Bone Practical Lab

Cranium

encloses the brain

Frontal bone

anterior skull; forms the forehead, roof of orbits and nasal cavity; contains the frontal paranasal sinuses and develops as 2 bones which then fuse

Parietal bone

posterior to the frontal bone; one on each side of the skull

Temporal bone

inferior to parietal bones & posterior to sphenoid; forms parts of the sides and base of the

cranium; articulates with the mandible; houses inner and middle ear; contains numerous foramina

External auditory meatus

tube-like passageway to the ear

Mastoid process

posteroinferior to external auditory meatus; the bump posterior to your ear lobe; for

attachment of neck muscles; contains air spaces which may become infected

(mastoiditis)

Styloid process

long pointed process anteroinferior to external auditory meatus; attachment point for

muscles and ligaments of the pharynx and tongue

Occipital bone

forms the inferior portion of posterior skull and most of the base of the skull

Foramen magnum

large opening at base; connection point of brainstem & spinal cord

Occipital condyles

lateral to foramen magnum; articulates with cervical vertebra #1 (C1 or atlas) and allows you to nod "yes"

External occipital protuberance

at the midline posterior to the foramen magnum

Sutures

an immovable (synarthrotic) joint where irregular edges of bones interlock or overlap

lambdoidal suture

separates the occipital & parietal bones

squamosal suture

separates the temporal & parietal bones

sagittal suture

separates the L & R parietal bones

Coronal suture

separates the frontal & parietal bones

Sutural (Wormian) bones

small bones located within sutures; variable number (not occiptial)

Sphenoid bone

an irregular bone anterior to the temporal bone;forms the middle floor of the cranial cavity and

part of the lateral orbits; contains numerous foramina for some cranial nerves and blood vessels;

Sphenoidal sinuses

has 2 paranasal sinuses, in the sphenoid bone

Sella turcica

on cranial floor; houses/protects the pituitary gland

Greater wing (Sphenoid)

large lateral masses of the sphenoid; like a butterfly

Lesser wing (Sphenoid)

smaller and more anterior portion of the sphenoid

Ethmoid bone

an irregular bone anterior to the sphenoid; forms part of orbits, roof of nasal cavity, upper nasal septum

Ethmoid sinuses

has 2 paranasal sinuses, in ethmoid bone

Crista galli

superior vertical projection which serves as attachment point for the outer membrane of the brain

Cribriform plate

on either side of the crista galli;

Olfactory foramina

the passageways for olfactory (smell) nerves

Perpendicular plate (Ethmoid)

inferior bony plate which forms the superior

Nasal septum

bone & cartilage which separates the nasal cavity into R&L compartments

Superior nasal conchae (and Medial nasal conchae)

delicate scroll-like bones which facilitate air flow and support the

nasal mucous membranes note

Inferior nasal conchae

separate bones

fontanels

(fetal skull) areas of embryonic dense CT ("soft spots") which allow for skull compression during parturition

and for brain development; fully ossified by age 2

Frontal fontanels (anterior fontanels)

at the juncture of the frontal and parietal bones; the largest

Occipital fontanels (posterior fontanels)

at the juncture of the occipital and parietal bones

Mastoid fontanels

near the mastoid process

Sphenoid fontanels

near the sphenoid bone

Facial bones

form the face and jaw

Maxillae

the upper jaw; forms the floor of the orbits, sides and floor of the nasal cavity and the anterior hard palate

(roof of mouth); alveolar processes hold the upper teeth;

Maxillary sinus

sizing of sinus is large and it is in the maxillae bone

Infraorbital foramen

nerve and blood vessel passageway below the orbit

Palatine process

forms the anterior hard palate

Palatines

irregular bone which forms the posterior hard palate & part of the orbit & nasal cavity

Zygomatic bone

cheekbones; forms cheek and parts of the orbit

Zygomatic arch

forms from the zygomatic temporal process and the zygomatic process of the temporal bone

(i.e. is 2 bones); palpable anterior to your ear; for attachment of chewing muscles

Vomer

forms the lower part of nasal septum (along with the ethmoid/perpendicular plate

Lacrimal

small bones in medial orbit wall between ethmoid and maxilla; houses duct which carries tears (lacrimal =

tear) from the eye to the nasal cavity

Nasal bone

form the bridge of the nose

Mandible

the lower jaw bone, the only movable skull bone

Body (Mandible)

horizontal horse-shoe shaped portion which forms the chin

Ramus

vertical extension extending from the body (ramus = bar)

Mandibular condyle

articulates with the temporal bone

Temporomandibular joint

the mandibular condyle articulate the temporal bone to form temporomandicular joint

Coronoid process (Mandible)

anterior process, for attachment of a chewing muscle

Mental foramen

In middle of the body of the mandible; for blood vessels and innervation of teeth

Alveolar processes

sockets which hold lower teeth in place (same in maxilla)

Hyoid

located in the neck (not part of skull) between the mandible and larynx; attachment point for tongue and

swallowing muscles;

the only bone that does not articulate

Thoracic cage

encloses and protects the thoracic viscera

Sternum

the "breast bone" which forms the anterior thoracic cage

Manubrium

superior portion, like the knot of a tie; articulates with the clavicle & rib 1

Body (sternum)

large middle portion; articulates with ribs

Xiphoid process

small inferior portion; attachment point for some abdominal muscles

Ribs

(12 pairs) are flat bones

True ribs

1-7 which articulate directly with sternum (via costal cartilage)

Costal cartilage

False ribs (5 pairs)

ribs 8-12 which do not articulate directly with the sternum

False ribs (ribs 8-10)

articulate with the sternum via the costal cartilage of rib 7

False ribs (ribs 11-12)

do not articulate with the sternum at all (are called floating ribs)

Head (Ribs)

articulate with the body of a vertebrae

Tubercle (Ribs)

articulates with a transverse process of a vertebrae

Vertebral column

the "backbone"

(33; including sacrum & coccyx); most C, T & L are separated by intervertebral disks

Cervical

form the neck and are very flexible; have transverse foramina; C1-C6 have forked transverse processes

Vertebral prominens

Part of cervical bone

Atlas

C1; has no spine or body; large facet for articulation with occipital condyles

Axis

C2; has an odontoid process (dens), no intervertebral disk between C1 & C2

Odontoid process (dens)

which forms a pivot joint with the atlas;

allows lateral rotation of head

Thoracic

have facets on transverse processes & body for articulation with ribs; relatively inflexible

Lumbar

have large strong bodies which support the weight of the body; more flexible than T vertebrae; area where most disk herniations occur;

Intervertebral foramina

openings on the lateral side of the vertebral column between vertebrae; passage for spinal nerves

Body (Vertebrae)

thick anterior portion; contacts intervertebral disks

Vertebral foramen

passageway for spinal cord; bounded by body, pedicle and lamina

Pedicle

forms sides of the vertebral foramen, between body & transverse proces

Lamina

plate-like area between pedicle and spinous process

Transverse process

projects laterally and posteriorly; for muscle attachment

Spinous process

projects posteriorly from the medial portion; for muscle attachment

Superior articular process

paired projections lateral to the vertebral foramen on the superior aspect of the

vertebra; articulates with the inferior articular process of the adjacent superior vertebrae (is a synovial joint)

Inferior articular process

similar to the above but on the inferior aspect of vertebrae

Transverse foramen (Vertebrae)

(C only) passageway for vertebral artery & vein (goes to the brain)

Facet (rib tubercle)

(T only) on transverse process; articulates with rib tubercle

Facet (head of rib)

(T only) two on each side of a vertebra (facet or demifacet); articulates with head of rib facets are on 1, 10-12; demifacets (articulate w/ 2 ribs) are on 2-9

Sacrum

5 fused vertebrae at the base of the vertebral column; articulates with pelvic girdle/ilium and thus connects

to appendicular skeleton

Sacral foramina

four pairs; for passage of nerves and blood vessels

Sacral canal

central hollow area which is an extension of the vertebral foramina

Sacral promontory

anterior border of S1, an anatomical landmark

Coccyx

4 fused vertebrae; the "tailbone"

Pectoral girdle

The shoulder girdle; supports and connects arms to the thoracic cage

Clavicle

The "collar bone"; extends from the acromion of the scapula to the sternum

Sternal end

medial round & flat end

Acromial end

lateral end which articulates with acromion of the scapula

Scapula

there is two right and left pairs

Right scapula