Axial Skeleton Flashcards
Axial Skeleton composed of the following bones:
Skull
Auditory Ossciles
Hyoid bone
Vertebrae
Thoracic Cage
how many bones in skull?
22
how many bones are in auditory ossicles?
6
how many bones are in hyoid bone?
1
how many bones are im vertebrae?
26
how many bones are in thoracic cage?
25
total axial bones
80
bone markings classified into three:
articulating
non-articulating
depressions and opening
articulating
head
condyle
facet
enlarged end
head
smooth rounded articular surface
condyle
smooth flattened surface
facet
non-articulating
tuberosity
process
crest
tubercle
line
knob/enlargement
tuberosity
prominent projection
process
prominent ridge
crest
small rounded projection
tubercle
elongated ridge
line
depressions and openings
foramen
fossa
meatus
fissure
sinus
opening/hole
Foramen
depression
fossa
tunnel-like opening
meatus
cavity
sinus
cavity
sinus
cleft
fissure
The skull has 22 bones and is divided into two
parts:
a) Calvarium/Cranium
b) Cranial base/ Facial bones
STEP OF 8
Sphenoid
Temporal
Ethmoid
Parietal
Occipital
Frontal
Forms forehead, superior part of orbits, and most of the anterior cranial fossa; contains sinuses
Frontal bone
Parts of frontal bone
Squamous
Supraorbital margins
Supraorbital foramen
Glabella
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
Form most of the superior and lateral aspects of the skull
Parietal bones
interlocking joints of the skull
Sutures
parts of the parietal bones
Coronal suture
Lamboid suture
Squamous suture
Sagittal suture
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 bone
Best viewed on lateral position
Temporal bones
major parts of temporal bones
Squamous
Tympanic
Petrous
Mandibular fossa + Condylar Process (mandible) =
Temporomandibular joint
temporal bone - squamous
zygomatic arch
TMJ
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
Temporal bone - tympanic
External auditory meatus
through which the sound enters
the ear, thus enables sound waves to reach the eardrum.
External auditory meatus
Temporal bone - petrous
Middle cranial fossa
Jugular foramen
Caratoid canal
Foramen lacerum
Internal acoustic meatus
Mastoid process
Styloid process
Foramen rotundum
Foramen ovale
Foramen spinosum
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 auditory meatus
which acts as an anchoring site for some neck
muscles. Can be felt as a lump just posterior to the ear.
Mastoid process
The mastoid has many air cavities called
Mastoid air cells
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 mandibular division of cranial
nerve V.
Foramen ovale
allows passage of the middle meningeal
artery.
Foramen spinosum
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
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
Keystone of the cranium; contributes to the middle cranial fossa and orbits;
Sphenoid bone
which forms the center of the sphenoid bone.
Body of the sphenoid
houses the pituitary gland
Sella turcica
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
helps form the root of the nasal cavities
and floor of the anterior cranial fossa
Criniform 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
parts of skull: calvarium
vomer
inferior nasal conchae 2
nasal 2
maxilla 2
mandible 2
palatine 2
zygoma 2
lacrimal 2
the lower jaw
mandible
parts of the mandible
Paired rami
Condylar process
Coronoid process
Mandibular foramina
Mental foramina
Between each ramus
Paired rami
the body of mandible is a formed angle known as
mandibular angle
articulate with the temporal bones in the TMJ of the jaw
Condylar process
insertion points for the temporalis muscle
Coronoid process
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
Parts of maxilla
Anterior nasal spine
Infraorbital foramen
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
Articulations of nasal bone
Maxilla
Frontal bone
Perpendicular plate
Form part of the medial orbit wall
Lacrimal
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
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
Lateral walls of the nasal septum
Inferior nasal conchae
Lateral walls of the nasal septum
Inferior nasal conchae
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
Vertebral column
Backbone
33 bones (infant)
26 bones (adult)
5 regions
5 regions of vertebral column
Cervical - 7
Thoracic - 12
Lumbar - 5
Sacral 1-5
coccygeal 1-4
Curves
Cervical lordosis (concave)
Thoracic kyphosis (convex)
Lumbar lordosis (concave)
Sacral kyohosis (convex)
consists of a body, or centrum, anteriorly and a
vertebral arch posteriorly.
Vetebra
The disc-shaped body is the weight- bearing
region.
Vertebra
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
a 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
includes the manubrium, body of sternum,
and the xiphoid process. It lies in the anterior midline of the thorax.
Sternum
includes the manubrium, body of sternum,
and the xiphoid process. It lies in the anterior midline of the thorax.
Sternum
consists of 24 pairs.
Ribs
first to seventh pair
True ribs
The eleventh and twelfth pairs
are specifically considered as
Floating ribs
