The Axial Skeleton Flashcards
what does the axial skeleton include?
skull, vertebral column, ribs, and sternum
What does the skull and vertebral column protect?
the CNS, brain, and spinal cord
what else does the vertebral column do besides protect the spinal cord?
it is important to posture and locomotion because it has many attachments to muscles
What do the ribs and sternum do?
protect the organs of the thoracic cavity and through their movements, play an important role in ventilating the lungs
intervertebral discs
found in between the ~33 vertebrae of the vertebral column
name the 5 regions of vertebrae
cervical, thoracic, lumbar, sacral, coccygeal
which two vertebrae regions curve like a D?
thoracic and sacral
body of a vertebrae
the weight bearing region of the vertebra. they become larger in the lower regions of the vertebral column and bear more of the body’s weight
vertebral foramen of a vertebae
location of the spinal cord
spinous and transverse processes of a vertebrae
sites of muscle attachments
articular processes of a vertebra
form joints with articular processes of adjacent vertebrae. restrict movement of vertebral column
intervertebral foramina
above and below the pedicles of each vertebra a notch is carved out that allows for the passage of a spinal nerve
atlas
first vertebrae. it has no vertebral body and serves to articulate with the skull. movement between the skull and C1 is in the sagittal plan (nod)
axis
C2, it has a projection called the dens that fits into the large vertebral foramen of C1.
What does the dens do?
prevent C1 from slipping posteriorly and allows rotation of head (shake)
vertebra prominens
c& because of its long spinous process
what is the most distinguishing feature of the thoracic vertebrae?
their articulation with ribs
where are the largest vertebral bodies found?
on the lumbar vertebrae; they support a large amount of my body’s weight (no articulation with ribs)…they have strong stout transverse and sponous processes
median sacral crest
the spinous processes of the sacral vertebral bodies fuse together
alae
the transverse processes of the sacral vertebrae fuse together to form wings
sacral canal
where the spinal nerves travel through the vertebral canal
where do the spinal nerve branches exit in the sacrum?
through the 5 pairs of anterior and posterior sacral foramina
coccyx
3-5 tail vertebrae fuse to form the tailbone
name the parts of the sternum
manubrium (top), body, and xiphoid process (tip)
head of a rib
where the articulation with the costal facet of a thoracic vertebral body occurs
neck of a rib
the head tapers off to this. where a tubercle is present
tubercle of a rib
articulates with the costal facet of a thoracic vertebra’s transverse process
costal cartilage
where the ribs terminate. spans the gap to the sternum
true ribs v false ribs
true ribs articulate directly with the sternum. false ribs connect to other costal cartilage or just float there (not attached to sternum)
cranial sutures
form where adjacent bones fuse during development, only some are visible in adults
cribiform plate
in the cranial cavity; part of the ethmoid bone that allows the passage of CN I from the nasal cavity to the olfactory bulb
sphenoid bone
in the cranial cavity; sitting at the center of the skull, it houses the pituitary gland and the sphenoid sinus, forms the pterygoi processes for attachment of jaw muscles, and borders the orbit, cranial, and nasal cavities. it is visible from nearly any internal or external view of the skull
sell turcica
in the cranial cavity; the part of the sphenoid bone that houses the pituitary gland. “turkish saddle”
foramen magnum
in the cranial cavity; the brainstem exits the skull at this largest foramen
internal acoustic meatus
in the cranial cavity; a passage for CN VIII from the inner ear to the brain
what is housed in the orbit?
the eye, extranocular muscles, and associated neurovascular structures
which six bones form the orbit?
frontal, zygomatic, maxillary, lacrimal, ethmoid, and sphenoid bone
the roof of the oral cavity’s hard palate is formed by which two bones?
maxillary and palatine bones
what separates the two nasal cavities?
nasal septum
nasal conchae
bony spirals that project into the nasal cavities from their lateral walls. as air passes through and over these coils during ventilation, it is humidified and warmed by the ample mucous membranes
parnasal sinuses
small cavities within the bones surrounding the nasal cavities. air-filled and lines with mucous membranes, the sinuses are connected to the nasal cavities
hyoid bone
horseshoe-shaped bone that floats below the mandible, held together with ligamentous attachments to the styloid process of the skull and to the larynx. also has many other muscle attachments including some of the tongue
its purpose is to allow for muscular control of pharyngeal, laryngeal, and lingual processes
