axial skeleton Flashcards
axial skeleton
-skull
-vertebral column
-thoracic cage
general functions of the axial skeleton
-protect organs
-house special senses
-muscle attachment
-hematopoiesis
skull is composed of
cranial and facial bones
number of cranial bones
8
unpaired cranial bone
-ethmoid
-frontal
-occipital
-sphenoid
paired cranial bones
-parietal
-temporal
number of facial bones
14
facial bones have no
brain contact
unpaired facial bones
-vomer
-mandible
paired facial bones
-maxillae
-nasal
-lacrimal
-zygomatic
-palatine
-inferior nasal conchae bones
many bones have passageways for
blood vessels and nerves
sutures
immovable joints
four major sutures of the skull
-sagittal
-coronal
-lambdoid
-squamous
it is common for individuals to have what kind of sutural bones
small sutural bones
what do sutures start doing during adulthood
disappear as bones fuse
calvaria
-skull cap
-parietal bones, and parts of frontal and occipital bones
base of cranium
-floor
-where the brain lays
-parts of ethmoid, sphenoid, occipital and temporal bones
three cranial fossae in the floor of the cranial cavity
-anterior cranial fossa
-middle cranial fossa
-posterior cranial fossa
functions of the face bones
-give shape to the face
-form part of the orbital and nasal cavities
-support teeth
-serve as attachment sites for muscles of expression and chewing
paranasal sinuses
cavities within the skull
function of paranasal sinuses
lighten the skull
orbits
bony cavities in the skull that hold and protect the eyes
orbits consist of
-multiple bones
-muscles that move eyes
auditory ossicles
three tiny bones in petrous part of each temporal bone
function of auditory ossicles
help with hearing
three auditory ossicles
-malleus
-incus
-stapes
hyoid bone
located between the mandible and larynx
hyoid bone does not articulate with
any other bone
function of hyoid bone
attachment site for tongue and muscles of larynx used in swallowing
fontanelles
flexible areas of dense regular connective tissue used to connect infant cranial bones
major fontanelles
-mastoid
-sphenoidal
-posterior
-anterior
vertebral column is composed of
26 bones
number of individual vertebrae in the vertebral column
24
number of cervical vertebrae
7 (C1-C7)
number of thoracic vertebrae
12 (T1-T12)
number of lumbar vertebrae
5 (L1-L5)
two inferior bones of the vertebral column that are fusions of several vertebrae
sacrum and coccyx
sacrum
5 fused vertebrae
coccyx
-3-4 fused vertebrae
-tail bone
functions of vertebral column
-vertical support of body
-stable support for appendicular skeleton
-protect spinal cord
-passageway for spinal nerves
four spinal curvatures present in adults
-cervical
-thoracic
-lumbar
-sacral
scoliosis
abnormal lateral curvature
kyphosis
-exaggerated thoracic curvature
-posterior
-common in people with osteoporosis
lordosis
-exaggerated lumbar curvature
-anterior
-common in pregnant women
intervertebral discs
-pads in-between vertebrae that help absorb compressive forces
-allow vertebral column to bend
nucleus pulposus
deeper, jelly-like center
anulus fibrosus
ring surrounding nucleus pulposus
herniated/slipped disc
-anulus fibrosus ruptures, allowing the nucleus pulposus to protrude
-puts pressure on spinal nerve roots, causing pain
-usually caused by heavy lifting
treatments of herniated/slipped disc
-heat
-medication
-physical therapy
-surgery
most vertebrae have these features
-body
-vertebral arch
-vertebral foramen
-pedicles
-laminae
-intervertebral foramina
-spinous process
-transverse process
-superior articular process/facet
-inferior articular process/facet
body
weight bearing region
vertebral arch
attaches to body from vertebral foramen
pedicles
-feet of the arch
-connect arch to body
laminae
-posterior extensions of the arch
-close to spinous process
spinous process
projects posteriorly
transverse process
projects laterally
superior articular process/facet
joins with vertebra above
inferior articular process/facet
joins with vertebra below
atlas (C1)
-no body or spinous process
-has posterior/anterior tubercles
-has deep superior articular facets that articulate with occipital condyles
axis (C2)
-has a dens that projects superiorly from the body
function of dens
-allows head to rotate
-acts as a pivot for the rotation of the atlas and skull
C3-C7
-bifid spinous process (except C7)
-transverse foramina
-articular facts lie in oblique plane
-superior articular facets face superoposteriorly
-inferior articular facets face inferioanteriorly
T1-T12
-articulate with ribs
-costal facets on vertebral body and transverse processes
-spinous processes are long and point inferiorly
-articular facets lie in a frontal plane
-superior articular facets face posteriorly
-inferior articular facets face anteriorly
L1-L5
-larger than other two levels
-spinous processes are large, blunt, and point directly posteriorly
-articular facets lie in a sagittal plane
-superior articular facets face medially
-inferior articular facets face laterally
sacrum
triangular bone forming posterior wall of pelvic cavity
number of fused vertebrae of the sacrum
5
coccyx
tailbone
number of fused vertebrae of the coccyx
3-5
thoracic cage
bony frame around chest composed of thoracic vertebrae posteriorly, ribs laterally, and sternum anteriorly
functions of the thoracic cage
-protect heart, lungs, trachea, esophagus, other thoracic organs
-muscle attachments such as pectoral girdles
sternum
breastbone in anterior midline
three parts of the sternum
-manubrium (suprasternal/jugular notch, clavicular notches)
-body
-xiphoid process
ribs
-12 pairs
-articulate posteriorly with thoracic vertebrae
true ribs
ribs 1-7
false ribs
ribs 8-12
floating ribs
ribs 11-12
