Transcript The Head & Neck - Karbala Medical College / Anatomy

Clinical & Applied Anatomy
Head & Neck Unit – Lecture 16
‫ حيدر جليل األعسم‬.‫د‬
Lecture 1&2: Skull
Fractures of the Skull
•Fractures of Pterion may lead to injury of anterior division of middle
meningeal arteries, thus leading to epi-cranial or extradural
haematoma. It usually affects level of consciousness then a re-gain of
consciousness occur that called Lucid Period. Continuous increasing
haematoma leads to deteriorating level of consciousness and may lead
to cerebral compression, brain stem herniation and /or death.
•Fractures of cribriform plate of ethmoid bone may result in tearing of
meninges. The patient will have bleeding from nose (epistaxis) and
leakage of cerebrospinal fluid into the nose (CSF rhinorrhea).
•Fracture of the base of the skull results in passage of blood through
superior and inferior orbital fissure to accumulate around the eyes. This
lead to typical appearance of bilateral black eyes (Panda Eyes).
•Fracture of the floor of the orbit due to severe blow to the orbit may
cause contents of orbital cavity to pass through floor of orbit into
maxillary sinus, leading to damage to infraorbital nerve (altered
sensation to skin of cheek, upper lip & gum) & lower rectus muscle may
get entrapped in between fractured bones leading to squint.
Lecture 3: Meninges
Intracranial Hemorrhage: result from trauma or cerebral vascular
lesion.
• Extradural hemorrhage: results from injuries to meningeal
arteries or veins. Most common artery to be damaged is middle
meningeal artery by a minor blow to side of the head, resulting in
fracture of Pterion.
• Subdural hemorrhage: results from tearing of superior cerebral
veins at their point of entrance into superior sagittal sinus due to
a blow on front or back of head. Blood under low pressure begins
to accumulate in potential space between dura and arachnoid.
• Subarachnoid hemorrhage: results from leakage or rupture of a
congenital aneurysm on circle of Willis or from an angioma.
There will be sudden severe headache, stiffness of neck & loss of
consciousness. Diagnosis is established by aspirating bloodstained CSF through a lumbar puncture (spinal tap).
• Cerebral hemorrhage: is generally caused by rupture of thinwalled branch of middle cerebral artery, thus involving a vital
fibers in internal capsule and produces hemiplegia on opposite
side of the body. Patient immediately loses consciousness, and
paralysis is noted when consciousness is regained.
Lecture 4: Scalp
Lacerations of the Scalp:
Scalp has a profuse blood supply and arterial walls are
attached to fibrous septa in subcutaneous tissue (unable
to contract or retract after injury), thus a small laceration
of scalp can cause severe blood loss and it is difficult to
stop the bleeding of a scalp wound.
Scalp Infections:
Infections of scalp tend to remain localized and are
usually painful because of abundant fibrous tissue in the
subcutaneous layer. Occasionally, an infection of scalp
spreads by emissary veins, which are valveless, to the
skull bones, causing osteomyelitis or may travel farther
into venous sinuses and produce venous sinus
thrombosis.
Lecture 5: Face
Facial Infections and Cavernous Sinus Thrombosis:
Area of facial skin bounded by nose, eye, and upper lip is a dangerous
zone for infection. A boil in this region can cause thrombosis of facial
vein which my spread through inferior ophthalmic veins to cavernous
sinus, resulting in cavernous sinus thrombosis that may be fatal.
Facial Muscle Paralysis:
Damage to facial nerve in internal acoustic meatus (by a tumor), in
middle ear (by infection), in facial canal (perineuritis, Bell's palsy), or in
parotid gland (by a tumor) will cause paralysis of facial muscles and
distortion of face, with drooping of lower eyelid and mouth will deviated
to normal side. This is essentially a lower motor neuron lesion. An upper
motor neuron lesion will leave upper part of the face normal
Testing the Integrity of the Facial Nerve
Facial nerve supplies muscles of facial expression; anterior 2/3 of tongue
with taste fibers; and is secretomotor to lacrimal, submandibular, and
sublingual glands. To test motor facial nerve, patient is asked to show
teeth by separating lips with teeth clenched, and then to close the eyes.
Facial Artery pulsation:
Pulsations of facial artery can be felt at lower margin of body of
mandible at anterior border of masseter muscle.
Lecture 6: Temporal Region
Dislocation of Temporomandibular Joint:
It may occur when mandible is
depressed because the joint is
unstable. A minor blow on the
chin or a sudden contraction of
lateral pterygoid muscles (as in
yawning) may be sufficient to pull
head of mandible and articular
disc beyond the summit of
articular tubercle. In bilateral
cases, mouth is fixed in an open
position, and both heads of the
mandible lie in front of the
articular tubercles.
Lecture 7: Orbit & Eye
Pupillary Reflexes: are reactions of pupils to light & accommodation.
Direct light reflex: normal pupil reflexly contracts when a light is shone
into patient's eye. Nerve impulses pass through Retina - optic nerve optic chiasma - optic tract - lateral geniculate body where fibers
concerned with this reflex leave and pass to oculomotor nuclei on both
sides. Then efferent fibers leave midbrain in oculomotor nerve and reach
ciliary ganglion via nerve to inferior oblique. Postganglionic fibers pass to
constrictor pupillae muscles via short ciliary nerves.
Indirect (consensual) light reflex: is contraction of pupil in one eye in
response to shining light in opposite eye. This reflex is possible because
afferent pathway travels to nuclei of both oculomotor nerves.
Accommodation reflex is the contraction of pupil that occurs when a
person suddenly focuses on a near object after having focused on a
distant object. Nerve impulses pass through Retina - optic nerve - optic
chiasma - optic tract - lateral geniculate body - optic radiation - cerebral
cortex. Visual cortex is connected to the eye field of frontal cortex which
send efferent impulses to oculomotor nucleus that reach constrictor
pupillae via oculomotor nerve, ciliary ganglion, and short ciliary nerves.
Lecture 8: Ear
Otitis Media & Complications:
Pathogenic organisms can gain entrance to middle ear
by ascending through auditory tube from naopharynx.
Otitis Media is the acute infection of middle ear and
produces bulging and redness of tympanic
membrane. Inadequate treatment of otitis media can
result in spread of infection into mastoid antrum and
mastoid air cells (acute mastoiditis). Acute mastoiditis
may be followed by further spread of organisms
beyond boundaries of middle ear. Spread of infection
in superior direction could produce meningitis &
cerebral abscess in temporal lobe. Spread of infection
in medial direction can cause a facial nerve palsy &
labyrinthitis with vertigo. If infection spreads in
posterior direction, Thrombosis in sigmoid sinus may
occur.
Lecture 9: Nose & Paranasal sinuses
Infection of the Nasal Cavity:
Infection of nasal cavity can spread in a variety of directions.
Paranasal sinuses are especially prone to infection (Sinusitis).
Organisms may spread via nasopharynx & auditory tube to
middle ear. It may ascend to meninges of anterior cranial
fossa along sheaths of olfactory nerves through cribriform
plate & produce meningitis.
Nose Bleeding (Epistaxis):
Epistaxis, or bleeding from nose, is a frequent condition
caused most commonly by nose picking. Bleeding may be
arterial or venous, and most episodes occur on anteroinferior
portion of septum and involve septal branches of
sphenopalatine and facial vessels.
Lecture 10: Oral cavity & Salivary Glands
Parotid Salivary Gland and Lesions of Facial Nerve:
Facial nerve lies in interval between superficial & deep parts of parotid
gland. Malignant tumour usually involves facial nerve, causing unilateral
facial paralysis while benign tumours rarely cause facial palsy.
Parotid Gland Infections:
Parotid gland may become acutely inflamed as a result of retrograde
bacterial infection from mouth via parotid duct or via bloodstream, as in
Mumps. In both, gland is swollen and painful because capsule is strong
and limits swelling of the gland. Swollen glenoid process, which extends
medially behind TMJ, causes pain when eating.
Submandibular Salivary Gland: Calculus Formation:
Submandibular gland is a common site of calculus formation which is
rare in other salivary glands. Tense swelling below the mandible before
or during meals and absence of swelling between meals, is diagnostic of
this condition. Frequently, stone can be palpated in the duct, which lies
below mucous membrane of the floor of mouth.
Sublingual Salivary Gland and Cyst Formation:
Sublingual salivary gland, which lies beneath sublingual fold of floor of
mouth, opens into mouth by numerous small ducts. Blockage of one of
these ducts is believed to be cause of cysts under the tongue.
Lecture 11&12: Neck Triangles
Congenital Torticollis
Congenital torticollis is a result of excessive stretching of
sternocleidomastoid muscle during a difficult labour. Hemorrhage
occurs into the muscle and may be detected as a small, rounded tumour
during early weeks after birth. Later, it is replaced by fibrous tissue,
which contracts and shortens the muscle pulling mastoid process down
toward sternoclavicular joint. Thus, cervical spine is flexed and face looks
upward to opposite side. If left untreated, asymmetrical growth changes
occur in face, and cervical vertebrae may become wedge shaped.
Spasmodic Torticollis:
Spasmodic torticollis results from repeated chronic contractions of
sternocleidomastoid and trapezius muscles and is usually psychogenic.
Section of spinal part of accessory nerve may be needed in severe cases.
External Jugular Vein Catheterization:
External jugular vein is superficial valved vein that can be used for
venous catheterization because it is in most direct line with superior
vena cava. It is catheterized about halfway between level of cricoid
cartilage and clavicle. Catheter should be inserted during inspiration?
Lecture 11&12: Thyroid Gland
Swellings of Thyroid Gland and Movement on Swallowing:
Thyroid gland is invested in a sheath derived from pretracheal fascia.
This tethers gland to larynx & trachea and explains why thyroid gland
follows movements of larynx in swallowing. Any thyroid swelling will
move upward when the patient is asked to swallow.
Retrosternal Goiter:
Sternothyroid muscles to thyroid cartilage limits upward expansion of
thyroid gland; thus sometimes enlarged thyroid gland extend downward
behind sternum (Retrosternal goiter). It can compress trachea & causes
dangerous dyspnea; it can also cause severe venous compression.
Thyroid Arteries and Important Nerves:
The two main arteries supplying thyroid gland are closely related to
important nerves that can be damaged during thyroid operations.
Superior thyroid artery on each side is related to external laryngeal
nerve, which supplies cricothyroid muscle. Terminal branches of inferior
thyroid artery on each side are related to recurrent laryngeal nerve.
External laryngeal nerve damage results in hoarseness of voice because?
Thyroidectomy and the Parathyroid Glands:
Parathyroid glands are usually 4 in number & closely related to posterior
surface of thyroid gland. In partial thyroidectomy, posterior part of
thyroid gland is left undisturbed, so parathyroid glands are not damaged
Lecture 13: Pharynx
Quinsy:
It is peritonsillar abscess caused by spread of infection from palatine
tonsil to loose connective tissue outside capsule of the tonsil.
Adenoids: is excessive hypertrophy of pharyngeal tonsils usually
associated with infection. They blocks the posterior nasal openings and
causes the patient to snore loudly at night and to breathe through open
mouth. It may cause recurrent otitis media and deafness because of the
close relationship of infected lymphoid tissue to auditory tube.
Adenoidectomy is treatment for hypertrophied adenoids with infection.
Piriform Fossa and Foreign Bodies
Piriform fossa is a common site for lodging of sharp ingested bodies such
as fish bones. This causes the patient to gag violently. It sometimes
needs physician's assistance when the object has become jammed.
Lecture 14: Larynx
Lesions of the Laryngeal Nerves:
Muscles of larynx are innervated by recurrent laryngeal nerves except
cricothyroid which is supplied by external laryngeal nerve. Both these nerves
are vulnerable during thyroid operations. Left recurrent laryngeal nerve may be
involved in a bronchial or esophageal carcinoma or in secondary metastatic
deposits in mediastinal lymph nodes.
Section of external laryngeal nerve causes weakness of voice because vocal
fold can’t be tensed as cricothyroid muscle is paralyzed.
Unilateral complete section of recurrent laryngeal nerve results in vocal fold
on affected side assuming position midway between abduction and adduction.
It lies lateral to midline but speech is not greatly affected because other vocal
fold compensates to some extent and moves toward affected vocal fold.
Bilateral complete section of recurrent laryngeal nerve results in both vocal
folds assuming position midway between abduction and adduction. Breathing
is impaired because rima glottidis is partially closed & speech is lost.
Unilateral partial section of recurrent laryngeal nerve results in a greater
degree of paralysis of abductor muscles than of adductor muscles. Affected
vocal fold assumes adducted midline position.
Bilateral partial section of recurrent laryngeal nerve results in bilateral
paralysis of abductor muscles and drawing together of vocal folds. Acute
breathlessness (dyspnea) and stridor follow and tracheostomy is necessary.
Lecture 15: Root of the Neck
Supraclavicular Approach of Subclavian vein catheterisation: Preffered
1. Site of penetration of vein wall is larger.
2. Needle is pointed downward & medially toward mediastinum.
3. Catheter is inserted along more direct course into brachiocephalic v.
With patient in supine position with head tilted downward or simple
supine position and head turned to opposite side. Needle is inserted
through skin at site where posterior border of clavicular origin of
sternocleidomastoid is attached to upper border of clavicle. At this
point, needle lies lateral to lateral border of scalenus anterior muscle
and above first rib. Needle is directed downward in direction of opposite
nipple and pierces the following structures:
1. Skin
2. Superficial fascia and platysma
3. Investing layer of deep cervical fascia
4. Wall of the subclavian vein
Possible Complications:
1. Paralysis of diaphragm: if injury to phrenic nerve occurs.
2. Pneumothorax or hemothorax:
3. Brachial plexus injury: if injured by needle passing posteriorly into the
roots or trunks of the plexus.
End of the Lecture
GOOD LUCK