnesium
inorganic matter
combination of ceramic and polymer
composite material
disease caused by mineral deficiency resulting in soft deformed bones
rickets
brittle bone disease; defect in collagen deposition
osteogenesis imperfecta
layers of bone matrix in which all of the collagen fibers all run in the same direction (fibers of adjacent __________- always run in roughly opposite directions
lamellae
what does spongy bone consist of ?
lattice of bone covered with endosteum, slivers of bone called spicules, thin plates of bone called trabeculae, spaces filled with red bone marrow; few osteons and no central canals; provides strength with minimal weight
soft tissue occupying marrow cavities of long bones and small spaces of spongy bone
bone marrow
myeloid tissue; contains hemopoietic tissue, in nearly every bone in a child; found in the adult skull, vertebrae, ribs, sternum, part of pelvic girdle and proximal heads of humerus and femur
red marrow
fatty marrow that does not produce blood; can transform back into red marrow in case of chronic anemia
yellow marrow
formation of bone (two names)
osteogenesis; ossification
type of ossification; formed directly from mesenchyme
intramembranous ossification
type of ossification: develop initially from hyaline cartilage
endochondral ossification
bone growth lengthwise
interstitial growth
bone growth width
appositional growth
where cartilage transitions to bone; functions as growth zone where bone elongates
epiphyseal plate
condition where long bones stop growing in childhood (normal torso short limbs)
achondroplastic dwarfism
condition with lack of growth hormone; normal proportions with short stature
pituitary dwarfism
repairs microfractures, releases minerals into blood, reshapes bones in response to use and disuse
bone remodeling
architecture of bone determined by mechanical stresses placed on it
wolff’s law of bone
process in which calcium, phosphate and other ions are taken from blood and deposited in bone
mineral deposition
formation of calcified mass in an otherwise soft organ
abnormal calcification (ectopic ossification)
calcified mass
calculus
process of dissolving bone and releasing minerals into blood
mineral resorption
calcium deficiency
hypocalcemia
excessive calcium
hypercalcemia
most active form of vitamin D
calcitriol
secreted by c cells of thyroid gland when blood calcium levels rise way too high
calcitonin
secreted by parathyroid glands on the posterior surface of thyroid when calcium levels low in the blood
parathyroid hormone
break caused by abnormal trauma to bone (i.e fall)
stress fracture
break in bone weakened by disease
pathological fracture
procedure in which bone fragments are manipulated into their normal positions without surgery
closed reduction
involves surgical exposure of the bone and the use of plates, screws, or pins to realign the fragments
open reduction
normally used to stabilize and immobilize healing bone
cast
aligns the bone fragments by overriding force of the strong thigh muscles
traction
most common bone disease; severe loss of bone density
osteoporosis
deformity of spine due to vertebral bone loss
kyphosis
hormone that maintains bone density in both sexes inhibiting resorption by osteoclasts
estrogen
excessive proliferation of osteoclasts and resoprtion on excess bone with osteoblasts attempting to compensate by depositing extra bone
osteitis deformans (Paget’s disease)
inflammation of osseous tissue and bone marrow due to bacterial infection
osteomyelitis
most common and deadly form of bone cancer
osteosarcoma
