CH6: Bone Tissue & The Skeletal System

fracture hematoma

blood clot that forms at the site of a broken bone

hematopoiesis

production of blood cells, which occurs in the red marrow of the bones

open reduction

surgical exposure of a bone to reset a fracture

nervous system

the system that is the most impacted by having too high or too low calcium levels in the blood

diaphysis

tubular shaft that runs between the proximal and distal ends of a long bone

epiphyseal line

completely ossified remnant of the epiphyseal plate

long bone

cylinder-shaped bone that is longer than it is wide; functions as a lever

endosteum

delicate membranous lining of a bone's medullary cavity

compact bone

dense osseous tissue that can withstand compressive forces

fracture

broken bone

osteoclast

cell responsible for resorbing bone; breaks down bone with acid

ossification center

center of osteoblasts found in the early stages of intramembranous ossification

canaliculi

channels within the bone matrix that house one of an osteocyte's many cytoplasmic extensions that it uses to communicate and receive nutrients

osteoid

uncalcified bone matrix secreted by osteoblasts

osteon

Haversion system; basic structural unit of compact bone; made of concentric layers of calcified matrix

perforating canal

Volkmann's canal; channel that branches off from the central canal and houses vessels and nerves that extend to the periosteum and endosteum

paget's disease

a disease where the osteoclasts are overactive, the osteoblasts try to keep up but end up laying down brittle and weak bone; can lead to pain, bone fractures, and bone deformities.

hypocalcemia

abnormally low levels of calcium in the blood

sinus

air-filled space in bone

spongy bone

also called cancellous bone; trabeculated osseous tissue that supports shifts in weight distribution

cancellous bone

another name for spongy bone

Haversion canal

another word for central canal

Haversion system

another word for osteon

Volkmann's canal

another word for perforating canal

meatus

bone feature that is an opening into canal

facet

bone marking that is a flat surface; vertebrae

head

bone marking that is a prominent rounded surface

condyle

bone marking that is a rounded surface; on ends of ulna and radius

protuberance

bone marking that is protruding; chin

projection

bone markings where part of the surface sticks out above the rest of the surface, where tendons and ligaments attach

irregular bone

bone of complex shape; protects internal organs from compressive forces

osseous tissue

bone tissue; hard, dense connective tissue that forms the structural elements of the skeleton

pneumatized bones

bones that have an air cavity; example would be the sinuses

hydroxyapatite crystals

calcium phosphate and calcium hydroxide form to make

osteoblast

cell responsible for forming new bone

external callus

collar of hyaline cartilage and bone that forms around the outside of a fracture

hypocalcemia

condition characterized by abnormally LOW levels of calcium

hypercalcemia

condition characterized by abnormally high levels of calcium

yellow marrow

connective tissue in the interior cavity of a bone where fat is stored

red marrow

connective tissue in the interior cavity of a bone where hematopoiesis takes place

short bone

cube-shaped bone that is approximately equal in length, width, and thickness; provides limited motion

osteoporosis

disease characterized by a decrease in bone mass; occurs when the rate of bone resorption exceeds the rate of bone formation, a common occurrence as the body ages

osteogenesis imperfecta

disease where bones do not form properly, they are fragile and break easy, this is a result of a mutation that affects the body's collagen; commonly associated with bowed legs or spinal curvature

orthopedist

doctor who specializes in diagnosing and treating musculoskeletal disorders and injuries

fossa

elongated basin on bone

calcium ions

essential for muscle contractions and controlling the flow of other ions involved in the transmission of nerve impulses

internal callus

fibrocartilaginous matrix, in the endosteal region, between the two ends of a broken bone

perichondrium

fibrous membrane covering the outer surface of bone and continuous with ligaments

sulcus

groove in bone

interstitial growth

growth in length

appositional growth

growth in width

epiphyseal plate

growth plate; sheet of hyaline cartilage in the metaphysis of an immature bone; replaced by bone tissue as the organ grows in length

bone

hard, dense connective tissue that forms the structural elements of the skeleton

ligaments

holds bones together to add strength, can stretch to some extent, bone to bone

foramen

hole through bone

medullary cavity

hollow region of the diaphysis; filled with yellow marrow

growth hormone

hormone that increases length of long bones, enhances mineralization, and improves bone density

Calcitonin

hormone that inhibits osteoclast activity and stimulates calcium uptake by bones

calcitrol

hormone that stimulates absorption of calcium and phosphate from digestive tract; active form of vit. d

thyroxine

hormone that stimulates bone growth and promotes synthesis of the bone matrix

parathyroid hormone

hormone that stimulates osteoclast proliferation and resorption of bone by osteoclasts; promotes reabsorption of calcium by kidney tubules; indirectly increases calcium absorption by small intestine

sex hormones

hormones that promote osteoblastic activity and production of bone matrix; responsible for adolescent growth spurt; promote conversion of epiphyseal plate to epiphyseal line

sutural bones

irregular bones that show up inside sutures

diploë

layer of spongy bone, that is sandwiched between two layers of compact bone found in flat bones

central canal

longitudinal channel in the center of each osteon; contains blood vessels, nerves, and lymphatic vessels; also known as the Haversian canal

closed reduction

manual manipulation of a broken bone to set it into its natural position without surgery

lamellar bone

mature bone in sheets called lamellae

vitamin K

may work with vitamin D to help absorb calcium and supports bone mineralization

calcium

mineral needed to make crystals with phosphate that give bones their hardness, most abundant mineral in body and in bones

vitamin D

needed to help the small intestine absorb calcium

hole

opening or depression in a bone

skeletal system

organ system composed of bones and cartilage that provides for movement, support, and protection

plantigrade

organism that walks on all bones of the feet

unguligrade

organism that walks on it's nails or hooves

digitigrade

organism that walks only on the digits and toes

ossification

osteogenesis; bone formation

canal

passage in bone

intramembranous ossification

process by which bone forms directly from mesenchymal tissue

remodeling

process by which osteoclasts resorb old or damaged bone at the same time as and on the same surface where osteoblasts form new bone to replace that which is resorbed

endochondral ossification

process in which bone forms by replacing hyaline cartilage

modeling

process, during bone growth, by which bone is resorbed on one surface of a bone and deposited on another

process

prominence feature of bone; transverse process of vertebrae

projections

raised markings on a bone; spinous process of the vertebrae

omega-3 fatty acids

reduces inflammation that may interfere with osteoblast function

zone of calcified matrix

region of the epiphyseal plate closest to the diaphyseal end; functions to connect the epiphyseal plate to the diaphysis

reserve zone

region of the epiphyseal plate that anchors the plate to the osseous tissue of the epiphysis

zone of maturation and hypertrophy

region of the epiphyseal plate where chondrocytes from the proliferative zone grow and mature and contribute to the longitudinal growth of the epiphyseal plate

proliferative zone

region of the epiphysial plate that makes new chondrocytes to replace those that die at the disaphysial end of the plate and contributes to longitudinal growth of the epiphyseal plate

primary ossification center

region, deep in the periosteal collar, where bone development starts during endochondral ossification

crest

ridge on bone

tuberosity

rough surface on bone

cartilage

semi-rigid connective tissue found on the skeleton in areas where flexibility and smooth surfaces support movement

spine

sharp process of bone

line

slight, elongated ridge on bone

fissure

slit through bone

nutrient foramen

small opening in the middle of the external surface of the diaphysis, through which an artery enters the bone to provide nourishment

fovea

small pit on bone

sesamoid bone

small, round bone embedded in a tendon; protects the tendon from compressive forces

tubercle

small, rounded process on bone; think "hip"

lacuna

space in a bone that houses an osteocyte

trabeculae

spikes or sections of the lattice-like matrix in spongy bone

tendons

stretchy, springy, and connect muscle to bone

magnesium

structural component of bone (not fluoride)

fluoride

structural component of bone (not magnesium)

flat bone

thin and curved bone; serves as a point of attachment for muscles and protects internal organs

articular cartilage

thin layer of cartilage covering an epiphysis; reduces friction and acts as a shock absorber

oblique

type of fracture that occurs at an angle that is not 90 degrees

transverse

type of fracture that occurs straight across long axis of the bone

spiral

type of fracture that occurs when excessive twisting forces are applied to a bone

greenstick

type of fracture where a bone breaks incompletely, much in the way a twig breaks

impacted

type of fracture where broken bone ends are forced into each other

compound

type of fracture where the bone breaks through the skin; open fracture

simple

type of fracture where the bone does not penetrate the skin; closed fracture

comminuted

type of fracture where the bone is broken into many fragments

osteogenic cell

undifferentiated cell with high mitotic activity; the only bone cells that divide; they differentiate and develop into osteoblasts

mesenchymal cells

undifferentiated stem cells (not osteogenic cells)

articulation

where two bone surfaces meet (a joint)

articulations

where two bones meet; joints

epiphysis

wide section at each end of a long bone; filled with spongy bone and red marrow