Axial Skeleton Flashcards
-protects brain
-provides attachment sites for head and neck muscles
-houses major sensory organs for vision, hearing, balance, taste, and smell
- 29 total bones
-22 skull bones
skull
-supports trunk
-protects the spinal cord
-provides attachment sites for ribs and muscles of neck and back
-infants have 33 separate vertebrae
-adults have 26 because 9 fuse to form 2 composite bones
vertebral column
-protective structure around organs of the throacic cavity
-sternum and paired ribs 25 bones total
-costal cartilages
-thoracic vertebrae
thoracic cage
-8 bones that form cranium
-connected by immovable articulations called sutured
cranial bones
cranium
-cranial vault
-cranial base
superior, lateral, and posterior walls of skull
cranial vault
bottom of the skull
cranial base
located medially at level of intervertebral disc between T2 and T3
suprasternal notch
clavicle forms a joint with manubrium
clavicular notch
landmark for finding rip 2 when using a stethoscope
sternal angle
heart sits on diaphragm
xiphisternal joint
What are the true rips numbered?
1-7
What are the false ribs numbered
8-12
What are the floating ribs numbered
11-12
-named after greek god who carried the world on his shoulders
-only one that articulates with skull
-has no spinous process
-has no vertebral body
-has anterior arches that meet at anterior tubercle
-has posterior arches that meet at posterior tubercle
-has lateral masses on either side
Atlas (C1)
-peg-like dens (odontoid process) project superiorly to body
-articulates with enlarged vertebral foramen of the atlas
Axis (C2)
-receive occipital condyles of occipital bone of skull
- inferior articular facets articulate with axis
superior articular facets
-between C1 and C2
-no intervertebral disc between atlas and axis
atlantoaxial joint
-spinous process is larger than other cervical vertebrae
-not bifid
-vertebra prominens
C7
-heart-shaped body bearing 4 small facets where ribs articulate
- a spinous process that points sharply inferiorly
-a circular vertebral foramen
thoracic vertebrae
-large sizes and weights
-wide kidney-shaped bodies
-blunt, hatchet-shaped spinous processes
-triangular vertebral foramina
Lumbar vertebrae
-prominent bulge on anterosuperior margin
-important anatomical landmark in females during female exams/labor and delivery
-alae
sacral promontory
-marks sites of vertebral fusion
transverse lines
-composed of 3-5 fused vertebrae
-horn-like projections (coccygeal cornu)
-offers slight support to pelvic organs
-serves as point of attachment for muscles of pelvic floor
coccyx
-opening that lies between body and vertebral arch
-adjacent vertebral foramina form vertebral canal
-houses spinal cord
vertebral foramen
-inferior to mandible
-C-shaped
-does not articulate with any other bone
-serves as a moveable base for tongue
-serves as attachment site for neck muscles that raise and lower larynx during swallowing and speech
hyoid bone
-paired; irregularly shaped
-closes around 12 months
mastoid fontanels
paired; small, irregularly shaped
-closes around 3 months
sphenoid fontanels
small, triangular
-closes around 2 months post-birth
posterior fontanel
-largest fontanel; diamond-shaped
-closes 18-24 months post-birth
anterior fontanel
divided left and right frontal bones
-closes around 3-9 months
frontal suture
what is the function of paranasal sinuses
-lighten skull
-add resonance to the voice
-warm, moisten, and clean inhaled air
upright branch of mandible that serves as attachment site for a muscle that closes jaw
mandibular ramus
area at which body meets ramus
mandibular angle
rounded projection that articulates with mandibular fossa of temporal bone
mandibular condyle
insertion site for a muscle that closes mouth
coronoid process
indentation between coronoid process and mandibular condyle
mandibular notch
-forms upper jawbone
-keystone bones of the face
-articulate with all other bones except mandible
maxillae
-superior border of the mandibular body
-contains tooth sockets
alveolar process
openings in mandible that serve as passageways of nerves and blood vessels
mental foramina
most deeply situated bone of skull
ethmoid bone
-superior projection in the midline of ethmoid bone
-attached to the brain by connective tissue wrappings
crista galli
-bony plates studded with olfactory foramina
-serve as passageways for fibers of olfactory cranial nerves
cribriform plates
forms superior portion of nasal septum
perpendicular plate
-thin bone scrolls projecting into the nasal cavity on either side of the perpendicular plate
-creates air turbulence that slows air movement
superior and middle nasal conchae
-small transverse ridges on either side of the external occipital protuberance
-created by neck muscle attachments
superior and inferior nuchal lines`
-bat-shaped bone located posterior to frontal bone
-articulated with every other cranial bone
-keystone bone of cranium
sphenoid bone
-project laterally from central body of sphenoid bone
-form part of floor of middle cranial fossa
greater wings
horn-shaped projection that form part of floor of anterior cranial fossa
lesser wings
-project inferiorly form greater wings
-attachment site for muscles
pterygoid processes
forms posterior part and most of base of cranium
occipital bone
large opening on inferior surface of skull where brain and spinal cord meet
foramen magnum
rounded projections that articulate with 1st cervical vertebrae (atlas) to form atlantooccipital joint
occipital condyles
opening where a cranial nerve passes
hypoglossal canals
ridge of bone that extends posteriorly form foramen magnum and ends at external occipital protuberance
external occipital crest
-small midline bump at end of external occipital crest
-occurs at the junction between base and posterior wall of skull
external occipital protuberance
