A & P II / Skull Bones
Foramen lacerum
Bounded anteriorly by the sphenoid bone, and medially by the sphenoid and occipital bones. Transmits the internal carotid artery and another artery.
Maxillary sinus
"Antrum of Highmore" Each maxillary bone contains one of thesewhich empties into the nasal cavity and contains air.
Crista Galli
"Cock's Comb" A sharp flat pointed process that extends up from the cribiform plate in the midline. It serves as a point of attachment for the membranes that cover the brain.
Lateral masses
"Labyrinths" Compose most of the wall between the nasal cavity and the orbits.
Sella Turcica
"Turk's Saddle" - A depression on the surface of the sphenoid body which houses the pituitary gland.
Fontanel
"fountains" that are "soft spots" Membrane filled spaces that are found in between the cranial bones in newborns and infants where the bone making process is not complete - Allows the cranium to be compressed during birth
Carotid foramen
(Canal) Round and located anterior to the occipital condyles.
Nasion
Bridge of the nose.
8 bones that make up the calvaria
- Frontal Bone (1) - Parietal Bone (2) - Occipital Bone (1) - Temporal Bones (2) - Spenoid Bone (1) - Ethmoid Bone (1)
14 Bones that make up the Visceral Bones
- Maxilla (2) - Maxillae - Zygomatic (Malar Bones) (2) - Nasal Bones (2) - Lacrimal Bones (tear ducts) - (2) - Palatine Bones (2) (L shaped little bones) - Inferior concha (Turbinate) (2) - Vomer (1) -Mandible (1)
On average, how long does it take facial wounds to heal?
1 year
Parietal Bones
2 Bones, one on each side of the cerebral cranium, forms most of the lateral wall and part of the roof of the skull. They meet in the midline of the roof to form the sagittal suture.
Temporal bones
2 bones that form the inferior sides of the cranium and part of the cranial floor. The term tempora pertains to the temples. Each temporal bone has a: - Flat squamous part - Mastoid portion behind ear - Petrous part which forms part of the base of the skull
Nasal fossa or cavities
2 chambers of the nose; they end behind the nasal part of the throat (nasopharynx)
Anterior clinoid processes
2 small bony projections that extend back over the sella turcica from the lesser wing of the sphenoid.
Superior and middle nasal concha (turbinate)
2 thin, scroll shaped bones on eirher side of the nasal septum. They allow the efficient circulation and filtration of inhaled air before it passes into the trachea, bronchi, lungs, and aid in speech.
Teeth
32 bones
Parietal eminence
A bony prominence on each outer surface of the parietal bones. The distance between the 2 eminences is the greatest transverse diameter of the skull, important in childbirth.
Glabella
A flattened area between the frontal eminences and the superciliary arches just superior to the nose.
Supraorbital foramen
A hole within the supraorbital margin just medial to its midpoint in which the supraorbital nerve and artery pass through.
Palatine process
A horizontal projection of the maxilla that forms the anterior and larger part of the hard palate, or anterior portion of the roof of the oral cavity.
Sphenoidal sinus
A large air space which drains into the nasal cavity.
The foramen magnum
A large hole in the inferior part of the occipital bone though which the medulla oblangata and its membranes, the accessory nerve (XI) and the vertebral and spinal arteries pass.
Ethmoid bone
A light spongy bone located in the anterior part of the floor of the cranium between the orbits. Anterior to the sphenoid and posterior to the nasal bones. Forms part of the anterior portion of the cranial floor, the medial wall of the orbits, the superior parts of the nasal septum and most of the sidewalls of the nasal roof.
Infraorbital border
A ridge of bone forming the medial and inferior border of the orbit.
Mastoid process
A rounded projection of the temporal bone posterior to the external auditory meatus. Serves as a point of attachment for several neck muscles.
Frontal squama
A scale like plate, which corresponds to the forehead, gradually slopes down from the coronal suture, then turns abruptly downward.
Suture
A seam or stitch - an immovable joint found only between skull bones
The Frontal Bone
A single bone (which in the fetus is 2 seperate bones) forms the forehead and part of the roof of the skull, the superior portion of the orbits (eye sockets), and most of the anterior part of the cranial floor. The frontal bone is divided by a suture at childbirth and by age 6 the two frontal bones unite to make one frontal bone.
Anterior nasal spine
A single small pointed projection in the midline at the base of the nasal septum. It is located at the acanthion.
Mandibular fossa
A socket of the temporal bone between the squamous and petrous portions which articulates with the mandible.
Supraorbital Margin
A thickening of the frontal bone inferior to the superciliary arches.
Temporal squama
A thin, large, expanded area that forms the anterior and superior part of the temple.
Temporal petrous portion
A triangular portion of the temporal bone located at the floor of the cranial cavity at the base of the skull between the sphenoid and occipital bones. Contains an internal ear, the essential part of the organ of hearing.
Superior orbital fissure
A triangular slit located lateral to the body between the greater and lesser wings. It transmits several nerves.
Mastoid air cells
Air spaces that are seperated from the brain only by thin bony partitions. If mastoiditis, the inflammation of these bony cells, occurs, the infection may spread to the brain and itrs outer covering. The mastoid air cells do not drain as do the paranasal sinuses.
Infraorbital foramen
An opening in the maxilla inferior to the orbit. The infraorbital nerve and artery are transmitted through this opening.
6 Primary fontanels
Anterior - Frontal Posterior - Occipital Anterolateral - (paired) Sphenoidal Posterolateral - (paired) Mastoid
Lesser wings of the Sphenoid
Anterior and superior to the greater wings. They form part of the floor of the cranium and the posterior part of the orbit (eye socket).
Foramen ovale
At the base of the lateral pterygoid process in the greater wing, through which the mandibular branch of the trageminal nerve pass.
Pinna
Auricle - Prominent cartilage of the outer ear.
Clinoid =
Bedpost
Optic foramen
Between the body and the lesser wing in which the optic nerve and opthalmic artery pass through.
Cerebral Cranium
Calvaria 8 Bones
Internal occipital protuberance
Can be seen radiographically.
Orbits
Cavities for the eyeballs
4 Prominent skull sutures
Coronal Suture - Between the frontal & 2 parietal bones Sagittal Suture - Found between 2 parietal bones in the mid-sagittal plain Lambdoidal Suture - Found between the parietal bones and the occipital bone Squamosal Suture - Found between the parietal bone and the temporal bones
Skull
Cranium 22 bones of the skeleton forming the head
Aveolar process
Extends down from the body to accomodate the upper teeth on each side and contain the bony sockets into which teeth are set.
maxilla frontal process
Extends up along the lateral border of the nose and inner part of each infra-orbital margin.
Inion
External occipital protuberance; The bony prominence on the outer surface of the squamous part of the occipital bone in the MSP, which is easily palpated.
Visceral Cranium
Facial Bones
Occipital Bone
Forms the posterior part and the lower 1/3rd of the cranial floor. It joins posteriorly with the two parietal bones to form the lambdoidal suture.
Anterior fontanel
Frontal fontanel ; Bregma; between the angles of the 2 parietal bones and the 2 segments of the frontal bone - diamond shaped - closes in 18-24 months
Auditory Ossicles
In the ears - Malleus - Incus - Stapes
Superciliary arches
Inferior to each frontal eminence. Caused by the projection of the frontal sinuses posterior to the eyebrow.
Frontal eminences
Just above the superciliary arches and below the coronal suture.
Incisive fossa
Just posterior to the incisor teeth in the roof of the mouth.
Body of the maxilla
Large and forms part of the cheek and lies lateral to the nose.
Jugular Foramen
Lateral laterally to the round carotid foramen. The internal jugular vein and several nerves pass through it.
Posterior fontanel
Occipital fontael ; Lambda; between the 2 parietal bones and the occipital bone. Smaller than the anterior fontanel - diamond shaped - closes 2 months after birth
Posterior clinoid processes
On the superior border of the dorsum sella are 2 of these.
Mouth or oral cavity
Opens behind into the lower part of the throat (oropharynx)
Eustachian tube
Or auditory tube - Canal passage from the nasopharynx (throat) to the middle ear. It opens into the throat above the tonsil on each side. If infected, it may cause an earache.
Occipital condyles
Oval processes with the convex surfaces, one on either side of the foramen magnum, which articulates with the depressions on the first cervical vertebra.
Temporal styloid process
Projects downward from the undersurface of the temporal bone and serves as a point of attachment for muscles and ligaments of the tongue and neck.
Zygomatic process
Projects from the inferior portion of the squama. It articulates with the temporal process of the zygomatic bone. Extends laterally from the body to meet the maxillary process of the zygomatic bone.
Ethmoid =
Sieve
Anterolateral fontanel
Sphenoid fontanels; - paired - located on each side of the skull at the junction of the frontal. parietal, temporal, and sphenoid bones - small and irregular shaped - close 3 months after birth
What is the principle supporting structure of the nasal cavity?
The ethmoid bone
The Squamosal part
The flat part at the back of the head.
Base of the occipital bone
The front part of the foramen magnum which unites with sphenoid bone and forms the floor of the skull.
Olfactory foramina
located in the cribiform plate, the olfactory nerves exit from the cavity to the nasal cavities through these.
Dura Mater
The outer meninx (covering) of the brain.
Squama =
scale
Maxillae
The paired maxillary bones unite to form the upper jawbone. The maxillae articulate with every bone of the face except the mandible, as well as with the frontal bone,the sphenoid bone, and ethmoid bone. They form the floor of the orbits, the medial parts of the intra-orbital borders, the lateral walls of the nasal fossae, the floor of the nasal cavities, part of the roof of the mouth (the anterior part), and most of the cheek.
Lateral or external canthus
The point at the outer border of the eye where the upper and lower eyelids meet, A landmark in Radiography
Hyoid Bone
usually broken during strangulation
Cribiform plate =
Horizontal plate. It lies in the anterior floor of the cranium and forms the roof of the nasal cavity.
Greater wings of the Sphenoid
Lateral projections from the body and form the anterolateral floor of the cranium. They also form part of the lateral wall of the skull just anterior to the temporal bone.
Lateral Parts of the occipital bone
Lie on each side of the foramen magnum.
Foramen spinosum
Lies at the posterior angle of the sphenoid and transmits the middle meningeal vessels.
Inner Ear
Lies medially to the middle ear and contains 3 semicircular canals concerned with equillibrium.
Hypoglossal canal
Located at the base of the occipital condyles, it is the fossa (canal) through which the hypoglossal nerve passes.
Foramen rotundum
Located at the junction of the anterior and medial parts of the sphenoid bone. The maxillary branch of the trigeminal nerve passes through it.
Pterygoid processes
Located on the inferior part of the spheroid bone, these structures project interiorly from the points where the body and greater wings unite. They form part of the lateral wall of the nasal cavity.
Temporal mastoid
Located posterior and inferior to the external auditory meatus, or ear canal.
Zygomatic arch
Made up of the zygomatic process of the temporal bone and the temporal process of the zygomatic bone.
Posterolateral fontanel
Mastoid fontanels - paired - located on each side of the skull at the junction of the parietal, occipital, and temporal bones - irregularly shaped - close1-2 months after birth but generally not complete until the age of 1 year
Petrous middle ear cavity
Medial to the ear drum (tympanic membrane) which contain the auditory aussicles, the malleolus, incus, and the stapes, which transmit sound vibrations from the tympanic membrane to the internal ear.
Frontal sinuses
Mucus lined cavities which lie deep to the superciliary arches and act as a sound chamber which gives the voice resonance.
Internal acoustic meatus
Superior to the jugular foramen.
External occipital protuberance
The bony prominence on the outer surface of the squamous part of the occipital in MSP = Inion
External auditory meatus
The canal in the temporal bone that leads to the middle ear.
Sphenoid body
The central part and lies in the midline of the floor of the skull, in front of the occipital bone, and behind the ethmoid bone.
Dorsum Sella
The curved posterior wall of the sella turcica.
Sphenoidal spine
The triangular projection posterior portion of each greater wing that fits into the angle between the squama and petrous portion of the temporal bone.
Nasal Septum
The vertical partition between the 2 nasal fossae
Sphenoid Bone
This single bone helps form a small part of the lateral wall of the skull on each side as well as part of the base (the 2nd level of the floor of the skull). It lies behind the facial bones, with the frontal bone as well, in front. The base of the occipital lies behind it. It has been compared to a bat w/ 2 pairs of extended wings.
Cleft Palate
When the palatine processes of the maxillary bones do not unite before birth, this condition occurs.
