skull and foramina

Question 1

find a diagram and locate all skill and facial anatomy

Question 2

what are the 6 cranial bones

Answer 2

• frontal
• parietal
• occipital
• temporal
• sphenois
• ethmoid

Question 3

what are the 5 facial bones

Answer 3

• lacrimal
• nasal
• maxillary
• zygomatic
• mandible

Question 4

what 2 cranial bones does the coronal suture seperate

Answer 4

frontal and parietal

Question 5

what bone does the saggital suture seperate

Answer 5

the left and right parietal bone

Question 6

what skull bones do the lambdoid suture seperate

Answer 6

parietal and occipital bone

Question 7

what bones does the occipital mastoid suture seperate

Answer 7

occipital and mastoid part of temporal bone

Question 8

what bones does the squamous suture seperate

Answer 8

• temporal and parietal

(squamous part of temporal bone from parietal)

Question 9

what do you call the junction where the coronal and sagittal suture meet

Answer 9

bregma (top of head)

Question 10

what do you call the junction where the lambdoid and sagittal suture meets

Answer 10

lambda

Question 11

what do you call the junction where the frontal, parietal, temporal and sphenoid bone meet

Answer 11

pterion

Question 12

what part of the skull is the weakest part

Answer 12

pterion junction

Question 13

what structure lays beneath the pterion junction

Answer 13

• anterior division of the middle meningeal artery

Question 14

a blow to the pterion junction can cause a middle meningeal artery rupture

Question 15

what is a fontanelle

Answer 15

spaces between the bones of the skull where bone formation isn’t complete in foetus

Question 16

what are the 4 fontanelles of foetuses

Answer 16

• anterior
• posterior
• sphenoid
• mastoid

Question 17

what what ages do the different fontanelles fuse

Answer 17

anterior = 1-2 yrs old

posterior = 2-3 months

sphenoid = 6 months

mastoid = 6-18 months

Question 18

what suture do infants have that adults dont

Answer 18

metopic

Question 19

what does it mean if you see a depressed anterior fontanelle in a baby

Answer 19

• dehydrated, malnutrition

Question 20

what does it mean if u see a bulging anterior fontanelle

Answer 20

• raised intracranial pressure e.g meningitis

Question 21

the fontanelles can be used as ‘windows’ to undertake ultrasound assessment of underlying brain

cranial ultrasound cant be done one fontanelle have fused as US waves cannot penetrate through bone

Question 22

by what age should the metopic suture in babies be closed by

Answer 22

9 months

Question 23

keep in mind that metopic suture may persist (only in 3%) and be mistaken for a frontal lobe fracture or frontal sinus agenesis/ hypoplasia

Question 24

what is hypoplasia

Answer 24

the incomplete development or underdevelopment of an organ or tissue

Question 25

what is frontal sinus agenesis

Answer 25

The absence of a frontal sinus makes the skull more heavy and increases the sense of frontal headache

Question 26

what can premature closure of the metopic suture (craniosynostosis) result in and what is this

Answer 26

trigonocephaly - triangular apperance of the frontal skull

Question 27

besides the pterion junction, where is another weak part in the skull

Answer 27

- cribriform plate (located in the anterior cranial fossa)

Question 28

what are the 2 foramina found in the anterior crania fossa

Answer 28

- cribriform plate - optical canal

Question 29

what are the 4 foramen found in the middle cranial fossa

Answer 29

- foramen rotundum - fortamen ovale - foramen spinosum - foramen lacerum

Question 30

what are the 4 foramen found in the posterior cranial fossa

Answer 30

- internal acoustic meatus - foramen magnum - jugular foramen - hypoglossal canal

Question 31

what are the 4 bones that form the roof and floor of the nasal canal

Answer 31

nasal ethmoid maxilla palatine

Question 32

what 2 tissue structures are found in the nasal canal

Answer 32

nasal septum nasal turbinates

Question 33

what are the 4 bones and singular cartilage that make up the nasal septum

Answer 33

- perpendicular plate of ethmoid - septal cartilage - vomer - maxilla - palatine bone

Question 34

what are the 4 sinuses found in the face

Answer 34

frontal ethmoid sphenois maxilla

Question 35

give some reasons for the function of the paranasal sinuses

Answer 35

- humifidying/heating air - resonance to noise - providing maximal strength for minimal material - reduction of skull weight - increasing facial dimension for origin of cranial muscle - evolutionary remnants

Question 36

which sinus would not be visible for an AP xray of the face

Answer 36

sphenoidal sinus

Question 37

note that sinuses are very small at birth so you will not be able to see them in xray of newborn

Question 38

when you look at paranasal sinuses, what is the first thing you investigate

Answer 38

symmetry of the sinueses

Question 39

what is sinusitis

Answer 39

inflamed sinuses

Question 40

what does sinusitis look like on CT and why

Answer 40

grey area as a result of excess mucus or swelling of tissue linings - swelling can cause obstruction of passage to nasal cavity thus favouring infection to grow

Question 41

what is the uncinate processes

Answer 41

thing bone/ hook on the medial wall of the maxillary sinuses just below the connection with the nasal cavity

Question 42

how can the variation in the length of the uncinate process cause pathology

Answer 42

if the uncinate process is very long, the passage from the maxillary sinuses to middle meatus is narrow and might get more easily obstructed , mucus can cause inflammation