Skull Flashcards
The function of the skull
Protection - the skull is the receptacle for the most highly developed part of the nervous system, the brain
Also supports the Face, which in turn supports and protects sensory organs connected with the CNS. Sight, Hearing, taste, smell
The face also contains the nasal and oral cavities.
The initial parts (& functions) of the digestive (i.e. mastication) and respiratory systems are situated in this part of the skeleton.
In the adult, the skull & face consists of 22 individual bones, 21 of which are immobile and united into a single unit. The 22nd bone is the mandible (lower jaw), which is the only moveable bone of the skull.
Bones of the skull (8)
Frontal Bone
Parietal Bones (x2)
Temporal Bones (x2)
Sphenoid bone
Ethmoid Bone
Occipital Bone
Function of sutures
Allow deformation during birth.
Absorb shocks during early years.
Respond to support rapid brain growth
Fuse between 2 and 3 years
Become extremely strong joints after fusion.
What is a suture
A suture is the immobile joint between adjacent bones of the skull.
All the suture names
Saggital
Coronal
Lambdoid
Squamosal
What are Fontanelles
Fontanelles are the soft spots on an infant’s head where the bony plates that make up the skull have not yet come together. It is normal for infants to have these soft spots, which can be seen and felt on the top and back of the head. Fontanelles that are abnormally large may indicate a medical condition.
What is Craniosynostosis
Fibrous sutures prematurely close, & disrupt normal growth patterns causing abnormal head shape. 1:2000 births
When would we do Imaging of the Skull.
Most Head Trauma now goes to CT and most Trauma Hospitals have two CT scanners.
CT not Working
Paediatric lower dose than CT
Skeletal Survey
What Views would we perform? for skull imaging
Occipito-Frontal
Occipito –Frontal 30 degree Cranial
Fronto – Occipital (supine)
Fronto – Occipital 30 degree Caudal (supine)
Lateral – erect or supine
Towne’s
Occipito – frontal View
The patient is seated facing the erect bucky, so that the median sagittal plane is with the midline of the bucky and perpendicular to it.
The Neck is flexed to bring orbito meatal line perpendicular to the bucky, this can be achieved by ensuring the nose and forehead are in contact with the bucky.
Occipito –Frontal 30 degree Cranial
The patient is seated facing the erect bucky, so that the median sagittal plane is with the midline of the bucky and perpendicular to it.
The Neck is flexed to bring orbito meatal line to 45 degree angle to the bucky, this can be achieved by ensuring the chin is in contact with the bucky and also using a 45 degree pad.
Lateral skull– erect or supine
Patient sits facing the bucky and the head is then rotated such that the median sagittal plane is parallel to bucky and inner orbital line is perpendicular to it.
Position the IR landscape in the erect bucky with the border being 5am above the vertex of the skull.
Towne’s View technique
Patient with the back against the IR bucky ensuring the MSP is perpendicular to the IR, by tucking the chin down the orbito-meatal line will be perpendicular with the image receptor.
Angle the Central ray 35 degrees Caudal.
What is Pagets disease.
Bone cells are constantly dying and being replaced by new ones. With paget’s disease of bone, this process is disrupted. Bone is broken down at a faster rate than normal. In response to the speedy loss of bone cells, the body makes new bone cells very quickly. These are then badly ‘woven’ back into the bone, and as a result, bones are weaker. They are also bigger, because the body has produced more new bone cells than it needs.
What is Multiple Myeloma.
Generalised osteopaenia and/or lytic bone deposits on plain film radiography. Sharply defined, small lytic areas (average size 20 mm) of bone destruction with no reactive bone formation. The pattern of destruction may be geographic, moth eaten or permeated. Pathological fractures are common.
