Question | Answer |
long bones | longer than they are wide, with a thick compact bone exterior |
short bones | almost equal in length and width and contain a thick interior of spongy bone covered by a thin veneer of compact bone |
flat bones | relatively flat, but may be curved and contain a thin, spongy bone interior covered by a thin veneer of compact bone |
irregular bones | do not easily fit into any of these categories, self explanatory |
sesamoid bones | small bones that develop in tendons for protection against wear and tear |
epiphyses | the enlarged proximal and distal ends of long bones |
diaphysis | the middle shaft area |
metaphyses | the areas in an adult bone where the epiphyses and diaphysis join |
epiphyseal plate | in a growing bone the metaphyses contain a layer of hyaline cartilage |
epiphyseal line | bone growth stops when the epiphyseal plate cartilage becomes ossified and forms a bony structure |
articular cartilage | composed of hyaline cartilage, covers both epiphyses |
periosteum | the bone exterior covered with a touch connective tissue membrane |
medullary cavity | the hollow center of the bony diaphysis |
endosteum | the medullary cavity is lined with a connective tissue membrane |
osteoblasts | bone formation, bone tissue repair |
osteoclasts | breaks down bone |
yellow marrow | a fatty substance found within the medullary cavity |
red marrow | found within the cavities of spongy bone and produces red blood cells |
nutrient artery | a large artery that enters compact bone near the middle of the diaphysis |
nutrient foramen | the foramen through which the nutrient artery enters |
compact bone | composed of repeating units of osteons with each unit having a central canal running longitudinally |
perforating canals | run horizontally in compact bone and connect with the central canal |
concentric lamellae | the main feature of each osteon, look similar to rings of a tree trunk cut in cross sections |
lacunae | dark areas that are found between concentric lamellae |
canaliculi | thin lines that connect the lacunae |
osteocytes | mature bone cells that reside in the lacunae |
interstitial lamellae | fills in the spaces between the osteons |
spongy bone | does not contain osteons but has trabeculae- lattice like network of thin bony columns lines with endosteum |
axial skeleton | 80 bones located along a vertical line, the longitudinal axis of the body- its bones support and protect the organs on the head, neck, and torso. |
appendicular skeleton | 126 bones that make up the upper limbs, lower limbs, and the bones of the girdles that attach the limbs to the axial skeleton. |
cranial bones | form a bony cavity that harbors and protects the brain and houses organs of hearing and equilibrium |
facial bones | provide the shape of the face, house the teeth, and provide attachments for all the muscles of facial expression |
parietal bones | superior lateral walls of cranial cavity |
temporal bones | inferior lateral walls of cranial cavity, house organs of inner ear |
frontal bone | anterior portion of cranial cavity |
occipital bone | posterior wall of cranial cavity |
sphenoid bone | floor of cranial cavity posterior to ethmoid |
ethmoid bone | floor and anterior wall of cranial cavity |
coronal suture | joins frontal and parietal bones |
sagittal | joins parietal bones |
lambdoid | joins both parietal bones with occipital bone |
squamous | join temporal and parietal bones |
maxillae | fused upper jaw bones |
zygomatic bones | cheek bones |
lacrimal bones | portion of orbit of eyes near nasal bones |
nasal bones | bridge of nose |
inferior nasal conchae | forms lateral walls of nasal cavity |
palatine bones | fused bones that form posterior part of hard palate |
mandible | lower jaw bone |
vomer | inferior portion of nasal septum |
supraorbital foramina | opening located above the orbit of each eye for supraorbital nerve |
supraorbital ridges or margins | thickening of frontal bone superior to orbit of each eye |
external auditory meatus | tube-like opening for the ear canal |
mastoid process | rounded projection posterior to external auditory meatus, attachment for muscles |
styloid process | thin projection on inferior skull surface, attachment for muscles and ligaments of tongue and neck |
zygomatic process | projections that articulates with the zygomatic bone |
mandibular fossa | depression in mandible for articulation with condylar process |
foramen lacerum | jagged opening filled with cartilage in a living person |
carotid foramen | foramen for internal carotid artery |
jugular foramen | foramen for jugular vein and cranial nerves |
stylomastoid foramen | opening for an artery and cranial nerve VII |
internal auditory meatus | opening for cranial nerve VII |
foramen magnum | opening through which spinal cord connects to lower brain |
hypoglossal foramina | openings for cranial nerves XII |
occipital condyles | rounded processes that articulate with the atlas |
cribriform plates | one on either side of crista galli |
crista galli | projection for attachment membranes covering brain |
olfactory foramina | tiny holes in cribriform plates for cranial nerve I |
perpendicular plate | forms superior part of nasal septum |
middle nasal conchae | scroll-like projections on each lateral wall of nasal cavity |
superior nasal conchae | scroll-like projections on each later wall of nasal cavity |
foramina ovale | openings for mandibular branch of cranial nerve V |
foramina rotundum | openings for maxillary branch of cranial nerve V |
sella turcica | bony projection that surrounds and protects pituitary gland |
greater and lesser wings | form anterior and lateral floor of cranial cavity |
optic foramina | openings for cranial nerve II |
inferior orbital fissures | openings for bloos vessels and nerves |
superior orbital fissures | openings for blood vessels and cranial nerves III, IV, V, VI |
pterygoid processes | wing-like projections on the base of the skill in the middle section of the sphenoid bone |
alveoli | tooth sockets |
palatine process | fused processes that form the anterior part of hard palate |
body | curved, anterior portion of mandible |
mental foramina | openings in chin for nerves and blood vessels |
rami | posterior branches, one on either side of the body of mandible |
condylar processes | rounded processes on rami that articulate with temporal bone at the mandibular fossa to form the TMJ |
coronoid processes | triangular projections of rami anterior to the condylar processes |
lacrimal fossa | canal that houses lacrimal sac; formed from the maxilla and lacrimal bone |
temporal process | projects posteriorly; temporal process of zygomatic bone and zygomatic process of temporal bone from the zygomatic arch |
paranasal sinuses | cavities lines with mucous membranes that are located near and have opening into the nasal cavities ex. ethmoid, frontal, maxillary, and sphenoid |
nasal septum | comprised fo 2 bones- vomer and perpendicular pate of the ethmoid bone |
hard palate | roof of the mouth- formed by the fusion of 4 bones: 2 palatine processes of the maxillary bones and 2 palatine bones |
fontanels | "soft spots" membranous sections composed of fibrous connective tisssue |
hyoid bone | U-shpaed bone not attached to axial skeleton |
vertebral column | flexible structure that can be bent, twisted, and rotated, especially in the cervical region. Consists of cervical, thoracic, and lumbar vertebrae and coccyx |
cervical | 7 bones |
lumbar | 12 bones |
sacral | 5 bones |
body- vertebrae | located anteriorly; the largest part of the vertebrae |
pedicle | attached to and extends posteriorly on either side of the body |
transverse process | extends laterally form each pedicle |
lamina | connects transverse processes to the spinous process |
spinous process | projects posteriorly from fused lamina |
vertebral arch | formed by the fusion of pedicles and laminae |
atlas | cervical vertebra 1- superior articular facets of the atlas articulate with the occipital condyles of the skull and allow the head to tilt up and down |
axis | C2- has a superior tooth-like protuberance called the dens or odontoid process |
vertebral foramen | large opening formed by the vertebral arch that protects the spinal cord |
superior and inferior articular processes | extend form the vertebra at the junction of the pedicle and lamina to articulate with a superior and inferior vertebra |
thoracic vertebra | medium sized body and usually long narrow spinous process that commonly slants inferiorly at a sharp angle |
lumbar vertebrae | the largest bodies to support more weight and thick, hatchet shaped spinous processes that extend horizontally |
intervertebral discs | found between the bodies of vertebrae from C2 to the sacrum |
sacrum | formed by the fusion of 5 sacral vertebrae and has a slightly curved, triangular shape, the broad superior portion os called the base and the two lateral winglike projections are called alae |
sacral foramina | provides exits for spinal nerves |
sacral canal | a continuation of the vertebral canal, located posterior to the body of the sacrum |
sacral hiatus | the inferior opening of the sacral canal |
superior articular processes | facets that articulate with the fifth lumbar vertebrae located on either side of the opening of the sacral canal |
auricular surfaces | the lateral surfaces of the sacrum- articulate with the iliac portion of the os coxa on each side |
sacroiliac joints | when the auricular surfaces articulate with the iliac portion of the os coxa on each side |
coccyx | tailbone |
thoracic cage | the bony cage that encircles the chest- composed of the sternum, ribs, costal cartilages, and thoracic vertebrae |
sternum | a narrow flat bone that is composed of three fused bones, the manubrium, the body of the sternum, and the xiphoid process |
manubrium | the superior portion of the sternum, has a concave superior surface called teh suprasternal notch or jugular notch |
sternal angle | between the body of the sternum and the manubrium, an important clinical landmark indicating attachment of the second rib |
xiphoid process | inferior portion of the sternum that is shaped like a small sword |
ribs | 12 pairs in both males and females- the first 7 are called true ribs because they have direct connection to costal cartilage, the last 5 rib pairs are called false ribs- ribs 11 and 12 are floaters |
head of rib | projects from the posterior part of the rib and articulates with demifacets on the bodies of thoracic vertebrae |
neck of rib | constricted part later to the head |
tubercle of rib | small, knob-like projection close to the neck that articulates with the facet of a transverse process |
body of rib | main part of rib |