Bone Physiology Flashcards
trabecular bone, inner bone
spongy bone
dense bone (osteons), outer bone
compact bone
consist of bones, cartilage, ligaments, and tendons and accounts for about 20 percent of body weight
skeletal system
rigid framework that support and protect the soft organs of the body
skeleton
bone that surround the brain to make it less vulnerable to injury
cranium
surround and protect the spinal cord
vertebrae
help protect the heart and lungs of the thorax
rib cage
contains large amount of calcium salts, the most important being calcium phosphate
intercellular matrix
released from the bones so that there will be an adequate supply for metabolic needs
calcium
when blood calcium levels are increased, the excess calcium is stored here
bone matrix
formation of blood cells, mostly take place in the red marrow of the bones
hematopoiesis
where red marrow is found in infants
bone cavities
limited to spongy bone in the skull, ribs, sternum, clavicles, vertebrae, and pelvis in adults
red marrow
Functions in the formation of red blood, white blood cells, and blood platelets
red bone marrow
Bone is comprised of (3)
cells
fibers
extracellular material
Two main types of bone tissue
compact
spongy
surrounds the spongy bone tissue
compact bone
Three types of cells that contribute to bone homeostasis
osteoblast
osteocytes
osteoclast
bone-forming cell
osteoblast
resorb or break down bone
osteoclast
mature bone cells
osteocytes
consist of closely packed osteons or haversian systems
compact bone
are a series of tubes around narrow channels formed by lamellae
haversian systems
consists of a central canal called the haversian canal
osteon
surrounded by concentric rings (lamellae) of matrix
haversian canal
where the osteocytes are located
lacunae
small channels that radiate from the lacunae to the osteonic (haversian) canal to provide passageway through the hard matrix
canaliculi
space inside the long bones
medullary cavity
main component of the bone
matrix
where blood vessels interconnect in the long axis of the bone
perforating canals
connect central canals to one another
volkmann canals
lighter and less than compact bone
spongy (cancellous) bone
Consist of trabeculae and bars of bone adjacent to small, irregular cavities that contain red bone marrow
spongy bone
Canaliculi connect to adjacent cavities instead of a central haversian canal to receive the blood supply
spongy bone
bone can develop by two processes
intramembranous ossification
endochondral bone formation
when osteoblast begin to make bone in mesenchymal connective tissue
intramembranous ossification
when osteoblasts begin to make bone in cartilage matrix
endochondral bone formation
woven bone, there is random collagen fiber orientation temporary bone that is removed or replaced with secondary bone
primary bone
known as lamellar bone, parallel collagen fibers arranged in layers, can become permanent but can be continuously remodeled
secondary bone
cortical bone, thick bone that requires internal blood supply; osteons
compact bone
known as spongy bone and cancellous bone, thin bone that can be nourished from outside
trabecular bone
Appears during development and repair; always looks trabecular
primary bone
Randomly oriented collagen fibers
primary bone
Temporary; usually replaced by mature lamellar bone or removed to make marrow cavity
primary bone
Can be compact or spongy/trabecular
secondary bone
Osteocytes in lacunae are between lamellae
secondary bone
arise from osteoprogenitor cells and these tumors are characterized by production of disorganized woven bone from mesenchyme
osteosarcoma
bone is deposited in connective tissue
intramembranous ossification
Type of bone development responsible for the formation of flat bones of skull and mandible
intramembranous ossification
Also responsible for initiation of bone formation in diaphysis in the bone collar
intramembranous ossification
Responsible for growth in diameter of long bones
intramembranous ossification
replacement of cartilage model with bone
endochondral ossification
Type of bone development for growth of length in long bones
endochondral bone formation
reserve of cells that will supply the other zones
resting cartilage
chondrocytes are actively proliferating, cells will appear in long columns
what stage
proliferation
chondrocytes stop dividing, swell, and secrete components to promote calcification
what stage of endochondral ossificaiton
maturation
chondrocytes will release substances that will begin matrix calcification by forming hydroxyapatite crystals (Chondrocytes die)
what stage of endochondral ossification
calcification
capillaries in osteoprogenitor cells will invade the cavities in the chondrocytes have died
what stage of endochondral bone formation
ossification
bone growth will continue until the closure of these
epiphyseal growth plate
acromegaly before growth plate closure, proportional growth in all body tissues
gigantism
changes in face shape with aging, after growth plate pressure
acromegaly
development of bones
osteogenesis
Osteoblasts migrate to the membrane and deposit bony matrix around themselves
type of ossificaiton
intramembranous ossification
when osteoblast are surrounded by matrix they are called this
osteocytes
involves the replacement of hyaline cartilage with bony tissue
endochondral ossification
bones formed by endochondral ossification
endochondral bones
Future bones are first formed as hyaline cartilage models, but during the third month after conception, the perichondrium that surrounds the hyaline cartilage models becomes infiltrated with blood vessels and osteoblast and changes into a periosteum
endochondral ossification
when osteoblast penetrate the disintegrating cartilage and replace it
with spongy bone
primary ossification center
break down the newly formed bone to open up the medullary cavity
osteoclast
occurs after birth in the epiphyses, similar to that in the diaphysis except that spongy bone is retained instead of being broken down to form a medullary cavity
secondary ossification center
When secondary ossification is complete, the hyaline cartilage is totally replaced by bone except in two areas:
articular cartilage
epiphyseal plate
region of hyaline cartilage that remain over the surface of the epiphysis
articular cartilage
area of cartilage remaining between the epiphysis and diaphysis
epiphyseal plate
process in which the cartilage at the region of the epiphyseal plate continues to grow
mitosis
nfluenced by growth hormone from the anterior pituitary gland and sex hormones from ovaries and testes
bone growth
increase in diameter in response to stress from increased muscle activity or to weight
appositional growth
number of bones in the human skeleton
206
Bones is divided into two groups based on location
axial
appendicular
long axis of body, includes the skull, vertebral column, rib cage
▪Includes 80 bones
▪Form the vertical axis of the body
axial skeleton
bones of upper and lower limbs, girdles attaching limbs to axial skeleton
appendicular skelton
Consist of 126 bones and includes the free appendages and their attachments to the axial skeleton
appendicular skeleton
Bones are classified according to one of four shapes:
long bones
short bone
flat bones
irregular bones
longer than they are wide, limb bones
long bones
▪Consist of a long shaft with two bulky ends or extremities
▪Primarily compact bone but may have large amount of spongy bone at the ends or extremities
▪ include bones of the thigh, leg, arm, and forearm
long bones
vary in size and number in different individuals
short bones
bones in wrist and ankle
cube-shaped bones
form within tendons (patella
sesamoid bones
▪Roughly cube shaped with vertical and horizontal dimensions approximately equal
▪Consist primarily of spongy bone, which is covered by a thin layer of compact bone
short bones
thin, flat, slightly curved found in sternum, scapulae, ribs, most skull bones
flat bones
complicated shapes, vertebrae and hip bones
irregular bone
primarily spongy bone that is covered with a thin layer of compact bone
what shape of bone
irregular bone
bears all the body’s weight in the lower leg
tibia
how many skeleton in axial
80
two or more bones coming together
articulation/joint
2 methods of classifying joints:
degree of motion
structure
tissues and/or fluid that fills the joint space
structure
classified by amount of movement that joint can perform:
degree of motion
non-movable, ex. Bones of the skull
synarthrosis
Bomes come in very close contact and are separated by only a thin layer of fibrous connective tissue
what kind of joint
synarthrosis
slightly movable joint ex. Invertebral disc
what kind of joint
amphiarthrosis
Connected by hyaline cartilage or fibrocartilage
what kind of jjoint
amphiarthrosis
slightly movable joint in which there is a fibrocartilage pad between the two bones in the pelvic girdle
symphysis pubis
freely movable joint ex. Knee
diarthrosis
Ends of the opposing bones are covered with hyaline cartilage, the articular cartilage, and they are separated by a spaced called the joint cavity
diarthrosis
joint classified by what fills space within joint
structural classification
space between bones filled with fibrous tissue
fibrous joint
narrow fibrous joint found between most bones of the skull
what kind of fibrous joint
suture
an immovable joint in which bones are joined by connective tissue (e.g. between the fibula and tibia at the ankle
syndesmoses
ligaments anchoring the tooth to the gum
the specialized fibrous joint that anchors the root of a tooth into its bony socket within the maxillary bone (upper jaw) or mandible bone (lower jaw) of the skull
gomphosis
space between the bones is filled with cartilage
cartilaginous joint
space between bones is filled with fluid and surrounding supporting connective tissue
synovial joint
produces synovial fluid
synovial membrane
lubricant for the joint
synovial fluid
shaft of long bon; made up mostly of compact bone
diaphysis
broad end of long bone; mostly spongy bone
epihpysis
growth area between diaphysis and epiphysis
metaphysis
hyaline cartilage at joint
articular cartilage
fibrous covering over most of bone
periosteum
marrow with fat and blood cells
medullary cavity
membrane lining medullary cavity
endosteum
25% water, 25% collagen fibers, 50% mineral salts
what component of bone
matrx
found in periosteum
what kind of bone cell
osteogenic cells
formed in monocytes that wandered in the bone, digest bone matrix for normal bone turnover
osteoclast
stimulates calcium salt deposit in bone
calcitonin
increasing levels of calcium in the blood when they are low
parathyroid hormone
cylinders running parallel to long axis of bone
osteons
“lakes” between lamellae that contain osteocytes
lacunae
little canals, containing extensions of osteocytes, permit the flow of ECF between central canal and lacunae
canaliculi
carry blood and lymphatic vessels and nerves from periosteum, supply central canals and bone marrow
volkmann’s canals
known as ossification
bone formation
early connective tissue model, initial skeleton model replaced by bone tissue beginning at 6 weeks of embryonic life
mesenchyme
read the development of bone in intramembranous
+1
read the formatio of bone in endochondral
+1
incomplete break (crack) fracture
partial
bone broken into two or more pieces
kind of fracture
complete
broken not through skin
closed
broken ends break skin
open fracture
increase strength, help in balance and absorb shocks
curves
