Axial Skeleton Flashcards
What are the bones of the cranium?
PEST OF 6 or 8… Parietal, Ethmoid, Sphenoid, Temporal, Occipital, Frontal
Squama of Frontal Bone
Flat region forming the forehead
Supraorbital margin
Upper edge of the eye socket (frontal)
Supraorbital Foramen
Opening in center of supraorbital margin (frontal) contains nerve that sends sensory info from superior region of face
Zygomatic process of frontal bone
articulates with frontal process of zygomatic bone
Parietal Bones
2 bones on superior lateral walls of cranium
Grooves for meningeal vessels
Depressions on deep surface that contour to the blood vessels in the membranes surrounding the brain
Parietal eminence
Central region on exterior surface of parietal bones with the greatest convex curvature
What are the four major sutures?
Coronal, Sagittal, squamous, and lambdoid
Coronal suture
between frontal and parietal
Sagittal suture
between two parietal
Squamous suture
between temporal and parietal
lambdoid suture
between occipital and parietal
Occipital Bone
large flat convex bone makes up posterior wall and base of cranium
Foramen Magnum
large opening on base of cranium, contains medulla oblongata that attaches to spinal cord
Occipital condyles
Smooth extensions lateral to foramen magnum that articulate with c1 or atlas
Hypoglossal Canals
lateral to foramen magnum contains a cranial nerve that excites muscles of the tongue
External occipital crest, protuberance, and nuchal lines
on exterior of occipital bone, point of attachement for muscles and ligaments that extend and stabilize the neck
Fossa for cerebrum
smooth convex deep surface contours to occipital lobe of cerebrum
Fossa for cerebellum
smooth convex deep surface contours to cerebellum
Jugular notch
forms the medial side of jugular foramen that is origin of jugular vein draining blood from the brain
Temporal bone
2 medium sized irregular shaped bones forming the inferior lateral walls of the cranium
Squamous part of temporal bone
Exterior flat part that forms the squamous suture
Petrous part of temporal bone
interior part that has a complex shape and contains middle ear w auditory ossicles and inner ear with cochlea, vestibule and semicircular canals
Zygomatic process of temporal bone
articulates with the temporal process of zygomatic bone
Mandibular fossa
articulates w condylar process of mandible to form only mobile skull joint
External acoustic/auditory meatus
Opening for air in external ear vibrate the tympanic membrane and ossicles of the middle ear
Internal acoustic/auditory meatus
vestibular cochlear nerve travels from inner ear
Mastoid process
insertion for sternocleidomastoid muscle that flex and rotates neck
Stylomastoid foramen
located between styloid and mastoid processes, opening that contains facial nerve
Styloid process
origin of styloglossus and stylohyoid muscles
Carotid foramen or canal
Contains internal carotid artery supplying blood to the brain, located medial lateral to styloid process
Sphenoid bone
medium sized irregular shaped bone forms the anterior floor of cranium and articulates with all seven of the other cranial bones, contains air filled sinuses that connect to nasal cavity
Pterygoid processes
Inferior extensions that provide attachment for pterygoid jaw muscles
Greater wings
Majority of sphenoid bone extending lateral from the central body and contains foramen spinosum, foramen ovale, and foramen rotundum
Foramen spinosum
furthest posterior and lateral opening in greater wing, small rounded opening that contains meningeal vessels
Foramen ovale
oval shaped opening on posterior of greater wing contains mandibular branch of trigeminal nerve
Foramen rotundum
round opening on the medial to foramen ovale in the greater wing contains maxillary branch of trigeminal nerve
Lesser wing
broad regions on anterior superior to greater wings, contains optic foramen
Optic foramen
contains optic nerve that carries vision from the eyes
Superior orbital fissure
large elongated opening between the lesser and greater wing, contains several nerves traveling to and from eyes
Sella Turcica
Cup shaped depression posterior and medial to lesser wings that protects the pituitary gland
Ethmoid bone
small irregular bone that forms the roof of nasal cavity, contains air filled sinuses that connect with nasal cavity
Crista galli
“rooster comb” anterior attachment of falx cerebri (meninges that stabilize brain)
Cribiform plate
Numerous small foramina lateral to the crista galli that contain branches of the olfactory nerve
Perpendicular plate
forms superior portion of nasal septum dividing the nasal cavity into left and right
Nasal concha
superior and middle nasal concha are scroll shaped extensions of the ethmoid that project into the nasal cavity lateral to the perpendicular plate and produce turbulence that helps warm and humidify incoming air
Anterior cranial fossa
formed from frontal, ethmoid and sphenoid bones
Middle cranial fossa
formed from sphenoid, temporal and parietal bones
Posterior cranial fossa
formed from the occipital, temporal and parietal bones
What is a fontanelle?
fibrous CT between cranial bones of an infant
Anterior fontanelle
Junction of sagittal and coronal sutures
Posterior fontanelle
junction of lambdoid and sagittal sutures
Sphenoidal fontanelle
junction of squamous and coronal sutures
Mastoid fontanelle
junction of squamous and lambdoid sutures
What are the facial bones?
Virgil Can Not Make My Pet Zebra Laugh…Vomer, Concha, Nasal, Mandible, Maxilla, Palatine, Zygomatic, Lacrimal.
Vomer
Small flat bone shape resembles a plow, forms the inferior portion of nasal septum
Nasal bones
2 small flat bones forming the bridge of the nose
Maxilla
2 irregular shaped bones, form upper jaw and medial margin of orbit, contains air filled sinuses that connect to nasal cavity
Alveolar process
ridges around teeth
Mandible
Irregular bone forming the lower jaw, body contains alveolar process and mental foramen
Mental foramen
Opening on the anterior surface of mandible that contains mandibular branch of trigeminal nerve
Ramus
Process that projects superior from mandibular angle
Condylar process
articulates with mandibular fossa to form only mobile skull joint
Coronoid process
insertion for temporalis muscle that closes jaw
Mandibular notch
smooth concave curve at end of ramus between condylar and coronoid processes
Mandibular foramen
opening on medial surface of ramus contains a division of mandibular branch of trigeminal nerve carrying sensory information from lower jaw (site for novacain injections)
Palatine bones
2 small irregular bones that resemble the letter L with a horizontal plate that form the posterior 1/3 of hard palate
Zygomatic bones
2 medium sized irregular bones that form the cheeks, located lateral to the maxillae and anterior to temporal and sphenoid bones
Lacrimal bones
2 smallest bones of the face located in the medial orbits
Lacrimal groove
forms nasolacrimal duct draining tears
Hyoid
small irregular horseshoe shape bone located inferior to mandible, has no bony joints
List the bones that form the orbital complex (7)
Frontal, Zygomatic, Maxilla, Palatine, Lacrimal, Ethmoid and Sphenoid
How many bones make up the vertebral column?
26…7 cervical, 12 thoracic, 5 lumbar, 1 sacrum, 1 coccyx
Primary curve
Present at birth, thoracic and sacral regions
Secondary curve
Develop w upright posture, cervical and lumbar regions
Scoliosis
lateral curve
Kyphosis
exaggerated thoracic curve “hump back”
Lordosis
exaggerated lumbar curve “sway back”
Characteristics of a typical vertebrae
Body, Pedicles, Lamina, spinous process, transverse processes, superior and inferior articular processes, intervertebral foramen
Intervertebral discs
Pad preventing contact between adjacent vertebral bodies, annulus fibrosus is outer ring of fibrocartilage, nucleus pulposus is jelly like core of loose CT
Cervical vertebrae
C1 to C7, C1 is atlas, C2 is axis, split tip spinous process, transverse formamina in transverse processes, C7 is vertebra prominens and does not have split tip spinous process C7 is similar to thoracic vertebrae but has no costal facets
Thoracic vertebrae
T1 to T12, costal facets on the body and transverse processes articulate w the ribs, long slender spinous processes that point inferior
Lumbar vertebrae
L1 to L5, large oval shaped body, small vertebral foramen, blunt square shaped spinous process
Sacrum
Large irregular bone forming the posterior wall of the pelvic cavity, formed from the fusion of 5 vertebrae, base is wide superior end that articulates w L5, apex is inferior end that articulates w coccyx, canal contains spinal nerves that extend from spinal cord through the vertebral foramen and exit throughj the 4 pairs of sacral foramina, median sacral crest is ridge on the posterior down midline resulting from fused spinous processes
Coccyx
“tail” bone made of 3-5 small vertebrae that fused together late in life
Sternum
large flat bone along midline on anterior thorax
Manubrium
broad superior part of sternum
jugular notch
curved superior edge on midline between clavicles
Body of sternum
large middle portion
Xyphoid process
“sword like” inferior pointed tip of sternum, originally made up of cartilage but gradually ossifies during adult life
Ribs
24 medium sized flat bones extending lateral and anterior from the thoracic vertebrae, superior ten curve medial at the anterior of the thorax to form cartilaginous articulations with sternum (costal cartilage)
True ribs
numbered 1-7 attach to sternum directly through distinct costal cartilages
False ribs
8-10 attach to costal cartilage of rib 7
Floating ribs
11 & 12 have no costal cartilage
Features of a rib
Head, Tubercle, Neck, Angle, Costal groove
Head of rib
articulates w the costal facets or vertebral body
Tubercle of rib
articulates with the costal facets on the transverse processes of thoracic vertebrae
Neck of rib
region between head and tubercle
Angle of rib
point of greatest curvature
Costal groove
long narrow depression on the inferior surface that contains costal nerves and blood vessels
