This chapter discusses symptoms, signs, and syndromes related to the head and neck; trauma is not covered. At least nine specialties focus on the head and neck, each developing detailed exams often utilizing specialized instruments. The exams described here are made with resources available to the general clinician. Symptoms, signs, and syndromes primarily of neurologic significance are discussed in Chapter 14. By necessity, these distinctions are somewhat arbitrary. During the head and neck examination the examiner identifies significant abnormalities and identifies signs of systemic disease. As always, knowing the limits of one’s expertize and the indications for specialty referral are imperative.
MAJOR SYSTEMS OF THE HEAD AND NECK
The skull, facial bones, and scalp provide protection and insulation for deeper organs. The scalp and face have a rich vasculature that vasodilates on cold exposure to maintain normal temperature within vital organs. The head contains the organs of special sense: the eyes, ears, olfactory nerve, and taste buds. Special senses are impaired by problems in the sensory organs, cranial nerves, or brain. The tongue, pharynx, and larynx are organs of speech so structural or functional problems alter articulation. The nose, mouth, pharynx, larynx, and trachea form the upper airways. Compromised upper airways affect breathing and voice tone and/or volume. The mouth, teeth, mandible, maxilla, tongue, salivary glands, pharynx, and upper esophagus are the upper alimentary tract necessary for mastication and swallowing. Together the upper airways and digestive tract are the upper aerodigestive tract. The head and neck are highly vascular. The external carotid has rich anastomoses supplying superficial structures so ischemia is unusual. The internal carotid and vertebral arteries supply blood to the brain. The head and neck lymphatic network drains to regional lymph node beds. The tonsils and adenoids are lymphatic organs surrounding the upper aerodigestive tract. The neck contains the thyroid and parathyroid glands, major structures of the endocrine system.
FUNCTIONAL ANATOMY OF THE HEAD AND NECK
The scalp has five layers: the skin, subcutaneous connective tissue, epicranius, a subfascial cleft with loose connective tissue, and the pericranium (Fig. 7-1). The outer three are a single thick, tough, and vascular layer, whose strength is supplied by the epicranius. The epicranius is formed by the frontalis muscle attaching to the occiput by a large central aponeurosis, the galea aponeurotica. The skin and subcutaneous tissue are tightly bound to the galea by fibrous bands that sharply limit the spread of blood or pus. The pericranium, the periosteum of the skull, dips into the sutures limiting spread of subperiosteal blood or pus to the surface of a single bone. The subfascial cleft between the pericranium and galea allows the scalp to be lifted off the skull with minimal effort, allowing blood or pus to spreads widely beneath it. ...