Human Systems And Embryology Flashcards
What are the features of an infant skull?
Eyes are large, ears are low set
Forehead upright and bulbous: face appears broad
Nasal region is vertically shallow with nasal floor close to inferior orbital rim
What are the 3 ways an infant skull can grow?
At sutures or periosteal lined contact areas
In cartilage
By surface deposition
Where in the skull does growth appear at sutures/periosteal lined contact areas?
Between the flat bones of the cranial vault and between the bones of the cranium and maxillary
Where in the skull does growth occur at cartilage?
Synchondroses between the bones forming the base of the skull
In the mandibular condyle and in the cartilage of the nasal septum
Where in the skull does growth occur by surface deposition?
Over the surfaces of the cranial and facial bones
Beneath the covering periosteum
How does the cranial vault grow?
The cranium expands in response to the growing brain (until 6-7 years)
After neural growth ceases, the forehead continues to expand due to enlarging air sinuses
How does the cranial base grow?
Synchondroses
At what age is the lateral growth of the cranial base completed by?
3 years
At what age does the sphenoethmoidal Synchondroses fuse?
6-7 years
At what age does growth cease at the sphenoid-occipital Synchondroses and what age does it fuse?
12-15 years
20 years
What direction does the maxilla grow?
Downward and forward
Where does maxillary growth occur?
At sutures between maxilla and skull
Where does surface deposition occur in maxillary growth?
Posteriorly
Where does surface resorption occur in maxillary growth?
Anteriorly and inferiorly
What direction does the mandible grow in?
Downwards and forwards
