(Gen Ana) Pharynx

8/3/2019 (Gen Ana) Pharynx

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PharynxPharynx

Ella Chavez

Mae Nen Vedeja

Mardred Marcelo

Zara Denisse Garcia


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PharynxPharynx

The pharynx is the continuation of the

digestive system from the oral cavity.

It is a funnel-shaped fibromusculartube that is the common route for both food

and air.

The pharynx is located posterior to

the nasal and oral cavities, and the larynx.


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PharynxPharynx

The pharynx is divided into three parts: (1)

the Nasopharynx, posterior to the nose and

superior to the soft palate; (2) theOropharynx, posterior to the mouth; and

(3) the Laryngopharynx, posterior to the

larynx.

The pharynx is about 15 cm long.


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PharynxPharynx

It is widest opposite the hyoid bone and

narrowest at its inferior end, where it is

continuous with the esophagus. The posterior wall of the pharynx lies

against the prevertebral fascia with the

potential retropharyngeal space between

them.


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The Pharyngeal WallThe Pharyngeal Wall

The pharyngeal wall is composed of 5

layers. From internal to external, they are as

follows:

1.Mucous membrane: this lines the

pharynx and is continuous with all

chambers with which it communicates.


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2. Submucosa

3. Pharyngobasilar fascia: this is a fibrouslayer that is attached to the skull.

4.Muscular layer: this is composed of

inner longitudinal and outer circularparts.


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5.Buccopharyngeal fascia: This is a loose

connective tissue layer.

This fascia is continuous with the fasciacovering the buccinator and pharyngeal

muscle.

It contains the pharyngeal plexus of

nerves and veins.


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Muscles of the PharynxMuscles of the Pharynx

This consists of three constrictor muscles

and three muscles that descend from the

styloid process, the cartilaginous part of theauditory tube and the soft palate.


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External Muscles of the PharynxExternal Muscles of the Pharynx

The paired superior, middle, and inferior

constrictor muscles form the external

circular part of the muscular layer of the

wall.

These muscles overlap each other and are

arranged so that the superior one

is innermostand the inferior one

is outermost.


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These muscles contract involuntarily in a

way that results in contraction taking place

sequentially from the superior to inferior

end of the pharynx.

This action propels food into the

esophagus.


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All three constrictors of the pharynx are

supplied by the pharyngeal plexus of

nerves, which lies on the lateral wall of the

pharynx, mainly on the middle

constrictor of the pharynx.

This plexus is formed by pharyngeal

branches of the Glossopharyngeal

(IX) and Vagus (X) nerves.


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The Superior ConstrictorMuscle

Origin: pterygoid hamulus,pterygomandibular raphe, posterior endof the mylohyoid line of the mandible, andside of tongue.

Insertion: median raphe of pharynx and

pharyngeal tubercle. Innervation: through the pharyngeal

plexus of nerves.


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The pterygomandibular raphe is the

fibrous line of junction between

the buccinator and superior constrictor

muscles.


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TheMiddle ConstrictorMuscle

Origin: stylohyoid ligament and greater

and lesser horns of hyoid bone. Insertion: median raphe of pharynx.

Innervation: through the pharyngeal

plexus of nerves.


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The Inferior ConstrictorMuscle

Origin: oblique line of thyroid cartilage

and side of cricoid cartilage. Insertion: median raphe of pharynx.

Innervation: through the pharyngeal

plexus of nerves.


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The fibers arising from the cricoid

cartilage are believed to act as a sphincter,

preventing air from entering the

esophagus.


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Superior Constrictor Muscle

Middle Constrictor Muscle

Inferior Constrictor Muscle


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Gaps in the Pharyngeal MusculatureGaps in the Pharyngeal Musculature

The overlapping arrangement of the three

constrictor muscles leaves 4 deficiencies or

gaps in the pharyngeal musculature.

Various structures enter and leave the

pharynx through these gaps.


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Superior to the superior constrictor muscle,the levator veli palatini muscle, the auditorytube, and the ascending palatine arterypass

through a gap between the sup. constrictormuscle and the skull.

Superior to the superior border of thesuperior constrictor, the pharyngobasilar

fascia blends with the buccopharyngealfascia to form, with the mucous membrane, thethin wall of the pharyngeal recess.


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Between the superior and middle

constrictor muscles, the gateway to the

mouth, through which pass

the stylopharyngeal muscle,

the glossopharyngeal (IX) and the stylohyoid

ligament.


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Between the middle and inferior

constrictor muscles, the internal laryngeal

nerve and the superior laryngeal artery and

vein pass to the larynx.

Inferior to the inferior constrictor

muscles, the recurrent laryngeal

nerve and inferior laryngeal arterypasssuperiorly into the larynx.


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InternalMuscles of the PharynxInternalMuscles of the Pharynx

The internal, chiefly longitudinal muscular

layer, consists of 3 muscles:

stylopharyngeus, palatopharyngeus, and

salpingopharyngeus.

They all elevate the larynx and pharynx

during swallowing and speaking.


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The StylopharyngeusMuscle

This is a long, thin, conical muscles that

descends inferiorly between the externaland internal carotid arteries.

It enters the wall of the pharynx between

the superior and middle constrictor

muscles.


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Origin: styloid process of temporal bone.

Insertion: posterior and superior borders

of thyroid cartilage withpalatopharyngeus muscle.

Innervation: glossopharyngeal nerve (IX).

It elevates the pharynx and larynx andexpands the sides of the pharynx, thereby

aiding in pulling the pharyngeal wall over

a bolus of food.


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The PalatopharyngeusMuscle

Superior attachment: hard palate and

palatine aponeurosis. Inferior attachment: lateral wall of

pharynx.

Innervation: cranial part of accessorynerve XI) through the pharyngeal branch

of vagus (X) via the pharyngeal plexus.


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This thin, flat muscle is covered with

mucous membrane to form

the palatopharyngeal arch.

It passes posteroinferiorly in this arch.

This muscle tenses the soft palate and

pulls the walls of the pharynx superiorly,

anteriorly and medially during

swallowing.


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The SalpingopharyngeusMuscle

This is a slender muscle that descends in

the lateral wall of the pharynx. The over lying mucous membrane forms

the salpingopharyngeal fold.


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Origin: cartilaginous part of the auditorytube.

Insertion: blends with palatopharyngeusmuscle.

Innervation: through the pharyngealplexus.

It elevates the pharynx and larynx andopens the pharyngeal orifice of theauditory tube during swallowing.


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TheThe NasopharynxNasopharynx

The nasal part of the pharynx has

a respiratory function.

It lies superior to the soft palate and is aposterior extension of the nasal cavity.

The nose opens into the nasopharynx via to

large posterior apertures called choanae.


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Chonae


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In the mucous membrane of the roof of the

posterior wall of the nasopharynx is a

collection of lymphoid tissue, known as the

pharyngeal tonsil (commonly known as

the adenoids).


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The pharyngeal orifice of the auditory

tube is on the lateral wall of the

nasopharynx, 1 to 1.5 cm posterior to the

inferior concha, and level with the

superior border of the palate.

The orifice is directed inferiorly and has a

hood-like tubal elevation over it calledthe torus of the auditory tube or

the torus tubarius.


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Pharyngeal Orifice of

Auditory Tube


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The collection of lymphoid tissue in the

submucosa of the pharynx, posterior to the

orifice of the auditory tube, is known as the

tubal tonsil.

Extending inferiorly from the torus is a

vertical fold of mucous membrane, known

as the salpingopharyngeal fold.


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Posterior to the torus and the

salpingopharyngeal fold, there is a slit-like

lateral projection of the pharynx called

the pharyngeal recess.


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Pharyngeal Recess


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TheThe OropharynxOropharynx

The oral part of the pharynx has a digestive

function.

It is continuous with the oral cavity throughthe oropharyngeal isthmus (isthmus

faucium)

The oropharynx is bounded by the soft

palate superiorly, the base of the tongue

inferiorly, and the palatoglossal and

palatopharyngeal arches laterally.


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Isthmus Faucium


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HACEK organisms The name is formed from their initials:

Haemophilus

A

ctinobacillus actinomycetemcomitans Cardiobacterium hominis

Eikenella corrodens

Kingella

All of these organisms are part of the normal

oropharyngeal flora, which grow slowly, prefera carbon dioxideenriched atmosphere andshare an enhanced capacity to produceendocardial infections, especially in youngchildren.


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The Palatine Tonsils

These are usually referred to as "the tonsils".

They are collections oflymphoid tissue thatlie on each side of the oropharynx in thetriangular interval between the palatinearches.

The palatine tonsils vary in size from personto person.

In children, the palatine tonsils tend to belarge, whereas in older persons they are

usual small and inconspicuous.


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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.


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Palatine Tonsils


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TheThe LaryngopharynxLaryngopharynx

The laryngeal part of the pharynx lies

posterior to the larynx.

It extends from the superior border ofthe epiglottis to the inferior border of

the cricoid cartilage, where it narrows to

become continuous with the esophagus.

Posteriorly, the laryngopharynx is related to

the bodies of C4 to C6 vertebrae.


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TheThe LaryngopharynxLaryngopharynx

Its posterior and lateral walls are formed by

the middle and inferior constrictor muscles,

with the palatopharyngeus and

stylopharyngeus internally.

The laryngopharynx communicates with the

larynx through the aditus or inlet of the

larynx.

The piriform recess is a small, pear-shaped

depression of the laryngopharyngeal cavity

on each side of the inlet of the larynx.


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Aditus (Laryngeal inlet)


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Innervations of PharynxInnervations of Pharynx

The motor and most of the sensory supplyof the pharynx is derived from thepharyngeal plexus of nerves on the

surface of the pharynx. The plexus is formed by pharyngeal

branches of the vagus (X) andglossopharyngeal nerves (IX) nerves, andby sympatheti branches for the superiorcervical ganglion.


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Innervations of PharynxInnervations of Pharynx

The motor fibres in the pharyngeal plexus

are derived from the cranial root

of accessory nerve (XI), and are carried by

the vagus nerve to all muscles of the

pharynx and soft palate.

The exceptions are stylopharyngeus and

the tensor veli palatini.


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