Clinical ANATOMY of Head & Neck

Clinical ANATOMY of Head & Neck Dr. Mujahid Khan

Sebaceous Cyst • The skin, the subcutaneous tissue, and the epicranial aponeurosis are closely united to one another and are separated from the periosteum by loose areolar tissue • The skin of the scalp possesses numerous sebaceous glands • The ducts are prone to infection and damage by combs • Therefore sebaceous cysts of the scalp are common

Lacerations of the Scalp • The scalp has a profuse blood supply to nourish the hair follicles • Even a small laceration of the scalp can cause severe blood loss • It is difficult to stop the bleeding because the arterial walls are attached to fibrous septa in the subcutaneous tissue • Are unable to contract or retract to allow blood clotting to take place • Local pressure applied to the scalp is the only satisfactory method to stop the bleeding

Life-Threatening Scalp Hemorrhage • All the superficial arteries supplying the scalp ascend from the face and the neck • In an emergency situation, encircle the head just above the ears and eyebrows with a tie, shoelaces, or even a piece of string and tie it tight • Insert a pen, pencil, or stick into the loop and rotate it so that the tourniquet exerts pressure on the arteries

Scalp Infection • Infections of the scalp tend to remain localized • Are usually painful because of the abundant fibrous tissue in the subcutaneous layer • Infection may spreads by the emissary veins, causing osteomyelitis • Infected blood may travel by the emissary veins into the venous sinuses and produce venous sinus thrombosis • Blood or pus may collect in the potential space beneath the epicranial aponeurosis

Trigeminal Neuralgia • The facial skin receives its sensory nerve supply from the trigeminal nerve • Trigeminal neuralgia is a relatively common condition • Patient experiences severe pain in the distribution of the mandibular or maxillary division • The ophthalmic division usually escaping

Face Infections • The area of facial skin bounded by the nose, the eye, and the upper lip is a potentially dangerous zone to have an infection • A boil in this region can cause thrombosis of the facial vein • Causing spread of organisms through the inferior ophthalmic veins to the cavernous sinus • Resulting cavernous sinus thrombosis may be fatal unless adequately treated with antibiotics

Bell’s Palsy • The facial muscles are innervated by the facial nerve • Damage to the facial nerve causes distortion of the face, with drooping of the lower eyelid, and the angle of the mouth will sag on the affected side

Clinical Significance of TMJ • The temporomandibular joint lies immediately in front of the external auditory meatus • Temporomandibular ligament prevents the head of the mandible from passing backward and fracturing the tympanic plate when a severe blow falls on the chin • The articular disc of the temporomandibular joint may become partially detached from the capsule • Its movement become noisy and producing an audible click during movements at the joint

Dislocation of TMJ • Dislocation occurs when the mandible is depressed • In bilateral cases the mouth is fixed in an open position • Both heads of the mandible lie in front of the articular tubercles • Reduction of the dislocation is achieved by pressing the gloved thumbs downward on the lower molar teeth and pushing the jaw backward

Parotid Duct Injury • The parotid duct is a comparatively superficial structure on the face • May be damaged in injuries to the face or by cut during surgical operations on the face

Frey’s Syndrome • It develops after penetrating wounds of the parotid gland • If patient eats, beads of perspiration appear on the skin covering the parotid • Caused by damage to the auriculotemporal and great auricular nerves • During the process of healing, the parasympathetic secretomotor fibers in the auriculotemporal nerve grow out and join the distal end of the great auricular nerve • These fibers reach the sweat glands in the facial skin • A stimulus intended for saliva production produces sweat secretion instead

Submandibular Gland Calculus • The submandibular gland is a common site of calculus formation • It is rare in the other salivary glands • Examination of the floor of the mouth reveals absence of ejection of saliva from the orifice of the duct of the affected gland • Stone can be palpated in the duct, which lies below the mucous membrane of the floor of the mouth

Sublingual Gland Cyst • The sublingual salivary gland lies beneath the sublingual fold of the floor of the mouth • It opens into the mouth by numerous small ducts • Blockage of one of these ducts is believed to be the cause of cysts under the tongue

Lymphoid Tissue of Pharynx • At the junction of the mouth with the oral part of the pharynx, and the nose with the nasal part of the pharynx, are collections of lymphoid tissue of considerable clinical importance • The palatine tonsils and the nasopharyngeal tonsils are the most important

Tonsilitis • The palatine tonsils reach their maximum normal size in early childhood • Gradually atrophy after puberty • Palatine tonsils are a common site of infection • Producing the characteristic sore throat and pyrexia • The deep cervical lymph node is usually enlarged and tender • Recurrent attacks of tonsillitis are best treated by tonsillectomy

Quincy • A peritonsillar abscess is caused by spread of infection from the palatine tonsil to the loose connective tissue outside the capsule • This is called quinsy

Adenoids • Excessive hypertrophy of pharyngeal tonsils are referred to as adenoids • Marked hypertrophy blocks the posterior nasal openings and causes the patient to snore loudly at night and to breathe through the open mouth • It may be the cause of deafness and recurrent otitis media • Adenoidectomy is the treatment of choice for hypertrophied adenoids with infection

Piriform Fossa • The piriform fossa is a recess of mucous membrane situated on either side of the entrance of the larynx • It is bounded medially by the aryepiglottic folds and laterally by the thyroid cartilage • It is a common site for the lodging of sharp ingested bodies such as fish bones. The presence of such a foreign body immediately causes the patient to gag violently

Fontanelles • Palpation of the fontanelles enables to know the progress of growth in surrounding bones • The degree of hydration of the baby • The state of intracranial pressure • Samples of cerebrospinal fluid can be obtained by passing a long needle obliquely through the anterior fontanelle into the subarachnoid space or even into the lateral ventricle • It is usually not possible to palpate the anterior fontanelle after 18 months

Tympanic Membrane • At birth, the tympanic membrane faces more downward and less laterally than in maturity • If examined with the otoscope it lies more obliquely in the infant than in the adult

Forceps Delivery • Mastoid process is not developed in the newborn infant • The facial nerve emerges from the stylomastoid foramen and is close to the surface • It can be damaged by forceps in a difficult delivery

Fractures of Anterior Cranial Fossa • In these fractures the cribriform plate of the ethmoid bone may be damaged • This usually results in tearing of the overlying meninges and underlying mucoperiosteum • Patient bleeds from the nose (epistaxis) and leakage of cerebrospinal fluid into the nose (cerebrospinal rhinorrhea) • Fractures involving the orbital plate of the frontal bone result in hemorrhage beneath the conjunctiva and into the orbital cavity, causing exophthalmos • The frontal air sinus may be involved, with hemorrhage into the nose

Fractures of Middle Cranial Fossa • These fractures are common, because this is the weakest part of the base of the skull • This weakness is caused by the presence of numerous foramina and canals in this region • Cavities of the middle ear and the sphenoidal air sinuses are particularly vulnerable • Leakage of CSF and blood from the external auditory meatus is common • Blood and cerebrospinal fluid may leak into the sphenoidal air sinuses and then into the nose

Fractures of Posterior Cranial Fossa • In these fractures blood may escape into the nape • Later, it tracks between the muscles and appears in the posterior triangle, close to the mastoid process • The mucous membrane of the roof of the nasopharynx may be torn, and blood may escape there

Common Facial Fractures • Nasal Fractures • Maxillofacial Fractures • Blowout Fractures of the Maxilla • Fractures of the Zygoma or Zygomatic Arch

Intracranial hemorrhage • Extradural hemorrhage results from injuries to the meningeal arteries or veins • Subdural hemorrhage results from tearing of the superior cerebral veins at their point of entrance into the superior sagittal sinus • Subarachnoid hemorrhage results from leakage or rupture of a congenital aneurysm on the circle of Willis or, less commonly, from an angioma • Cerebral hemorrhage is generally caused by rupture of the thin-walled lenticulostriate artery, a branch of the middle cerebral artery

Tympanic Membrane • Otoscopic examination of the tympanic membrane is done by first straightening the external auditory meatus by gently pulling the auricle upward and backward in the adult, and straight backward or backward and downward in the infant • Normally, the tympanic membrane is pearly gray and concave

Otitis Media • Pathogenic organisms can reach the middle ear by ascending through the auditory tube from the nasal part of the pharynx • Acute infection of the middle ear called otitis media • It produces bulging and redness of the tympanic membrane

Otitis Media • If not treatment otitis media can result in the spread of the infection into the mastoid antrum and the mastoid air cells called acute mastoiditis • It may be followed by the further spread of the organisms beyond the confines of the middle ear • Meninges and the temporal lobe of the brain lie superiorly • Spread of the infection in this direction could produce a meningitis and a cerebral abscess in the temporal lobe

Otitis Media • Beyond the medial wall of the middle ear lie the facial nerve and the internal ear • A spread of the infection in this direction can cause a facial nerve palsy and labyrinthitis with vertigo • Posterior wall of the mastoid antrum is related to the sigmoid venous sinus • If the infection spreads in this direction, a thrombosis in the sigmoid sinus may well take place

Examination of Mouth • A physician must be able to recognize all the structures visible in the mouth and be familiar with the normal variations in the color of the mucous membrane covering underlying structures • The sensory nerve supply and lymph drainage of the mouth cavity should be known • The close relation of the lingual nerve to the lower third molar tooth should be remembered • The close relation of the submandibular duct to the floor of the mouth may enable one to palpate a calculus in cases of periodic swelling of the submandibular salivary gland

Laceration of Tongue • A wound of the tongue is often caused by the teeth following a blow on the chin while the tongue is partly protruded from the mouth • It can also occur when a patient accidentally bites the tongue while eating, during recovery from an anesthetic, or during an epileptic attack • Bleeding is halted by grasping the tongue between the finger and thumb posterior to the laceration, thus occluding the branches of the lingual artery

Examination of Nasal Cavity • It may be carried out by inserting a speculum through the external nares or by means of a mirror in the pharynx • In the latter case, the choanae and the posterior border of the septum can be visualized • A severely deviated septum may interfere with drainage of the nose and the paranasal sinuses

Trauma to the Nose • Fractures involving the nasal bones are common • Blows directed from the front may cause one or both nasal bones to be displaced downward and inward • Lateral fractures also occur in which one nasal bone is driven inward and the other outward; the nasal septum is usually involved

Infection of Nasal Cavity • Infection of the nasal cavity can spread in many of directions • Paranasal sinuses are especially prone to infection • Organisms may spread via the nasal part of the pharynx and the auditory tube to the middle ear • It is possible for organisms to ascend to the meninges of the anterior cranial fossa, along the sheaths of the olfactory nerves through the cribriform plate, and produce meningitis

Foreign Body in Nose • Foreign bodies in the nose are common in children • Presence of the nasal septum and conchae make impaction and retention of balloons, peas, and small toys

Nose Bleeding • Epistaxis, or bleeding from the nose, is a frequent condition • Most common cause is nose picking • Bleeding may be arterial or venous • Most episodes occur on the anteroinferior portion of the septum and involve the septal branches of the sphenopalatine and facial vessels

Infections of Paranasal Sinuses • Infection of the paranasal sinuses is a common complication of nasal infections • Rarely, the cause of maxillary sinusitis is extension from an apical dental abscess • The frontal, ethmoidal, and maxillary sinuses can be palpated clinically for areas of tenderness • The frontal sinus can be examined by pressing the finger upward beneath the medial end of the superior orbital margin • Here the floor of the frontal sinus is closest to the surface

Infections of Paranasal Sinuses • The ethmoidal sinuses can be palpated by pressing the finger medially against the medial wall of the orbit • The maxillary sinus can be examined for tenderness by pressing the finger against the anterior wall of the maxilla below the inferior orbital margin • Directing the beam of a flashlight either through the roof of the mouth or through the cheek in a darkened room often enable a physician to determine whether the maxillary sinus is full of inflammatory fluid rather than air

Infections of Paranasal Sinuses • Radiologic examination of the sinuses is helpful in diagnosis. One should always compare the clinical findings of each sinus on the two sides of the body • The maxillary sinus is innervated by the infraorbital nerve and, in this case, pain is referred to the upper jaw, including the teeth

Lesions of Laryngeal Nerve • Recurrent laryngeal nerves are vulnerable during operations on the thyroid gland • Left recurrent laryngeal nerve may be involved in a bronchial or esophageal carcinoma or in secondary metastatic deposits in the mediastinal lymph nodes • The right and left recurrent laryngeal nerves may be damaged by malignant involvement of the deep cervical lymph nodes

Clinical ANATOMY of Head & Neck