bones and fossae

Question 1

how many bones in the adult cranium

Answer 1

• 22 bones in the adult cranium
• plus the 6 bones of the middle ear and the mandible

Question 2

regions of the brain

Answer 2

the skull can be divided into 2 regions - the neurocranium that protects the brain and the viscerocranium that forms the face

Question 3

functions of the skull

Answer 3

• protects the brain and the organs of special sense
• provides openings for passage of food and air
• houses teeth for mastication

Question 4

neurocranium

Answer 4

8 cranial bones
- frontal, parietal, sphenoid, ethmoid, temporal, occipital

Question 5

viscerocranium

Answer 5

14 facial bones

Question 6

temporal fossa

Answer 6

a shallow depression on the temporal region of the skull. it forms one of the largest landmarks of the skull.

Question 7

how does the temporal fossa communicate with infratemporal fossa

Answer 7

inferiorly via and opening deep to the zygomatic arch

Question 8

what is the temporal fossa mainly occupied by

Answer 8

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

Question 9

infratemporal fossa

Answer 9

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

Question 10

what does the infratemporal fossa contain

Answer 10

it contains superficial muscles, including the lower part of the temporal muscle, the lateral pterygoid muscle, and the medial pterygoid muscle

Question 11

what blood vessels and nerves does the infratemporal fossa contain

Answer 11

• the middle meningeal artery
• the pterygoid plexus
• the mandibular nerve and its branches

Question 12

pterygopalatine fossa

Answer 12

pyramidal-shaped space inferior to the apex of the orbit
- lies anterior to the pterygoid process of the sphenoid and posterior to the maxilla

Question 13

what does the pterygopalatine fossa contain

Answer 13

neurovascular structures:
- pterygopalatine ganglion
- maxillary artery and its branches
- emissary veins
- maxillary division of trigeminal nerve
- nerve of the pterygoid canal

Question 14

foramina and fissures

Answer 14

foramen - opening or hole
fissure - slit-like groove

transmit nerves and blood vessels

Question 15

anterior cranial fossa foramen and fissures

Answer 15

• cribriform plate

Question 16

middle cranial fossa - foramen and fissures

Answer 16

• superior orbital fissure
• optic canal
• foramen rotundum
• foramen ovale
• foramen spinosum

Question 17

posterior cranial fossa - foramen and fissures

Answer 17

• internal acoustic (auditory) meatus
• jugular foramen
• hypoglossal canal
• foramen magnum

Question 18

cribriform plate

Answer 18

location - ACF
opens into nasal cavity
- transmits olfactory nerve

Question 19

superior orbital fissure

Answer 19

location. - MCF
opens into orbit
-transmits- oculomotor nerve, trochlear nerve, abducens nerve, ophthalmic vein, ophthalmic division of trigeminal nerve

Question 20

optic canal

Answer 20

location MCF
opens into - orbit
transmits optic nerve and ophthalmic artery

Question 21

foramen rotundum

Answer 21

location - MCF
opens into - pterygopalatine canal -> infraorbital fissure -> orbit
transmits maxillary division of trigeminal nerve

Question 22

foramen ovale

Answer 22

location - MCF
opens into infratemporal fossa
transmits mandibular division of trigeminal nerve

Question 23

foramen spinosum

Answer 23

location MCF
open into infratemporal fossa
transmits middle meningeal vessels

Question 24

foramen lacerum

Answer 24

location MCF
opens into - this is a gap between the petrous part of temporal bone and the sphenoid bone
transmits - cartilage, internal carotid artery

Question 25

internal acoustic meatus

Answer 25

location - PCF opens into - petrous temporal bone transmits - facial nerve, vestibulocochlear nerve, labyrinthine artery

Question 26

jugular foramen

Answer 26

location - PCF opens into neck transmits - glossopharyngeal nerve, vagus nerve, spinal accessory nerve, internal jugular vein

Question 27

hypoglossal canal

Answer 27

location - PCF - externally this sits just under the occipital condyle opens into neck transmits hypoglossal nerve

Question 28

foramen magnum

Answer 28

location - PCF opens into neck transmits - medulla oblongata and meninges, spinal part of accessory nerve, vertebral arteries, anterior and posterior spinal arteries

Question 29

inferior orbital fissure

Answer 29

location - between posterior wall of maxilla and greater wing of sphenoid opens into orbit transmits maxillary nerve and infraorbital vessels

Question 30

stylomastoid foramen

Answer 30

location - external surface between styloid and mastoid processes exits - petrous temporal bone transmits facial nerve

Question 31

carotid canal

Answer 31

location - external surface in the petrous portion of the temporal bone merges with foramen lacer transmits internal carotid artery

Question 32

mandibular foramen

Answer 32

location - medial aspect of mandibular ramus opens into - mandibular canal transmits inferior alveolar nerve and vessels

Question 33

mental foramen

Answer 33

location - lateral aspect of the body of the mandible opens onto chin transmits mental nerve and vessels

Question 34

incisive foramen

Answer 34

location - hard palate, posterior to central incisors, in midline opens onto roof of mouth transmits - nasopalatine nerve

Question 35

grater palatine foramen

Answer 35

location - posterior hard palate, medial to 3rd molar opens onto roof of mouth transmits greater palatine nerve and vessels

Question 36

lesser palatine foramen

Answer 36

location - posterior hard palate, posterior to greater palatine foramen opens onto roof of mouth transmits lesser palatine nerve and vessels

Question 37

infraorbital foramen

Answer 37

location - maxilla opens onto cheek transmits infraorbital nerve and vessels