The Oropharynx

• The oral part of the pharynx has a digestive function.
• It is continuous with the oral cavity through the oropharyngeal isthmus.
• The oropharynx is bounded by the soft palate superiorly, the base of the tongue inferiorly, and the palatoglossal and palatopharyngeal arches laterally.

• It extends from the soft palate to the superior border of the epiglottis.

The Palatine Tonsils

• These are usually referred to as "the tonsils".
• They are collections of lymphoid tissue the lie on each side of the oropharynx in the triangular interval between the palatine arches.

• The palatine tonsils vary in size from person to person.
• In children, the palatine tonsils tend to be large, whereas in older persons they are usual small and inconspicuous.
• The visible part of the tonsil is no guide to its actual size because much of it may be hidden by the tongue and buried in the soft palate.

Classified on functional Basis

Secretion ,Protection and waterproofing, Absorbtion, Transport, Sensory

Secretion

Glandular epithelium’s 3 types:

- Exocrine - with ducts

- endocrine - without ducts

- mixed exo-endocrine

Exocrine glands: One cell

- goblet cells

- In lining epitheliums of respiratory tract and GIT

- Secretes musin (protein) Musin + water = mucus, Mucus is a lubricant

More than one cell

 Simple:  Has a single duct,

• Acinar - mucus glands of the penile urethra
• Tubular - cripts of Lieberkuhn
• Coiled tubular - sweat gland
• Spiral tubular - Gland of Moll
• Branched tubular - mucous glands of the pyloric region
• Branched acinar - sebaceous gland in the skin

Compound

• Consists of a branched duct with numerous secretory end organs
• Compound tubular - Brünners glands
• Compound alveolar - mammary, prostate, pancreas, parotid
• Compound tubuloalveolar - submandibular-, sublingual salivary glands

Endocrine glands

Secrete directly into the blood

One cell :  mast cells,  in soft CT,  near capillaries,

secrete - heparin - histamine

More than one cell

Cells can be arranged in the following ways:

• Cords - adrenal glands, parathyroid, anterior pituitary
• anastomosing cords with dilated blood capillaries in-between
• Isles - pancreas
• Follicles - thyroid
• cells line a follicle filled with non-cellular material

Movements of the Temporomandibular Joint

• The two movements that occur at this joint are anterior gliding and a hinge-like rotation.
• When the mandible is depressed during opening of the mouth, the head of the mandible and articular disc move anteriorly on the articular surface until the head lies inferior to the articular tubercle.

• As this anterior gliding occurs, the head of the mandible rotates on the inferior surface of the articular disc.
• This permits simple chewing or grinding movements over a small range.

• Movements that are seen in this joint are: depression, elevation, protrusion, retraction and grinding

The Lateral Pterygoid Muscle

• This is a short, thick muscle that has two heads or origin.
• It is a conical muscle with its apex pointing posteriorly.

• Origin: superior head—infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone, inferior head—lateral surface of lateral pterygoid plate.
• Insertion: neck of mandible, articular disc, and capsule of temporomandibular joint.
• Innervation: mandibular nerve via lateral pterygoid nerve from anterior trunk, which enters it deep surface.

• Acting together, these muscles protrude the mandible and depress the chin.
• Acting alone and alternately, they produce side-to-side movements of the mandible.

Geniohyoid Muscle

• Origin: Inferior genial tubercles of the mandible.
• Insertion: Anterior surface of the body of the hyoid bone.
• Nerve Supply: Branch of C1 through the hypoglossal nerve (CN XII).
• Arterial Supply: Sublingual branch of the lingual artery.
• Action: Elevates the hyoid bone and depresses the mandible.

Muscles Moving the Auditory Ossicles

The Tensor Tympani Muscle

• This muscle is about 2 cm long.

• Origin: superior surface of the cartilaginous part of the auditory tube, the greater wing of the sphenoid bone, and the petrous part of the temporal bone.
• Insertion: handle of the malleus.
• Innervation: mandibular nerve (CN V³) through the nerve to medial pterygoid.

• The tensor tympani muscle pulls the handle of the malleus medially, tensing the tympanic membrane, and reducing the amplitude of its oscillations.
• This tends to prevent damage to the internal ear when one is exposed to load sounds.

The Stapedius Muscle

• This tiny muscle is in the pyramidal eminence or the pyramid.

• Origin: pyramidal eminence on the posterior wall of the tympanic cavity. Its tendon enters the tympanic cavity by traversing a pinpoint foramen in the apex of the pyramid.
• Insertion: neck of the stapes.
• Innervation: nerve to the stapedius muscle, which arises from the facial nerve (CN VII).

• The stapedius muscle pulls the stapes posteriorly and tilts its base in the fenestra vestibuli or oval window, thereby tightening the anular ligament and reducing the oscillatory range.
• It also prevents excessive movement of the stapes.