REVIEWER FOR PRELIMS Flashcards
(THE SKULL)
head rests on the superior end of the vertebral column and is divided into two main sets of bones:
skull or bony skeleton of the head
which enclose and protect the fragile brain tissue
cranium
which support the eyes and position them anteriorly. They also provide attachment sites for facial muscles which make it possible for us to present our feelings to the world.
facial bone
function of the Cerebral Cranium
to protect the brain from injury.
Part of the skull that encloses the brain. It is also referred to as the “Calvarium/Calvaria” or Brain case or Cranial vault.
CEREBRAL CRANIUM
eight bones that construct the Cranium.
(1) Frontal Bone
(2) Parietal Bones
(1) Occipital Bone
(2) Temporal Bones
(1) Sphenoid Bone
(1) Ethmoid Bone
(FOP EST)
This includes the 14 bones of the face that forms the bony cavities for the protection of the eyes, nasal passages, and mouth.
VISCERAL CRANIUM (FACIAL SKELETON)
THE 14 FACIAL BONES/VISCERAL CRANIUM
- (2) Maxillary Bones
- (2) Zygomatic Bones
- (2) Nasal Bones
- (2) Lacrimal Bones
- (2) Palatine Bones
- (2) Inferior Conchae or Turbinates
- (1) Vomer
- (1) Mandible(MV MZPLIN)
are special interlocking joints between the various bones of the Cerebral Cranium.
Sutures
PARTS OF THE FRONTAL BONE
A. SOPRA ORBITAL BORDERS/SUPRA ORBITAL MARGINS
B. GLABELLA
C. FRONTAL SINUSES (2)
D. NASION
E. SUPRA ORBITAL NOTCH/SUPRA ORBITAL FORAMEN
4 Most Important Sutures of the Skull:
- One CORONAL SUTURE
- One SAGITTAL SUTURE
- One LAMBDOIDAL SUTURE
- Two SQUAMOSAL SUTURES
- This single bone forms the forehead and part of the roof of the skull.
- Its smooth part forms the forehead.
- Its orbital parts form the roof of the orbits.
- And nasal parts help to form the nasal cavities.
FRONTAL BONE
Are the ridges forming the upper margins of the circular openings of the orbits.
SUPRA ORBITAL BORDERS/SUPRA ORBITAL MARGINS
Is a smooth, rounded bony prominence above the nose.
It lies between the supra-orbital borders of the frontal bone.
GLABELLA
Are paired cavities in the squamous or forehead part of the frontal bone, one on each side. They communicate with the nose and vary in size and/or maybe absent.
FRONTAL SINUSES (2)
Is the middle point of the Fronto-Nasal suture.
NASION
is a bony prominence on the outer surface of each parietal bone which is the greatest transverse diameter of the skull.
Parietal Eminence
Lies towards the medial end of each supra-orbital border allowing blood vessels and nerves to pass.
SUPRA-ORBITAL NOTCH/SUPRA ORBITAL FORAMEN.
Are paired bones, one on each side of the Cerebral Cranium.
Forms the lateral wall and part of the roof of the skull.
Meet in the midline of the roof to form the “Sagittal Suture”.
Their anterior borders meet the frontal bone to form the “Coronal Suture”.
PARIETAL BONES (2)
PARTS OF THE OCCIPITAL BONE
A. SQUAMOS PART
B. FORAMEN MAGNUM
C. LATERAL PARTS OF THE OCCIPITAL BONE
D. OCCIPITAL CONDYLES
E. BASE OF THE OCCIPITAL BONE
F. EXTERNAL OCCIPITAL PROTUBERANCE/INION
Is a single bone which forms the posterior part as well as the part of the base or floor of the cerebral cranium.
The Upper posterior border, along with the posterior border of the two parietal bones form the “Lambdoidal Suture”.
OCCIPITAL BONE
is the flat posterior part of the occipital bone.
Squamous Part
is an opening in the lower part of the occipital bone through which the Medulla of the brain leaves the skull, which is formed entirely by the occipital bone
Foramen Magnum
lie on each side of the Foramen Magnum.
Lateral Parts of the Occipital Bone
– are two oval prominences on the under surface of the lateral parts of the foramen magnum
- form the joints with the superior articular surfaces of the first cervical vertebra or Atlas.
Occipital Condyles
part in front of the Foramen Magnum which unite with the Sphenoid bone in front and forms part of the floor of the skull.
Base of the Occipital Bone
is the bony prominence on the outer surface of the squamous part of the occipital bone which is readily palpable.
External Occipital Protuberance/Inion
Forms part of the lateral walls and base of the skull.
Each temporal bone consist of a flat or squamous part above the ear, mastoid portion behind the ear and a petrous part that forms part of the base of the skull
TEMPORAL BONES (2)
PARTS OF THE TEMPORAL BONES
A. ZYGOMATIC PROCESS
B. MASTOID PROCESS
C. MASTOID AIR CELLS
D. PETROUS PART
E. STYLOID PROCESS
F. EXTERNAL AUDITORY MEATUS
G. INTERNAL AUDITORY MEATUS
H. INTERNAL EAR
I. MANDIBULAR OR ARTUCULAR FOSSA
is a slender bony process that extends forward from the squamous part to meet a similar process of the Zygomatic bone forming the “Zygomatic Arch”
Zygomatic Process
is a large rounded bony prominence extending down behind the ear.
Mastoid Process
are small cavities in the mastoid process and adjacent part that communicate with the middle ear.
Mastoid Air Cells
is shaped like a pyramid that extends from the ear medially and forward in the base of the skull. Its inner end is pointed and contains the organ of hearing
Petrous Part
is a sharp pointed process that extends down from the base of the petrous part which is seen in lateral view of the skull outlined behind the mandible. It is an attachment point for muscles and ligaments of the neck
Styloid Process
a tube-like passage extending into the petrous part of the temporal bone.
External Auditory Meatus
lies in the middle or inner part of the petrous, medial to the middle ear. It allows the passage of cranial nerves VII and VIII.
Internal Auditory Meatus
lies in the petrous part and is the organ of hearing.
Internal Ear
a depression on the temporal bone in front of the EAM.
With the capitulum of the mandible, it forms the Temporo-mandibular joint
Mandibular or Articular Fossa
Infection in the middle ear may spread into these cells
Mastoiditis.
A single bone that helps to form a small part of the lateral wall of the skull on each side as well as part of the base of the skull. It is compared to a Bat with two pairs of wings extended
SPHENOID BONE
PARTS OF THE SPHENOID BONE
A. BODY
B. WINGS
C. PTERYGOID PROCESS/PLATES
D. SPHENOID SINUSES
E. OPTIC FORAMEN
F. SELLA TURCICA
G. DORSUM SELLA (BACK OF THE SADDLE)
I. ANTERIOR CLINOID PROCESS
– is the central part that lies in the midline of the floor of the skull, in front of the occipital bone
BODY
extended laterally from the body. There are two pairs; the Greater wings and Lesser wings.
WINGS