The skull is a closed cavity with numerous apertures for neurovascular
transmission. Like the other body cavities, there is constant equalization
of pressure between the CSF and venous systems via the arachnoid
villi and the apertures. When this becomes lop-sided, it is the
soft neural structures and their vascular supplies that are compromised.
The neck is a transmission zone between multiple regions. It
contains a high concentration of vital structures in a small area
(similar to the internal capsule of the brain), so small pathology
can cause big pathology.
The head and neck are now called modules*. The regions* that make up the head can be grouped into cranial*, facial* and airway*. The regions that make up the neck* can be grouped into superficial and deep. The head and neck contain vital fragile structures, and great awareness is required in dealing with patients having potentially life-threatening injuries - in fact, the most important diagnostic aid is clinical awareness.
Certain conditions require urgent referral to specialists but
this does not excuse ignorance of acute management* before
referral.
Goiter is enlargement of the thyroid gland due to any cause and
may be toxic* or non-toxic*. Gross appearance may be diffuse*, nodular* or multinodular*.