Skeletal Systems II: Axial Skeleton Flashcards
what are the two regions of the skull?
neurocranium and viscerocranium
neurocranium function
responsible for housing and protecting the brain
neurocranium composition
consists of the calvarium(brain case) and basicranium (brain pan)
viscerocranium function
- bones of the face
- allows for the passage of substances into the body (food, air, water) and mastication of food
what is mastication?
chewing
components of the neurocranium
- frontal bone
- parietal bones
- occipital bone
- temporal bone
- sphenoid bone
- ethmoid bone
neurocranium frontal bone function
- protects brain anteriorly
- supports brain inferiorly
- root of orbit
what is the orbit?
eye socket
neurocranium parietal bones function
protects brain/skull laterally and superiorly
neurocranium occipital bone function
protects brain posteriorly
components of neurocranium occipital bone
- foramen magnum
- occipital condyles
neurocranium occipital bone foramen magnum function
- passage of spinal cord
- it’s a large circular opening (largest in body)
neurocranium occipital bone occipital condyles function
- articulates with the first vertebra
- allows the head to flex and extend
what is the first vertebra also called?
the cervical atlas
neurocranium temporal bone structure
inferior, lateral side of skull
neurocranium temporal bone zygomatic arch function
-connects the temporal process of zygomatic bone and zygomatic process of the temporal bone
neurocranium temporal bone mastoid process location
- behind the ear
- -> bulge on inferior part of temporal bone
neurocranium temporal bone mastoid process function
-attachment site of some neck muscles to extend and rotate the head
what is another name for the zygomatic arch?
cheek bone
neurocranium temporal bone styloid process location
-slender pointed piece of bone just below the ear
neurocranium temporal bone styloid process function
-attachment site of the hyoid and tongue muscles
neurocranium temporal bone internal auditory meatus location
- located inside the posterior cranial fossa of the skull
- near the center of the posterior surface of the petrous part of the temporal bone
- (ear canal)
neurocranium temporal bone internal auditory meatus function
-transmits cranial nerves
neurocranium temporal bone petrous location
- pyramid-shaped
- is wedged in at the base of the skull between the sphenoid and occipital bones
- separates middle from cranial posterior fossa
neurocranium temporal bone petrous function
- protects sensory structures of the inner ear
- ex: hearing and equilibrium
components of the neurocranium temporal bone
- petrous
- mastoid process
- zygomatic process
- styloid process
- internal auditory meatus
- zygomatic arch
neurocranium temporal bone zygomatic process location
-long, arched process projecting from the lower part of the squamous portion of the temporal bone
neurocranium temporal bone zygomatic process function
-curves laterally and anteriorly to unite with the temporal process of the zygomatic bone
neurocranium sphenoid bone location
-floor of cranium
neurocranium sphenoid bone function
- unites many cranial and facial bones
- articulates with almost every other bone in the skull
neurocranium sphenoid bone sella turcica function
-site of pituitary gland
what gland is the pituitary gland a part of?
endocrine gland
neurocranium sphenoid bone sella turcica location
-saddle-shaped region in sphenoid midline
neurocranium ethmoid bone location
-forms the roof of the nasal cavity, upper nasal septum, and part of the medial orbit walls
neurocranium ethmoid bone function
-main mechanical support structure of the nasal cavity
components of the neurocranium ethmoid bone
- cribriform plates
- crista galli
- perpendicular plate
neurocranium ethmoid bone cribriform plates location
-bony plates lateral to the crista galli
neurocranium ethmoid bone cribriform plates function
-allows passage of olfactory nerve
neurocranium ethmoid bone crista galli location
- upper part of the perpendicular plate
- above cribriform plate
neurocranium ethmoid bone crista galli function
- attachment of dura mater
- helps secure the brain within the skull
neurocranium ethmoid bone perpendicular plate location
- thin, flattened lamina
- descends from the under surface of the cribriform plate
neurocranium ethmoid bone perpendicular plate function
-assists in forming the septum of the nose
components of viscerocranium
zygomatic bone, maxilla, mandible, nasal bones, vomer, hard palate
viscerocranium zygomatic bone location
- cheek and lateral orbit(cheekbone)
- lateral to the maxilla
viscerocranium maxilla location
- upper jaw/teeth
- anterior portion of hard palate
viscerocranium mandible location
-lower jaw/teeth
viscerocranium nasal bones location
bridge of nose
viscerocranium vomer location
-forms inferior septum with perpendicular plate of ethmoid
viscerocranium hard palate location
- nasal opening
- made up of two palatine bones
- posterior roof of mouth
rib cage sternum location
breastplate
components of rib cage sternum
-manubrium, body, xiphoid process
rib cage sternum manubrium location
- handle
- upper triangular-shaped portion
rib cage sternum body location
- largest elongated portion
- lies between manubrium and xiphoid process
rib cage sternum xiphoid process location
-sword; most inferior and smallest portion
rib cage “sternal angle” location
- located at the junction of the manubrium and the body of the sternum
- it’s a bony landmark used to locate the junction of the 2nd rib and the sternum
rib cage jugular notch location
-the slightly curved region on the superior angle of the manubrium
rib cage ribs location
- 12 ribs that forms the walls of the thorax and protect the thoracic organs
- ribs that attach to the spinal cord attach via the hyaline costal cartilage
rib cage true ribs numbers
1-7
rib cage true ribs function
-articulate directly with the sternum with their own costal cartilage
rib cage false ribs numbers
8-10
rib cage false ribs function
-articulate indirectly by attaching to the cartilage of rib 7
rib cage floating ribs numbers
11-12
rib cage floating ribs function
-do not articulate anteriorly
components of a rib
- body
- head
- articular facets
- sternal end
rib cage rib body location
-main portion
rib cage rib head location
- the posterior end
- articulates with thoracic vertebrae
rib cage rib articular facets location
-the points of contact with the vertebral column
rib cage rib sternal end location
-attachment site of costal cartilage
rib cage intercostal spaces location
- located between the ribs
- contains muscles, nerves, and blood vessels
vertebral column of axial skeleton
-consists of 33 individual bones called vertebrae
what are the regions of the vertebral column each called?
- cervical
- thoracic
- lumbar
- sacral
- coccygeal
how many bones are within the cervical region of the vertebral column?
7
how many bones are within the thoracic region of the vertebral column?
12
how many bones are within the lumbar region of the vertebral column?
5
how many bones are within the sacral region of the vertebral column?
5
how many bones are within the coccygeal region of the vertebral column?
3-5
major components of vertebrae in the vertebral column
- body
- nueral arch
- articular components
vertebral column vertebra body location
- anterior, rounded area
- each bears the load of the bodies above it
vertebral column vertebra neural arch location
- posterior arch
- encloses the spinal cord
vertebral column vertebra articular components location
-contains surfaces where adjacent vertebrae(2) attach
common landmarks in the vertebral column
- vertebral foramen
- spinous process
- transverse process
- articular process
- lamina
- pedicle
- intervertebral foramen
vertebral column landmark vertebral foramen
- passageway formed by the vertebral arch and the body
- enclosed by the spinal cord
vertebral column landmark spinous process
- non-paired posterior projection of vertebral arch
- “the bumps on your back”
vertebral column landmark transverse process
-extends laterally from each pedicle
vertebral column landmark articular process
- two bilateral superior and inferior facets
- >these articulate with the vertebra above and below
vertebral column landmark lamina
-bridges transverse and spinous processes
vertebral column landmark pedicle
-bridges transverse processes and body
vertebral column landmark intervertebral foramen
- lateral openings found between the vertebrae(pedicles and spinal nerves)
- spinal nerves are found here
what separates the individual vertebrae from one another?
-intervertebral discs
intervertebral discs composition
- anulus fibrosis
- nucleus pulposus
anulus fibrosis composition
-outer ring of tough, dense fibrocartilage
nucleus pulposus composition
- softer, gelatinous inner region
- used for cushioning
vertebral foramen unique characteristics regions
- cervical region
- thoracic region
- lumbar region
vertebral foramen unique characteristics: cervical region
- two cervical vertebrae
- uniquely shaped
- possess elements that allow for movement of the head and neck
vertebral foramen unique characteristics: cervical region: C1
- Axis
- posterior tubercle
- condylar facets
- fovea for the dens
vertebral foramen unique characteristics: cervical region: C1 posterior tubercle
-no spinous process or body
vertebral foramen unique characteristics: cervical region: C1 condylar facets
- articulates with the occipital condyles of the skull
- allows for head extension/flexion
vertebral foramen unique characteristics: cervical region: C1 fovea for the dens
-rounded grooves for dens of axis
vertebral foramen unique characteristics: cervical region: C2
- superior articular facets
- dens (odontoid process)
vertebral foramen unique characteristics: cervical region: C2 superior articular facets
- inferior to C1
- contains body and spinous process
vertebral foramen unique characteristics: cervical region: C2 dens
- rests against forea of atlas
- bound together by transverse ligament
- head rotation
vertebral foramen unique characteristics: cervical region: C3-C7
- bifid(forked) spinous process
- transverse foramina
- smaller compared to lower regions
what does bifid mean?
-it’s split in two
vertebral foramen unique characteristics: cervical region: C3-C7 transverse foramina
-allows passage of vertebral artery
what are shared features among the vertebral foramen cerival region C1-C7?
- lamina
- superior/inferior articular facets
- pedicle
- transverse processes
vertebral foramen unique characteristics: thoracic region components
- has spinous process (narrow, angled inferiorly)
- has superior and anterior articular facets
- ribs articulate with them^ at costal facets at two points
- > demifacets & broad transverse processess
- doesn’t have transverse foramen**
vertebral foramen unique characteristics: lumbar region components
- no costal facets**
- broad, big, square spinous process
- bears most of the weight
types of natural abnormal spine curvatures
- scoliosis
- kyphosis
- lordosis
scoliosis
lateral curvature
kyphosis
- aka “hunch back”
- thoracic region
- vertebral column curves posteriorly
lordosis
- aka “sway back” or “booty back”
- lumbar region
- vertebral column curves excessively anteriorly
sacrum
- pelvic spine
- last major spine
coccyx
- aka “tailbone”
- consists of 4 small vertebrae
- vestigial
fontanels
- areas of hard bone
- ->going through birth canal
- brain growth
hyoid bone
-located in the C3 vertebrae
