Head and Neck

is the bony covering (case) of the brain and its membranous coverings, the cranial meninges. It also contains the proximal parts of the cranial nerves and the vasculature of the brain. The neurocranium has a dome-like roof, the calvaria (skullcap), and a floor or cranial base (basicranium).

four singular bones centered on the midline (frontal, ethmoid, sphenoid, and occipital) and two sets of bones occurring as bilateral pairs (temporal and parietal). Most calvarial bones are united by fibrous interlocking sutures; however, during childhood, some bones (sphenoid and occipital) are united by hyaline cartilage (synchondroses).

made up of the facial bones that mainly develop in the mesenchyme of the embryonic pharyngeal arches. The viscerocranium forms the anterior part of the cranium and consists of bones surrounding the mouth, nose, and most of the orbits

three singular bones lying in the midline (mandible, ethmoid, and vomer) and six paired bones occurring bilaterally (maxilla; inferior nasal concha; and zygomatic, palatine, nasal, and lacrimal bones).

• b. Floor: Maxilla (some: zygomatic, palatine)
• c. Lateral wall: Zygomatic bone (frontal process) and the Greater Wing of the Sphenoid
• d. Medial wall: Ethmoid (some: frontal, lacrimal, sphenoid)

To the skull, Styloid Process: stylohyoid muscle

• the maxillary sinus is under the middle concha
• inferior? superior?

Temporal (inferiorly)

Nuchal Lines

CN V2 Maxillary Nerve

CN V3 Mandibular Nerve, accessory meningeal artery

CN V3 meningial branch, Middle meningeal artery and vein

nothing

Medulla, meninges, vertebral arteries, CN XI, dural veins, anterior/posterior spinal arteries

CN IX, X, XI, IJV, inferior petrosal & sigmoid sinuses, meningeal branches of pharyngeal and occipital arteries

CN VII

Internal Carotid Artery

CN II

CN I

• Ventricles: Lateral, 3rd, 4th. The 3rd and 4th are connected via the Cerebral Aqueduct.
• Choroid Plexus produces CSF. Choroid Plexus is found in the ventricles.

• -Lacrimal ducts convey lacrimal fluid from the lacrimal glands to the conjunctival sac.
• -Lacrimal canaliculi (L. small canals), each commencing at a lacrimal punctum (opening) on the lacrimal papilla near the medial angle of the eye, convey the lacrimal fluid from the lacrimal lake to the lacrimal sac, the dilated superior part of the nasolacrimal duct
• -Nasolacrimal duct conveys the lacrimal fluid to the nasal cavity.
• -The almond-shaped lacrimal gland lies in the fossa for the lacrimal gland in the superolateral part of each orbit.

• Masseter: Elevates Mandible
• Lateral Pterygoid: bilateral: Protracts mandible, depress chin, unilateral: swings jaw
• Medial Pterygoid: contributes to protrusion, synergistic action, unilateral: grinding

Innervation by CN VII (7)

Frontal

The salivary glands include the parotid, submandibular, and sublingual glands.

the largest of the major salivary glands. Each parotid gland has an irregular shape because it occupies the gap between the ramus of the mandible and the styloid and mastoid processes of the temporal bone. The purely serous secretion of the gland passes through the parotid duct and empties into the vestibule of the oral cavity opposite the second maxillary molar tooth.

lie along the body of the mandible, partly superior and partly inferior to the posterior half of the mandible and partly superficial and partly deep to the mylohyoid muscle. The orifices of the submandibular ducts are visible, and saliva often sprays from it when the tongue is elevated and retracted (as when yawning). The sublingual glands are the smallest and lie in the floor of the mouth between the mandible and the genioglossus muscle. The sublingual ducts open into the floor of the mouth alongside the lingual folds.

Vallate papillae are large and flat topped; they lie directly anterior to the terminal groove and are surrounded by deep moat-like trenches, the walls of which are studded by taste buds; the ducts of serous lingual glands (of von Ebner) open into these trenches.

are small lateral folds of lingual mucosa; they are poorly developed in humans.

are long, numerous, thread-like and scaly; they contain afferent nerve endings that are sensitive to touch.

are mushroom-shaped and appear as pink or red spots; they are scattered among the filiform papillae but are most numerous at the apex and sides (margins) of the tongue.

The vallate, foliate, and most of the fungiform papillae contain taste receptors in the taste buds. A few taste buds are also in the epithelium covering the oral surface of the soft palate, the posterior wall of the oropharynx, and the epiglottis.

These come from the Vertebral Arteries then Basilar: Posterior Cerebral, Posterior Communicating, Internal Carotid, Anterior Cerebral and Anterior Communicating Arteries

• Posteriorly and superiorly by the superior and inferior temporal lines. Anteriorly by the frontal and zygomatic bones.Laterally by the zygomatic arch. Inferiorly by the infratemporal crest.
• The floor of the temporal fossa is formed by parts of the four bones (frontal, parietal, temporal, and greater wing of the sphenoid) that form the pterion. The fan-shaped temporal muscle arises from the bony floor and the overlying temporal fascia, which makes up the roof of the temporal fossa (Fig. 7.24; Table 7.8). The temporal fascia extends from the superior temporal line to the zygomatic arch. When the powerful masseter, attached to the inferior border of the arch, contracts and exerts a strong downward pull on the arch, the temporal fascia provides resistance

Pterion: H shaped formation of sutures that unites the frontal, parietal, sphenoid (Greater Wing) and temporal bones

are endothelial-lined spaces between the periosteal and meningeal layers of the dura

lies in the convex attached (superior) border of the cerebral falx. It begins at the crista galli and ends near the internal occipital protuberance at the confluence of sinuses. The superior sagittal sinus receives the superior cerebral veins and communicates on each side through slit-like openings with the lateral venous lacunae, lateral expansions of the superior sagittal sinus.

much smaller than the superior sagittal sinus, runs in the inferior, free concave border of the cerebral falx and ends in the straight sinus.

formed by the union of the inferior sagittal sinus with the great cerebral vein. It runs inferoposteriorly along the line of attachment of the cerebral falx to the cerebellar tentorium to join the confluence of sinuses.

pass laterally from the confluence of sinuses in the posterior attached margin of the cerebellar tentorium, grooving the occipital bones and the posteroinferior angles of the parietal bones. The transverse sinuses leave the cerebellar tentorium at the posterior aspect of the petrous temporal bone and become the sigmoid sinuses.

follow S-shaped courses in the posterior cranial fossa, forming deep grooves in the temporal and occipital bones. Each sigmoid sinus turns anteriorly and then continues inferiorly as the internal jugular vein (IJV) after transversing the jugular foramen.

lies in the attached border of the cerebellar falx and ends superiorly in the confluence of sinuses. The occipital sinus communicates inferiorly with the internal vertebral venous plexus.

Sympathetic: Catabolic, fight (fight or flight)

• Anterior boundary: formed by the median line of the neck.
• Posterior boundary: formed by the anterior border of the SCM.
• Superior boundary: formed by the inferior border of the mandible.
• Apex: located at the jugular notch in the manubrium of the sternum.
• Roof: formed by subcutaneous tissue containing the platysma.
• Floor: formed by the pharynx, larynx, and thyroid gland.

• The broad SCM is the key muscular landmark of the neck. It defines the sternocleidomastoid region and divides the neck into anterior and lateral cervical regions. It is easy to observe and palpate throughout its length as it passes superolaterally from the clavicle and manubrium to the mastoid process of the temporal bone. The SCM can be made to stand out by asking the person to rotate the face toward the contralateral side and elevate the chin.
• The EJV runs vertically across the SCM toward the angle of the mandible. This vein may be prominent, especially if distended by asking the person to take a deep breath (Valsalva maneuver). The jugular notch in the manubrium is the fossa between the sternal heads of the SCM. The lesser supraclavicular fossa, between the sternal and the
• clavicular heads of the SCM, overlies the inferior end of the IJV. Deep to the superior half of the SCM is the cervical plexus, and deep to the inferior half of the SCM are the IJV, common carotid artery, and vagus nerve in the carotid sheath. The trapezius, which defines the posterior cervical region, can be observed and palpated by asking the person to shrug the shoulders against resistance.
• Just inferior to the belly of the omohyoid is the greater supraclavicular fossa, the depression overlying the omoclavicular triangle. The subclavian arterial pulsations can be palpated here in most people. The occipital triangle contains the spinal accessory nerve (CN XI). Because of its vulnerability and frequency of iatrogenic injury (damage resulting from medical treatment), it is important to be able to estimate the location of the nerve. Its course can be approximated by a line that intersects the junction of the superior and middle thirds of the posterior border of the SCM and the junction of the middle and lower thirds of the anterior border of the trapezius. The submandibular gland nearly fills the submandibular triangle. The submandibular lymph nodes lie superficial to the gland and, if enlarged, can be palpated by moving the fingers from the angle of the mandible along its inferior border. If continued until the fingers meet under the chin, enlarged submental lymph nodes can be palpated in the submental triangle. The carotid arterial system is located in the carotid triangle. The carotid sheath can be mapped out by a line joining the sternoclavicular joint to a point midway between the mastoid process and the angle of the mandible. The carotid pulse can be palpated by placing the index and 3rd fingers on the thyroid cartilage and pointing them posterolaterally between the trachea and SCM. The pulse is palpable just medial to the SCM muscle.

• Carotid Body: Innervated by CN IX and CN X, function: chemoreceptor, monitors the level of oxygen in the blood
• Carotid Sinus: Innervated by CNIX and CN X, function: baroreceptor, reacts to changes in blood pressure

Endocrine, Respiratory and Alimentary

Head: Pituitary, Pineal; Neck: Thyroid, Parathyroid. A system of glands, each of which secretes a type of hormone to regulate the body

9 cartilages in the Laryngeal Skeleton: Thyroid, Cricoid, Epiglottic, Arytenoid (paired), Corniculate (paired) & Cuneiform (paired)

Trachealis Muscle

The trachea terminates at the level of the sternal angle into a right and left Primary Bronchi.

Palatine Tonsils: lie in the tonsilar sinus between the palatoglossal and palatopharyngeal arches.

Tubal Tonsil: located in the submucosa pharynx near the pharyngeal oriface of the pharyngotympanic tube

unevenly divided and separated by a bony septum, occupy the body of the sphenoid bone; they may extend into the wings of this bone in the elderly. Because of these sinuses, the body of the sphenoid is fragile. Only thin plates of bone separate the sinuses from several important structures: the optic nerves and optic chiasm, the pituitary gland, the internal carotid arteries, and the cavernous sinuses. The posterior ethmoidal artery and nerve supply the sphenoidal sinuses.

are the largest of the paranasal sinuses. These large pyramidal cavities occupy the bodies of the maxillae. The apex of the maxillary sinus extends toward and often into the zygomatic bone. The base of the maxillary sinus forms the inferior part of the lateral wall of the nasal cavity. The roof of the maxillary sinus is formed by the floor of the orbit. The floor of the maxillary sinus is formed by the alveolar part of the maxilla. The roots of the maxillary teeth, particularly the first two molars, often produce conical elevations in the floor of the maxillary sinus. Each sinus drains by an opening, the maxillary ostium, into the middle meatus of the nasal cavity via the semilunar hiatus. Because of the superior location of this opening, it is impossible for the sinus to drain when the head is erect until the sinus is full. The arterial supply of the maxillary sinus is mainly from superior alveolar branches of the maxillary artery; however, branches of the greater palatine artery supply the floor. Innervation of the maxillary sinus is from the anterior, middle, and posterior superior alveolar nerves branches of CN V2.

Ptosis: to droop, in the case of an eye, the upper lid droops.

• Function: Origin of the rectus muscles of the eye.
• Location: Surrounding the optic canal and part of the superior orbital fissure.

• Superior Oblique innervated by CN IV
• Inferior Oblique innervated by CN III
• Superior and Inferior Rectus innervated by CN III
• Medial and Lateral Rectus innervated by CN VI

The aqueous humor drains into the scleral venous sinus, canal of Schlemm at the iridocorneal angle. The aqueous humor is removed by the limbal plexus, a network of scleral veins close to the limbus, which drain, in turn, into both tributaries of the vorticose and anterior ciliary veins.

Extraocular muscles of the orbit, bulbar fascia

Fibrous layer (outer coat) consisting of the sclera and cornea.Vascular layer (middle coat), consisting of the choroid, the ciliary body, and the iris. Inner layer (inner coat), consisting of the retina, which has both optic and non-visual parts

CN V, CN IX, CN X

Middle ear cavity

It is buried in the Petrous part of the Temporal bone

• Also known as the Pharyngotympanic Tube or Eustachian Tube.
• It serves as a connection between the tympanic cavity (middle
• ear) and the nasopharynx.

Cochlea

Chordae Tympani branch of Cranial Nerve VII (7)

b. Cochlea (sound)

c. Semicircular Canal and Duct (balance).

Found in the following order: Mallus, Incus and Stapes.

• Remember:
• S Skin
• C Connective Tissue
• A Aponeurosis
• L Loose Connective Tissue
• P Periosteum