Lecture 1 - Skull Flashcards
Pagets disease
-what is it?
Thickening of the skull (rare)
-not enough space for brain, go in and remove the skull and replace with 3D printer
What type of joints are sutures?
Where are lamboid, coronal squamous, spehnopartietal and occipitomastoid , sagitall sutures
fibrous joints - only in the skull
What is a fontanelle , why is this important?
Part of brain in baby that has not formed a suture yet
- Important as can see weather cranial pressure has increased in babies, or baby dehydrated ect. examine this
- Anterior fontanelle - 18 (12-20ish) months it ossifies
- is at front of head (sagittal suture)
- Posterior - ossifies around 6 months
- dont really care about lateral fontanel
- Lamboid suture - should ossify by 6 months - we see alot of cases where it ossifies earlier
Bregma
Where the sagital and coronal sutures meet
-If there is a delayed or early ossification then there will be some clinical cases
Pterion - clinical significance
surface anatomy
Pterion - is the weakest past (not the thinest)
- All sutures form an edge here
- articulation of bones - frontal, sphenoid, parietal, temporal
- Artery running right through here - anterior branch of Middle menangial arteries
- if break these arteries can get an extradural hemorrhage
Surface anatomy
2.5 cm above the zygomatic arch (formned by zygomatic process of temporal bone and temporal process of zygomatic bone) and 2.5cm posterior to the lateral orbital margin and is a 1cm circle
- can see this on xrays (need to be bale to know which bone is damaged) - see if intact of not
- is made up of frontal, sphenoid, partial and temporal bones
Mastoid process significance
Sternocleidomastoid muscle attaches here
Facial nerve runs through here (deep to the structure) - if taking out parotid gland need to be careful
What does an extradural hemorrhage look like on CT scan
- e.g due to someone punching someones head to pterion point
- can see on a CT scan
- can see inflammation of soft tissue outside of skull
- can see the lighter colour - which is the hemorrhage inside the skull
Sinuses - what age do they develop
- and what are the 5 sinuses
- what can we see on a CT scan?
2 or 1 year old baby does not have sinuses
- usually fully developed by age 14
- Sinusitis - is not seen in children as their sinuses have not formed yet
- can see it on a CT scan
- can see if it is dark - then clear sinus, but on other side the sinus is filled - grey
- acute - only a few days
- Chronic - can get mucosa of sinus - may thicken and fill whole area
What muscles attatch to the mastoid process?
Posterior digastric and sternocleidomastoid muscles.
What articulates with the occipital condyles
Atalas (c1) superior facets
Lambda
sagital suture meets lamboid suture
-Posterior fontanelle
what attaches to the mandibular fossa process
mandibular fossa - temporomandibular joint
temporal bone
1st question of test - foramen - which bone they lie and what travels through them
lecter
Need to know different parts of mandible
lecutre
Findings of the Pterion and middle menangial artery paper
- Aims to find the surface markings of the pterion and relationship to middle menangial artery
- Landmarks - frontozygomatic suture, and zygomatic arch
- Frontozygoamtic suture - found on lateral border of orbit and is palpable
- Most pterions were sphenoparietal type - spehnoid articulates directly with partieal bone
- Suggests using frontozygomatic suture instead of zygomatic arch
- pterion 2.6cm behind and 1.3cm above the posterolateral margin of frontozygomatic suture
- 2/3rd of subjects pterion covered the anterior branch of middle menangial artery , or if not - found a few mm posterior
- Limitations - only done on indian skulls, some ethnic variations
