Bones Flashcards
Hyoid
an irregular horseshoe like bone suspended from the tips of the styloid processes of the temporal bone by ligaments. (located anterior neck inferior to mandible)
Cranium
refers to all the bones in the skull, without the mandible.Divided into two parts, neurocranium for the brain, and splanchnocranium/viscerocranium for the face.
Neurocranium (8)
Paired: Parietal, Temporal
Unpaired: Frontal, Occipital, Sphenoid, Ethmoid
Splanchnocranium/Viscerocranium (14)
Paired: Maxilla, Zygomatic,, /nasal, Lacrimal, Palatine, Inferior nasal concha
Unpaired: Mandible, Vomer
Sutures
Coronal, sagittal, lambdoid
Mandible (4)
Head of condylar process, coronoid process, ramus, body
Mastoid process
“ear boob” located posterior to the external acoustic meatus, styloid process. Body landmark to reference when locating transverse processes of cervical vertebrae
Maxilla (4)
Lacrimal bone (eye socket), nasal bone (nose bridge), infraorbital foramen (cheek bone hole), alveolar process (upper lip area)
Typical vertebra (structural parts)
body, vertebral arch, articular processes, transverse processes, spinous process, pedicles, laminae, superior/inferior vertebral notch, vertebral foramen, intervertebral foramen
Vertebral column (breakdown)
Cervical: C1-C7 Atlas (C1) Axis (C2) Thoracic: T1-T12 Lumbar: L1-L5 Sacrum: Fused S1-G5 Coccyx
Cervical vertebrae
C1 (Atlas) C2 (Axis) C3-C7
Common features: small body, transverse foramen in transverse process, bifurcated spinous process
Atlas + Axis special features
Atlas: no body, lacks laminae and pedicles, HAS anterior and posterior arches. Lateral mass on either side, on superior/inferior of lateral mass there is articular surface for occipital condyles, and axis. Posterior surface of anterior arch has articular surface for the odontoid process of axis.
Axis: large odontoid process (dens axis) which is attached to superior surface of body. Process acts as a pivot (axis) and permits the rotation of the atlas on axis bone. (looks like meditating person)
Typical thoracic vertebrae
is concave forward and made up of 12 vertebrae together with their intervertebral discs. Have costal facets where ribs articulate (demi/semi/hemi), and on the transverse processes (transverse costal facet) for articulation with the tubercles of the ribs (T11 T12 have no facets on transverse processes)
Atypical thoracic vertebrae
T1- has an entire articular facet for the head of the first rib, semi facet for the upper half of the second rib.
T9- may have no semi facet below, only on the upper half
T10- full facets for 10th rib
T11+T12- full facets for 11+12th ribs, no facets on transverse processes
Lumbar vertebrae
convex anteriorly, body is kidney shaped, pedicles are strong, laminae are thick, transverse processes are long and slender, mammillary process is found at the posterior margin of the superior articular processes, the accessory process found on the posterior border of the transverse processes.
No facets or foramina in transverse processes
Fetal and adult vertebral curves
Fetus-one
Adult-four
Typical rib
long, twisted, flat bone with superior and inferior border (overhangs and forms costal groove, which accommodates intercostal vessels and nerve). Consists of : head, neck, tubercle, shaft, angle
Head has 2 semi facets, for articulation of ribs, as well as articular facets for transverse process of vertebra
Atypical rib
First rib- flat horizontally, tubercle on inner border “scalene tubercle” for insertion of the anterior scalene muscle. No angle, no costal groove, head has only one articular surface for T1.
Second rib- body is oriented in a plane between sagittal and horizontal planes, lacks costal groove.
10th- only has single articular facet on head
11th+12th- single articular fact on head, no neck no tubercle, 11 has slight angle and costal groove, 12 does not have them.
Sternum
Flat bone divided into 3 parts: manubrium, body, xiphoid process. Sterna angle (angle of louis): angle formed by junction of manubrium and body and forms cartilaginous joint, also called manubriosternal joint. Palpable, approximately level with 2nd pair of costal cartilages and between T4 and T5.
Rib cage
twelve pairs, R1-R7 true ribs with own costal cartilages, R8-R10 false ribs cartilages merge, R11-R12 free ribs no cartilages.
Sacrum and Coccyx
Sacrum: Spinous/articular/transverse processes fused to form a boney ridge called “sacral crests”. 4 pairs of sacral foramina. First sacral vertebra has 2 triangular flat surfaces called “sacral ala”
Coccyx: four vertebrae fused together articulated at teh apex of the sacrum
Hip (coxal) bone
3 Parts: ilium, ischium, pubis
