bones and fossae Flashcards
how many bones in the adult cranium
- 22 bones in the adult cranium
- plus the 6 bones of the middle ear and the mandible
regions of the brain
the skull can be divided into 2 regions - the neurocranium that protects the brain and the viscerocranium that forms the face
functions of the skull
- protects the brain and the organs of special sense
- provides openings for passage of food and air
- houses teeth for mastication
neurocranium
8 cranial bones
- frontal, parietal, sphenoid, ethmoid, temporal, occipital
viscerocranium
14 facial bones
temporal fossa
a shallow depression on the temporal region of the skull. it forms one of the largest landmarks of the skull.
how does the temporal fossa communicate with infratemporal fossa
inferiorly via and opening deep to the zygomatic arch
what is the temporal fossa mainly occupied by
mainly occupied by the temporalis muscle which has a wide attachment spread across the fossa.
the temporal fossa also harbours some important neurovascular structures such as the deep temporal vessels and nerves
infratemporal fossa
large space which is medial to ramus of mandible, lateral to lateral pterygoid plate, posterior to maxillary tuberosity and anterior to tympanic part of the temporal bone
what does the infratemporal fossa contain
it contains superficial muscles, including the lower part of the temporal muscle, the lateral pterygoid muscle, and the medial pterygoid muscle
what blood vessels and nerves does the infratemporal fossa contain
- the middle meningeal artery
- the pterygoid plexus
- the mandibular nerve and its branches
pterygopalatine fossa
pyramidal-shaped space inferior to the apex of the orbit
- lies anterior to the pterygoid process of the sphenoid and posterior to the maxilla
what does the pterygopalatine fossa contain
neurovascular structures:
- pterygopalatine ganglion
- maxillary artery and its branches
- emissary veins
- maxillary division of trigeminal nerve
- nerve of the pterygoid canal
foramina and fissures
foramen - opening or hole
fissure - slit-like groove
transmit nerves and blood vessels
anterior cranial fossa foramen and fissures
- cribriform plate
middle cranial fossa - foramen and fissures
- superior orbital fissure
- optic canal
- foramen rotundum
- foramen ovale
- foramen spinosum
posterior cranial fossa - foramen and fissures
- internal acoustic (auditory) meatus
- jugular foramen
- hypoglossal canal
- foramen magnum
cribriform plate
location - ACF
opens into nasal cavity
- transmits olfactory nerve
superior orbital fissure
location. - MCF
opens into orbit
-transmits- oculomotor nerve, trochlear nerve, abducens nerve, ophthalmic vein, ophthalmic division of trigeminal nerve
optic canal
location MCF
opens into - orbit
transmits optic nerve and ophthalmic artery
foramen rotundum
location - MCF
opens into - pterygopalatine canal -> infraorbital fissure -> orbit
transmits maxillary division of trigeminal nerve
foramen ovale
location - MCF
opens into infratemporal fossa
transmits mandibular division of trigeminal nerve
foramen spinosum
location MCF
open into infratemporal fossa
transmits middle meningeal vessels
foramen lacerum
location MCF
opens into - this is a gap between the petrous part of temporal bone and the sphenoid bone
transmits - cartilage, internal carotid artery
internal acoustic meatus
location - PCF
opens into - petrous temporal bone
transmits - facial nerve, vestibulocochlear nerve, labyrinthine artery
jugular foramen
location - PCF
opens into neck
transmits - glossopharyngeal nerve, vagus nerve, spinal accessory nerve, internal jugular vein
hypoglossal canal
location - PCF - externally this sits just under the occipital condyle
opens into neck
transmits hypoglossal nerve
foramen magnum
location - PCF
opens into neck
transmits - medulla oblongata and meninges, spinal part of accessory nerve, vertebral arteries, anterior and posterior spinal arteries
inferior orbital fissure
location - between posterior wall of maxilla and greater wing of sphenoid
opens into orbit
transmits maxillary nerve and infraorbital vessels
stylomastoid foramen
location - external surface between styloid and mastoid processes
exits - petrous temporal bone
transmits facial nerve
carotid canal
location - external surface in the petrous portion of the temporal bone
merges with foramen lacer
transmits internal carotid artery
mandibular foramen
location - medial aspect of mandibular ramus
opens into - mandibular canal
transmits inferior alveolar nerve and vessels
mental foramen
location - lateral aspect of the body of the mandible
opens onto chin
transmits mental nerve and vessels
incisive foramen
location - hard palate, posterior to central incisors, in midline
opens onto roof of mouth
transmits - nasopalatine nerve
grater palatine foramen
location - posterior hard palate, medial to 3rd molar
opens onto roof of mouth
transmits greater palatine nerve and vessels
lesser palatine foramen
location - posterior hard palate, posterior to greater palatine foramen
opens onto roof of mouth
transmits lesser palatine nerve and vessels
infraorbital foramen
location - maxilla
opens onto cheek
transmits infraorbital nerve and vessels
