unit 2 - osteology - mcb 245

long bones

bones greater in length than width; e.g. femur, humerus

short bones

bones length nearly equal to width; e.g. carpals and tarsals

flat bones

bones flat, thin surfaces, may be slightly curved; e.g. cranial bones

irregular bones

elongate, sometimes complex shapes; e.g. vertebrae

hemopoiesis

blood cell production

osteoprogenitor cells

stem cells that mature to become osteoblasts

osteoblasts

immature bone cells that secretes osteoid

osteocytes

mature bone cell that maintains the bone matrix

osteoclasts

multinucleate cells that secrete acids and enzymes to dissolve bone matrix

ossification

formation and development of bone

osteons

basic functional units of mature compact bone

trabeculae

highly porous form of bone tissue that is organized into a network of interconnected rods and plates which surround pores that are filled with bone marrow

condyle

articulating surface: large, smooth, rounded, oval structure

facet

articulating surface: small, flat, shallow surface

head

articulating surface: prominent, rounded epiphysis

trochlea

articulating surface: smooth, grooved, pulleylike process

alveolus

depression: deep pit or socket in the maxillae or mandible

fossa

depression: flattened or shallow depression

sulcus

depression: narrow groove

crest

projection: narrow, prominent, ridgelike projection

epicondyle

projection: projection adjacent to a condyle

line

projection: low ridge

process

projection: any marked bony prominence

ramus

projection: angular extension of a bone relative to the rest of the structure

spine

projection: pointed, slender process

trochanter

projection: massive, rough projection found only on the femur

tubercle

projection: small, round projection

tuberosity

projection: large, rough projection

canal

openings/spaces: passageway through a bone

fissure

openings/spaces: narrow, slit-like opening through a bone

foramen

openings/spaces: rounded passageway through a bone

meatus

openings/spaces: passageway through a bone

sinus

openings/spaces: cavity or hollow space in a bone

axial skeleton

composed of bones that form the longitudinal axis of the body from the skull to the end of the vertebral column

appendicular skeleton

composed of bones that make up the limbs and girdles which attach limbs to the axial skeleton

bone markings

bumps, holes, and ridges on bones where muscles, tendons, and ligaments are attached and where blood vessels and verves pass through

articulation

a joint; where 2 bones meet

fontanels

spaces between bones in an infant skull

canaliculi

tiny canals that radiate outward from the Haversian canal to lacunae to supply the bone cells with nutrients

diaphysis

shaft of a long bone; composed of compact bone

epiphysis

end of a long bone; composed mostly of spongey bone

epiphyseal line

marking left on the bone from growth at the epiphyseal plate

remodeling

process of breaking down and reforming bone that occurs throughout life to maintain proportion and strength as well as healthy calcium levels

fracture

broken bone

rickets

soft bones caused by lack of vitamin D, calcium, or phosphorus

vertebral body

thick anterior weight-bearing structure (part of vertebrae)

vertebral arch

posterior to body (part of vertebrae)

vertebral foramen

opening enclosed by body with vertebral arch

vertebral canal

formed by stacked vertebral foramina, contains the spinal cord

pedicles

originate from posterolateral margins of body (part of vertebrae)

laminae

extend posteromedially from posterior edge of pedicle

spinous process

projects posteriorly from laminae junction

transverse process

lateral projections on both sides of vertebral arch

superior and inferior articular processes

originate at junction between pedicles and laminae, have smooth surface articular facet-articulate with vertebra either above or below

intervertebral discs

pads of fibrocartilage separating vertebral bodies, shock absorbers, allows vertebral column to bend

true ribs

ribs 1-7, connect individually to the sternum by costal cartilages

false ribs

ribs 8-12, costal cartilages not attached directly to the sternum

pectoral

refers to the shoulder region

pelvic

refers to the hip region

clavicle

is an elongated, S-shaped bone which extends between the manubrium of the sternum and the acromion of the scapula

scapula

shoulder blade

humerus

longest and largest upper limb bone

ulna

longer, medially placed bone of the forearm

carpals

wrist bones; allow multiple movements at wrist; arranged in 2 rows of 4 bones each

ilium

largest of 3 coxal bones; forms superior region of the os coxae

femur

longest, heaviest, strongest bone in body

patella

kneecap, large, triangular sesamoid bone

fibula

long, lateral, non-weight-bearing bone of the leg

axial skeleton

appendicular skeleton

ossification

the formation and development of bone connective tissue

endochondral ossification

- process that begins with a hyaline cartilage model

- produces most bones of the skeleton

intramembranous ossification

- bone growth within a membrane (sheet of mesenchymal connective tissue)

- produces flat bones of the skull, some facial bones, the mandible, and the central part of the clavicle

- most ossification occurs during embryological development

osteon

basic functional and structural unit of mature compact bone

central canal

channel at center of osteon that contains blood vessels and nerves

concentric lamellae

bone connective tissue made up of collagen fibers; concentric circles around central canal

osteocytes

mature bone cells found between lacuna to maintain bone matrix

lacuna (with osteocyte)

A

osteon

central canal

concentric lamellae

canaliculi

compact bone

spongy bone

trabeculae

parallel lamellae

occipital bone

occipital bone

parietal bone

parietal bones

frontal bone

frontal bone

temporal bone

temporal bone

sphenoid

sphenoid

sphenoid

ethmoid

ethmoid

ethmoid