Axial Skeleton Flashcards
The Axial Skeleton is composed of _____ bones
80
A. Skull –
B. Hyoid –
C. Auditory Ossicles –
D. Thorax (Sternum and Ribs) -
E. Vertebra –
22
1
6
25
26
Bone markings
- articulating
- non-articulating
- depression/opening
Articulating
- Head – enlarged end
- Condyle – smooth rounded articular surface
- Facet – smooth flattened surface
Non – Articulating
- Tuberosity – Knob/Enlargement
- Process- prominent projection
- Crest – prominent ridge
- Tubercle
- Line
Depressions/Opening
- Foramen – opening/hole
- Fossa – depression
- Meatus – tunnel-like opening
- Fissure – cleft
- Sinus – cavity
________ has 22 bones and divided into two:
SKULL
1. Calvarium/cranium (Braincase) – Superior aspect
2. Cranial base (Facial bones) – inferior
Calvarium (STEP OF 6)
- Sphenoid (Unpaired)
- Temporal
- Ethmoid (Unpaired)
- Parietal
- Occipital
- Frontal
Forms the forehead, superior part of orbits and most of the
anterior cranial fossa; contains sinuses
FRONTAL BONE
FRONTAL BONE
a.
b.
c.
d.
squamous
supraorbital margin
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
Forms most of the superior and lateral aspects of the skull.
PARIETAL BONE
interlocking joints of the skull / wormian bones
Sutures
a. Coronal Suture -
b. Lambdoidal Suture -
c. Squamousal Suture -
d. Sagittal Suture -
- parietal - frontal
- parietal – occipital
- parietal – temporal
- parietal bones
- Form the inferolateral aspects of the skull and contribute to
the middle cranial fossa. - It is best viewed on a lateral position.
TEMPORAL BONES
3 major parts of temporal bones:
- Squamous
- Tympanic
- Petrous
Squamous
1.
2.
Zygomatic Arch
Temporomandibular Joint (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 (TMJ)
- through which the sound enters the ear, thus enables sound waves to reach the eardrum.
External Auditory Meatus (found in Tympanic)
- thickest and hoses the middle and internal ear cavities
Petrous
Petrous:
1.
2.
3.
4.
5.
6.
7.
- Middle cranial fossa
- Jugular Foramen
- Carotid canal
- Foramen Lacerum
- Internal Acoustic Meatus
- Mastoid process
- Styloid process
supports the temporal brain
Middle cranial fossa
most lateral foramen, passageway of the jugular vein
Jugular Foramen
- anterior to the 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
- acts as an anchoring site for some neck muscles.
- Can be felt as a lump just posterior to the ear.
- 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
Forms most of the skull’s posterior wall and base.
OCCIPITAL BONE