Skull Flashcards
(107 cards)
State the functions of the skull
Supports and protects the brain; isotropic resistance to impact by dispersing forces
Describe the layers of the skull
External (outer) table and internal (inner) table with diploe in the middle (bubbly less solid structure)
How can the skull be split in to two sections?
Neurocranium: aspects supporting and containing the brain; Viscerocranium: facial aspects that aid in talking, breathing etc
What is excess cranial bone called?
Wormian bones which do not have names but are small amounts of bone that sit between the sutures
What lies between cranial bones?
Sutures: joints between cranial lines which will not move (with exception to mandible)
Name the outer and inner surfaces of the skull
Ectocranial (outside) and endocranial (inside).
How can the neurocranium be split?
Membranous/dermatocranium: mainly the flat bones of the skull cap e.g. frontal & parietal - formed through intramembranous ossification ; Cartilaginous/chondrocranium: More complex structures e.g. sphenoid and ethmoid which border on mixing with viscerocranium - formed by endochondral ossification (start as cartilage)
Name the bones of skull
Cranial: frontal, parietal (x2), occipital, temporal (x2), ethmoid, sphenoid ; Facial: maxillae (x2), palatines (x2), nasals (x2) lacrimals (x2), zygomatics (x2), vomer, inferior nasal conchae (x2), manidble ; Ear ossicles: malleus, incus, stapes.
Name the type of suture that is present in childhood but can stay as a non-metric trait in adults
Metopic suture
Name the sutures of the skull
(Synchondroses): coronal, sagittal, squamous (overlapping), lambdoid, lambda, bregma, pterion, frontomaxillary, frontonasa, frontozygomatic, intermaxillary, median palatine, occipitomastoid, parietomastoid, sphenofrontal, sphenooccipital, sphenoparietal, sphenosquasomal, sphenozygomatic, temporozygomatic, transverse palatine, zygomaticomaxillary, tempomandibular joint, atlanto-occipital joint
Name the 12 cranial nerves and their type of nerve function
CNI - Olfactory (S) ; CNII - Optic (S) ; CNIII - Oculomotor (M) ; CNIV - Trochlear (M) ; CNV - Trigeminal (S&M) ; CNVI - Abducens (M) ; CNVII - Facial (S&M) ; CNVIII - Vestibulocochlear/Auditory (S) ; CNIX - Glossopharyngeal (S&M); CNX - Vagus (S&M) ; CNXI - Accessory (M) ; CNXII - Hypoglossal (M)
Which nerve has 3 branches and what are they?
CNV - Trigeminal (S&M): 1 - Ophthalmic, 2 - Maxillary, 3 - Mandibular.
Which bones are part of the neurocranium?
Frontal, parietal, temporal, occipital, sphenoid, ethmoid
What bones does frontal articulate with?
Parietals, zygomatics, lacrimals, nasals, maxillae, sphenoid, ethmoid
Name and detail the eminences at the front of the frontal bone
Frontal bosses: more significant in females ; marks ossification centres of frontal bone
Name the features just above the orbits
Glabella / supraorbital ridge : of the frontal bone (brown ridge)
Describe the temporal line
Attachment site of temporalis formed by mastication; (temporalis will run through the zygomatic foramen to the coronoid process of the mandible) ; runs across the frontal and parietal bones on either side
Describe the supraorbital margin and a feature within it
Feature of the frontal bone directly above the orbitals superior to the eyes ; supraorbital notch or foramen (if closed) is found here
Describe the nasal spine
The inferior aspect of the frontal bone that comes down to join the nasals
What part of the frontal bone articulates to the zygomatic bones on either side?
Zygomatic processes
Describe the frontal sinuses
Located at the medial inferior aspect of the front bone; air cells that are pockets within the bone; can be used for ID in forensics
Name and detail the structure that runs down the internal midline of the frontal bone
Frontal crest: Anchors the flax celebri (fold of the dura mater (outermost layer of brain surrounding)) ; runs between the sinuses as a slightly raised line ; is continuous with the sagittal sulcus
Describe sagittal sulcus
(Sagittal sinus) for venous drainage, is continuous with the frontal crest of the frontal bone and continues on to the parietal bones
Describe arachnoid granulations / fovae
Run on the internal surface of the frontal and parietal bones along the top on either side of the sagittal sulcus - they are small holes left by the membrane pushing out leading to resorption of the bone