axial bones ppt Flashcards
total bones of axial
80
Axial skeleton are composed of the following bones
• Skull
• Auditory Ossicles
• Hyoid Bone
• Vertebrae
• Thoracic Cage
The bone markings are classified into three (3)
namely:
✓ ARTICULATING
✓ NON - ARTICULATING
✓ DEPRESSIONS AND OPENINGS
enlarged end
head
smooth rounded articular surface
condyle
smooth flattened surface
facet
knob/enlargement
Tuberosity
prominent projection
process
prominent ridge
crest
small rounded projection
tubercle
elongated ridge
line
opening/hole
foramen
depression
fossa
tunnel-like opening
meatus
cleft
fissure
cavity
sinus
The skull has ____ bones
22
The skull has 22 bones
and is divided into two
parts:
a) Calvarium/Cranium
b) Cranial base/ Facial
bones
Forms forehead, superior part of orbits, and most of the anterior cranial fossa;
contains sinuses
frontal bone
✓ Squamous
✓ Supraorbital Margins
✓ Supraorbital Foramen
✓ Glabella
frontal bone
forehead, the most anterior part of the frontal
area
squamous
thickened part which lie under the eyebrows. This is where the forehead ends.
Supraorbital margin
passageway of supraorbital artery and nerves
supraorbital foramen
Form most of the superior and lateral aspects of the skull
parietal bones
interlocking
joints of the skull.
sutures
✓ Coronal Suture
✓ Lambdoid Suture
✓ Squamous Suture
✓ Sagittal Suture
parietal bones
joint between the parietal and frontal bone.
coronal suture
joint between the parietal and occipital bone.
lamboid suture
joint between the parietal and
temporal bone
squamous suture
joint between two parietal bones.
sagittal suture
Form inferolateral aspects of the skull and contribute
to the middle cranial fossa
temporal bones
Best viewed on lateral position
TEMPORAL BONES
temporal bones has 3 major parts
- Squamous
- Tympanic
- Petrous
✓ Zygomatic Process
✓ Zygomatic Arch
✓ Mandibular fossa + Condylar Process
(mandible) = Temporomandibular Joint
TEMPORAL BONE- SQUAMOUS
when the zygomatic process of the temporal bone meets the zygomatic bone, it forms an arch.
Zygomatic Arch
condylar process of the
mandible articulates with the mandibular fossa
Temporomandibular Joint (TMJ)
✓ EAM - External
Acoustic Meatus
TEMPORAL BONE- TYMPANIC
through which the sound enters
the ear, thus enables sound waves to reach the eardrum.
External Auditory Meatus
through which the sound enters
the ear, thus enables sound waves to reach the eardrum.
External Auditory Meatus
supports the temporal brain
Middle cranial fossa
passageway of the jugular vein
jugular foramen
Transmits the internal carotid artery into the cranial
cavity
Carotid canal
between petrous temporal and sphenoid. Most
medial portion
foramen lacerum
transmits cranial nerves
internal acoustic meatus
which acts as an anchoring site for some neck muscles. Can be felt as a lump just posterior to the ear. This
has many air cavities called “mastoid air cells”
mastoid process
needle like process which is not just for neck attachment but also for tongue muscles.
styloid process
allows passage of the maxillary division of cranial nerve V.
Foramen Rotundum
allows passage of the mandibular division of cranial
nerve V
Foramen Ovale
allows passage of the middle meningeal
artery.
Foramen Spinosum
✓ Jugular Foramen
✓ Foramen Lacerum
✓ Internal Acoustic Meatus
TEMPORAL BONE- PETROUS
✓ Foramen Rotundum
✓ Foramen Ovale
✓ Foramen Spinosum
TEMPORAL BONE- PETROUS
✓ Mastoid Process
✓ Styloid Process
TEMPORAL BONE- PETROUS
supports the cerebellum
Posterior cranial fossa
largest foramen of the skull, spinal cord passes through.
foramen magnum
located on each lateral side of the foramen magnum. This is where C1 articulates.
.Occipital condyles
Most bulging part of the
posterior skull.
External occipital protuberance
Forms posterior aspect and most of the base of the skull
OCCIPITAL BONE
✓ Posterior Cranial Fossa
✓ Foramen Magnum
occipital bone
✓ Occipital Condyles
✓ External Occipital Protuberance
OCCIPITAL BONE
Keystone of the cranium; contributes to the middle cranial fossa and orbits;
SPHENOID BONE
✓ Body
✓ Hypophyseal Fossa of Sella Turcica
SPHENOID BONE
which forms the center of the
sphenoid bone.
body of the sphenoid
houses the
pituitary gland
SKULL: CALVARIUM
Hypophyseal fossa of the sella turcica
✓ Lesser Wing
✓ Greater Wing
✓ Pterygoid Process
SPHENOID BONE
medial process, horn-like
lesser wing
projects laterally
greater wing
interior portion, which serves as an attachment for pterygoid muscles for chewing
Pterygoid process
Helps to form the anterior cranial fossa; forms part of the nasal septum and the lateral
walls and roof of the nasal cavity; contributes to the medial wall of the orbit
ETHMOID BONE
✓ Cribriform Plate
✓ Crista Galli
✓ Perpendicular Plate
ETHMOID BONE
helps form the root of the nasal cavities and floor of the anterior cranial fossa
Cribriform plate
the dura matter, specifically the falx cerebri of the brain is attached to this structure to help secure the
brain in the cranial cavity
Crista galli
inferior portion, which divides the nasal cavity from right to left.
Perpendicular plate
The lower jaw
mandible
✓ Paired Rami
✓ Mandibular Angle
✓ Body of Mandible
✓ Condylar Process
mandible
✓ Coronoid Process
✓ Mandibular Foramen
✓ Mental foramen
mandible
Between each ramus and the body of mandible is a formed angle known as mandibular angle.
paired rami
articulate with the temporal bones in the TMJ of the jaw.
Condylar processes
insertion points for the temporalis
muscle
Coronoid processes
permit the inferior alveolar nerves to pass.
Mandibular foramina
allow blood vessels and nerves to pass to the chin and lower lip.
Mental foramina
Form the upper jaw and parts of the hard palate, orbits, and nasal cavity walls
maxilla
✓ Anterior Nasal Spine
✓ Infraorbital Foramen
maxilla
bony projection located at the
midline of the maxilla (upper jaw) at the lower end of the
nasal cavity.
Anterior Nasal Spine
allows passage of the the
infraorbital nerve to the skin of face.
Infraorbital Foramen
Form the cheeks and part of the orbits
zygoma
articulations of zygoma
- Maxilla
- Frontal Bone
- Temporal Bone
Form the bridge of the nose
nasal bone
Nasal bone ARTICULATIONS
- Maxilla
- Frontal Bone
- Perpendicular plate
Form part of the medial orbit wall
LACRIMAL BONE
houses the lacrimal sac, which helps to
drain the tears into the nasal cavity.
Lacrimal fossa
Form posterior part of the hard palate and a small part of nasal cavity and orbit
walls
PALATINE BONE
medial fusion point of the
horizontal plates of the palatine bones which form the
posterior part of the hard palate
Median palatine suture
Inferior part of the nasal septum
vomer
unique in that it is the only bone of the body that does not articulate
directly with any other bone.
hyoid bone
Three bones in the middle ear that are among the smallest bones in the
human body.
AUDITORY OSSICLES
✓ Malleus
✓ Incus
✓ Stapes
AUDITORY OSSICLES
✓ Backbone
✓ 33 bones(infant)
✓ 26 bones (adult)
✓ 5 regions
• Cervical (7)
• Thoracic (12)
• Lumbar (5)
• Sacral (1-5)
• Coccygeal (1-4)
VERTEBRAL COLUMN
1.Cervical Lordosis (Concave)
2.Thoracic Kyphosis (Convex)
3.Lumbar Lordosis (Concave)
4.Sacral Kyphosis (Convex)
curves
Each vertebra consists of a _____, or ______, anteriorly and a __________ posteriorly. The disc-shaped body is the weight- bearing
region.
body, centrum, vertebral arch
flattened plates that fuse in the median plane, complete
the arch posteriorly.
laminae
short bony pillars projecting posteriorly from the vertebral
body, form the sides of the arch.
Pedicles
median posterior projection arising at the junction
of the two laminae.
Spinous process
extends laterally from each side of the vertebral
arch.
Transverse process
protrude superiorly and
inferiorly respectively from the pedicle.
.Superior and inferior articular facet
✓ Body: None
✓ No spinous
process
✓ Has superior
articular
facets
✓ “YES”
CERVICAL – ATLAS(C1)
✓ Not as
specialized as
atlas
✓ Unique
feature:
knoblike
dens
CERVICAL SPINE – AXIS (C2)
✓ Body: Oval
✓ Spinous process
is short and bifid
✓ Vertebral
foramen is
triangular
✓ C7-palpable
CERVICAL SPINE – C3-C7
✓ Body: Heart
shaped
✓ Long and sharp
spinous process
✓ Demifacets
(Costal Facets)
✓ Transverse
process
✓ Vertebral foramen
is round
THORACIC SPINE: T1-T12
✓ Body: Massive
kidney -shaped
✓ Short and flat
spinous process
✓ Pedicles and laminae
are thicker and
shorter
✓ Transverse process
✓ Vertebral foramen is
triangular
LUMBAR SPINE: L1-L5
Atlas + Occipital condyles
Atlanto-occipital joint
Atlas + Axis
Atlanto-axial joint
Superior articulating facet + Inferior
articulating facet
Zygapophyseal joint
Protects the vital organs in the thorax
THORACIC CAGE
Elements of the thoracic cage include the
thoracic vertebrae posteriorly, the ribs
laterally, and the sternum and costal
cartilages anteriorly.
THORACIC CAGE
includes the manubrium, body of sternum, and the xiphoid process. It lies in the anterior midline of the thorax.
Sternum (breastbone)
consists of 24 pairs
ribs
first to seventh pair
true ribs
seventh to twelfth pair. The eleventh and twelfth pairs
are specifically considered as floating ribs.
false ribs
• Ribs + Vertebrae
Costovertebral joints
Ribs + Costal cartilages
Costochondral joints
Sternum + Costal cartilages
Sternochondral joints
False ribs costal cartilages
Interchondral joints
