Axial Bones Flashcards
Vertebrae
Body/Centrium
anterior region of each vertebra; weight bearing strucutre of almost all vertebra
Vertebrae
Lamina (2)
extend posteromedially from the posterior edge of each pedicle
Vertebrae
Vertebral arch/Neural arch
lamina + pedicle
posterior to the vertebral body; enclose vertebral foramen with body
Vertebrae
Vertebral canal
all stacked vertebral foramina form a superior to inferior directed canal that contains the spinal cord.
Vertebrae
Transverse process (2)
lateral projections on both sides of the vertebral arch
Vertebrae
Spinous process (1)
projects posteriorly from the left and right laminae; can be palpated through the skin of the back.
Vertebrae
Pedicle (2)
originate from posterolateral margins of the body
Vertebrae
Vertebral foramen
together the vertebral arch and body enclose this roughly circular opening
Vertebrae
Intervertebral foramen (only when stacked)
lateral openings between adjacent vertebrae; provide a horizontally directed passageway through which spinal nerves travel to other parts of the body
Vertebrae
Superior and inferior articular processes (4 total)
each vertebra has articular processes on both its superior and inferior surfaces that project from the junction between the pedicles and laminae.
inferior articular processes of each vertebra articulate with the superior articular processes of the vertebra immediately inferior to it.
Vertebrae
Intervertebral discs
pads of fibrocartilage that separate adjacent vertical bodies; composed of an outer ring of fibrocartilage, called the anulus fibrous, and an inner circular region, called nucleus pulposus
Characteristics of 7 Cervical Vertebrae
Relatively small,
kidney bean shaped,
no costal facets for ribs
transverse foramina present (except sometimes for C7)
transverse processes are small: C3-C6 often bifid (contain transverse foramina)
angle of articular facets: anteroinferior - posterosuperior
spinous process: slender (C2-C6 are often bifid)
C1 has no spinous process
Characteristics for Thoracic Vertebrae (12)
medium sized,
heart shaped,
costal facets for rib present on body and transverse processes,
transverse foramina not present
transverse processes are medium sized
Angle of Articular Facets: anteromedial and posterolateral
Spinous processes: long, most project inferiorly
Characteristics of Lumbar Vertebrae (5)
large, round/oval
costal facets for ribs not present,
no transverse foramina
Transverse processes: large, thick, and blunt
Angle of articular facets: lateral and medial
Spinous processes: short (thick and blunt), project posteriorly
Sacrum
an anteriorly curved, somewhat triangular bone that forms the posterior wall of the pelvic cavity,
composed of 5 fused sacral vertebrae
Auricular surface
on the lateral surface of the ala; marks the site of articulation with the ox coxae or pelvic girdle
Sacrum base
the bone’s broad superior surface
Ala
meaning “wing”; located on each lateral surface of the sacrum
Posterior sacral foramina
four pairs of opening for spinal nerves; located on the dorsal surface of the sacrum
Mid-sacral crest
a dorsal ridge formed by the fusion of the spinous processes of individual sacral vertebrae
Sacral promontary
anteriosuperior edge of the first sacral vertebra bulges anteriorly into the pelvic cavity
Apex
a narrow, pointed portion of the bone that projects inferiorly
Sacral spinal canal
where the vertebral canal becomes much narrower and continues through the sacrum
Anterior sacral foramina
permit the passage of nerves to the pelvic organs
Sacral hiatus
the inferior opening where the sacral canal terminates; represents an area where the laminae of the last sacral vertebra failed to fuse
Coccyx (4/5)
an attachment site for several ligaments and some muscles
Clavicle sternal end
median end; roughly pyramidal in shape and articulates with the manubrium of the sternum, forming the sternoclavicular joint.
Clavicle acromial end
lateral end; broad and flattened, articulates with the acromion of the scapula, fomring the acromioclavicular joint
True ribs (1-7)
at the anterior body wall, articulate individually to the sternum by separate cartilaginous extensions called costal cartilage
False ribs (8-12)
costal cartilages do not attach directly to the sternum; costal cartilage fuse to the costal cartilage of rib 7 and thus indirectly articulate with the sternum.
False and floating ribs (11 and 12)
the last two parts of false ribs are known as floating because they have no connection with the sternum
Costal cartilages
bars of hyeline cartilage that serve to prolong the ribs forward and contribute to the elasticity of the walls of the thorax; only found at anterior ends of ribs
Head
where the vertebral end of a typical rib articulates with the vertebral column
Neck
lies between the head and the tubercle
Articular tubercle/Costal tubercle
Articular: lower and more medial; presents a small oval surface for articulation with the end of the transverse process of the lower of the two vertebrae to which the head is connected
Costal: a rough elevation and affords attachment to the ligament of the tubercle
Costal angle
indicates the site where the tubular shaft begins curving anteriorly toward the sternum
Body/Shaft
flat and curved; internal surface has a groove for neurovascular supply of the thorax, protecting vessels and nerves from damage
Costal groove
groove along the inferior internal border of which marks the path of intercostal nerves and blood vessels to the thoracic wall
Manubrium
widest and most superior portion of the sternum; “handle” of the bony sword
Jugular notch/Suprasternal notch
shallow superior indentation between the clavicular notches
Sternal angle
horizontal ridge that may be pappated under the skin where the body and manubrium articulate
Clavicular notches
two notches that articulate the sternum with the left and right clavicles
Body/gladiolus
longest part of the sternum and forms its bulk; the “blade” of the bony sword
