CH7 Axial skeleton
Shape of palatine bones
L-shaped
What bones form the orbit
Three cranial and four facial
What is the sphenoid bone called
keystone of the cranial floor
What is the smallest face bone
lacrimal
what do the lacrimal fossa and maxilla form
lacrimal sac that will gather tears and it will pass through the fossa into the nasal cavity
where is the cribriform plate located
lies in the anterior floor of the cranium and forms the roof of the nasal cavity
define mastoid process
located posterior and inferior to the external auditory meatus
what is ethmoid bone considered
major superior supporting structure of nasal cavity
maxillae does not articulate with
mandible
all Facial bones are paired except for
mandible and vomer
bone features of mandible
mental foramen, alveolar part, mandibular foramen, mandibular condyle
mnemonic for facial bones
my mandible chews nine very large zucchini pizzas
Structures of axil skeleton
skull, hyoid bone, auditory ossicles, vertebral column, thorax (sternum, ribs)
what are fontanels
soft spots in the skull
cavities have a similar function to
spongy bone in long bones
head of rib articulates with
superior and inferior costal facets of thoracic cavity
where is the crista galli
superior part of ethmoid bone but inferior part of cranial cavity
what does the perpendicular plate form
superior part of nasal septum
Define sella turcica
superior surface of body of sphenoid
what does the vomer articulate with
superiorly with perpendicular plate of ethmoid and sphenoid inferiorly with maxillae and palatine
fontanels turn into
sutures
what does the hyoid bone support
tongue
tubercle of rib articulates with
transverse costal facets of thoracic vertebrae
vertebrosternal ribs
true ribs 1-7 connected to sternum by individual costal cartilages
define occipital condyle
two oval processes with convex surfaces, one on either side of foramen magnum. They articulate with depressions on the first cervical vertebra (atlas)
Define hypoglossal canal
under occipital condyle, runs to tongue
what is inside the cartilage of intervertebral disc
water mucus soft substance called nucleus pulposus. w/ age it converts to fibrocartilage as it gradually becomes less hydrated. decreases in size w/age too
purpose of curve in vertebral column
will increase strength and help maintain balance in upright position. also absorbs shocks during walking and protects in from fracture
vertebral ribs
(floating ribs): 11-12 (no anterior cartilage)
abnormal curvatures add
"hyper" before word
parts of typical vertebra
- Body (Centrum) - Vertebral Arch - Processes - intervertebral disc
Frontal bone forms facial icons
-Forehead -Eye socket (superior part) -Also forms much of the anterior part of the cranial floor
Number of cranial bones
8
purpose of fontanels
1. Allow skull to change shape as it passes through the birth canal 2. Permits rapid growth of brain during infancy
Bone features of the occipital bone
1. Foramen magnum 2. occipital condyles 3. hypoglossal canal 4. jugular foramen
5 openings of orbit
1. Optic foramen 2. Superior orbital fissure 3. Inferior orbital fissure 4. Supraorbital foramen 5. Lacrimal fossa
bone features of ethmoid bone
1. perpendicular plate 2. cribriform plate 3. crista galli 4. superior and middle nasal conchae
bone features of the sphenoid bone
1. sella turcica 2. optic canal 3. superior orbital fissure 4. foramen rotundum 5. foramen ovale 6. foramen spinosum
bone features of temporal bone
1.zygomatic process 2. mandibular fossa 3. mastoid process 4. carotid canal 5. styloid process 6. external and internal acoustic meatus
how many bones in thoracic vertebrae
12
How many bones in the appendicular system
126
Number of facial bones
14
vertebrae is _____ of body's total height
2/5
adult vertebral column
26 vertebrae
how many bones in coccyx
3-5 fused
early development vertebrae
33 vertebraes
how many bones in lumbar
5
how many bones in sacrum
5 fused
how many bones in cervical vertebrae
7
How many bones in the axial skeleton
80
define lordosis
Abnormal anterior curvature of spine usually lumbar and cervical
Functions of cranial bones in terms of auditory ossicles
Amplifies sound waves to hear.
Where are lacrimal bones located
Anterior portion of the medial wall of the eyesocket
Why are cavities important
Because the skull will grow in size during development without making them heavier
squamous suture
Between parietal and temporal bones
What does the sphenoid bone resemble
Butterfly
What do nasal bones provide attachment for
Facial expression muscles
where does the intervertebral disc start
C2
Features of parietal bones
External surfaces are convex. Pretty flat bone
Function of cranial bones in providing protection and support to other systems
Digestive and respiratory system, special senses organs
The inferior nasal concha is not part of what bone
Ethmoid
Purpose of inferior nasal concha
Helps to swirl and filter air before he passes into lungs. Also warm air
Role of cranial bones in stabilization
Inner surfaces attach to the meninges
Two periods of facial enlargement
Irruption of teeth and onset of puberty
Why is the sphenoid bone called the keystone
It articulates with all other cranial bones, providing considerable stability to the skull
The mandible is the
Largest and strongest facial bone
What does the maxillae form
Lateral walls and floor of nasal cavity, floor of Orbits, most of the interior hard palate
How is the hyoid bone held in place?
Ligaments and muscles from temporal bone
function of paranasal sinuses
Lighten the skull Give resonance and amplification to voice
zygomatic bone articulates with
Maxillary, temporal, frontal, and sphenoid bones
Inner ear purpose
Monitor position and movement of head which provides balance
What does the parietal bone form
Much of the sides and roof of the cranial cavity
Role of cranial bones and muscle attachment
Outer surfaces- move the head and facial expressions
describe maxillae
Paired bone the unites to form upper jaw
Describe the shape of inferior nasal concha
Paired scroll like shaped
What is usually absent during birth
Paranasal sinuses
What does zygomatic bone form
Parts of lateral and floor of orbit
What does the Palatine bones form
Posterior edge of the hard palate, portion of the nasal cavity wall and floor, portions of the eyesocket
what does the occipital bone form
Posterior wall and the posterior floor of the cranial cavity
order of foramen features in sphenoid
ROS rotundum, ovale, spinosum
The vertebral column serves as points of attachment for
Ribs, muscles of the back, pelvic girdle, and muscles of upper limbs
describe shape of nasal bones
Small, flattened, regular shaped
Unique features of the skull
Sutures, Paranasal sinuses, Fontanels
What do the temporal bones form
The inferior lateral part of the cranial floor plus parts of the lateral wall near the ear
how are fontanels replaced
They are replaced by bone through intramembranous ossification
shape of hyoid bone
U-shaped
Describe vomer bone
Unpaired triangular shaped bone
define kyphosis
abnormal posterior curvature of thoracic spine (humpback)
which bone features are found in sacrum
ala, articular process, hiatus, foramen, canal
where is the ethmoid bone located
anterior to sphenoid and posterior to nasal bones
Movable bones in the skull
auditory ossicles, occipital bone, mandible
why does our voice sound different when we have a cold
bc chambers are filled w/more mucus
coronal suture
between frontal and parietal bones
lamboidal suture (Skull)
between occipital and parietal bones
sagittal suture
between parietal bones
adult normal curvatures
cervical (baby starts holding head up straight) lumbar (starts to sit up and walk)
vertebral column parts
cervical, thoracic, lumbar, sacrum (fused sacral vertebrae), coccyx (fused coccygeal vertebrae)
What are the zygomatic bones
cheek bones
vertebrochondral ribs
false ribs 8-10 from vertebrae to cartilage
what are intervertebral disc formed of
fiber cartilage (annulus fibrosus)
cranial bones that form orbit
frontal, sphenoid, ethmoid
what cavities are paranasal sinuses in
frontal, sphenoid, ethnoid
where are fontanels found and what do they consist of
in developing embryos and cartilage and messenchyme
What does the vomer form
inferior part of nasal septum
define mandibular fossa
inferoposterior surface of the zygomatic process of the temporal bone is this socket
bone features of maxillae bone
infraorbital foramen and alveolar part
fetal curvature
one curvature, concave anteriorly, primary curvature
what is the hyoid bone
only bone that does not articulate with another bone
what are nasal bones
paired bones that form bridge of nose
define carotid canal
passageway for internal carotid artery
define jugular foramen
posterior to carotid foramen and anterior to the occipital bone, a passageway for the jugular vein
define styloid process
projects inferiorly from the inferior surface of the temporal bone and serves as point of attachment for muscles and ligaments of the tongue and neck
neck of the rib articulates with
runs parallel to transverse process
what fuses in an adult vertebrae
sacrum and coccyx
the lacrimal bone forms part of
the eye socket or orbit
Define Foramen Magnum
the hole in the base of the skull through which the spinal cord passes.
What is the nasal septum formed by
the perpendicular plate of ethmoid, vomer, and inferiorly by vomer bone
define zygomatic process
the temporal bone articulates with the zygomatic bone
describe paranasal sinuses in terms of resonating chamger
they will be able to intensify and prolong the sounds, thereby giving an enhancement of quality of voice