Lecture #10 - Pharynx, Larynx and Sinuses

Structural significance of the pharynx

Represents the end of the upper respiratory tract

Structural significance of the larynx (according to Bragulla, since in Lee's lecture it is stated differently)

Beginning of the lower respiratory tract

Alternate name for the larynx

Voice box

Accurate description of the pharynx

Hollow organ that directly follows the nasal cavity

Define the beginning of the pharyngeal cavity

Caudal edge of the horizontal lamina of the palatine bone (also known as the bony border of the choanae)

Which muscle lines the nasopharynx?

Longus capitis muscle

Which space represents the upper cavity of the pharynx

Nasopharynx

Into which two spaces can the pharynx be divided into?

Nasopharynx and oropharynx

What forms the roof and floor of the nasopharynx?

Longus capitis muscle forms the roof, while the soft palate forms the floor

What are two muscles of importance seen in the nasopharynx?

Tensor and levator veli palatine

What is the caudal border of the soft palate connected to?

A mucosal fold known as the palatopharyngeal arch

What connects the nasopharynx and oropharynx?

Intrapharyngeal opening

What is the pharyngeal ostium of auditory tube?

Small opening in the lateral wall of the nasopharynx, connecting the pharynx to the middle ear cavity

What is an alternate name for the auditory tube, being an indicative to what it connects?

Pharyngotympanic tube

What is the functional significance of the pharyngotympanic tube?

Aids in equilibrium of the pressure in both sides of the tympanic membrane that separate the outer ear cavity and middle ear cavity

Which orifice opens during swallowing—through the action of the tensor and levator muscles of the soft palate—to allow air to enter or exit the auditory tube?

Pharyngeal ostium of auditory tube

What is rhinitis?

Inflammation of nasal mucosa

What is the clinical significance of rhinitis (or any other inflammatory process), in regards to its effects on the nasal cavity?

Rhinitis can introduce infection into the auditory tube and subsequently into the middle ear cavity, affecting hearing capacity

What are muscles of importance related to the pharynx?

Pterygophalyngeous, palatopharyngeus, hyoidpharyngeus, cricopharyngeus and thyroidpharyngeus muscles

What represents the lower "floor" of the pharynx?

Oropharynx

Define the borders of the oropharynx

Ventral to the soft palate, dorsal to the root of the tongue and rostral to the entrance of the larynx

What are structures of importance related to the oropharynx?

Hyoid apparatus and palatine tonsils

What covers the interior of the tubular structure that is the oropharynx?

Cutaneous stratified mucosa

What covers the nasopharynx internally?

Respiratory mucosa

What type of epithelium is the respiratory mucosa?

Pseudostratified epithelium, with goblet cells

What nerves are responsible for the innervation of the muscle and mucosa of the pharynx (with the exception of the tensor tympane muscle)?

Glossopharyngeal (CN IX) and vagus nerve (CN X)

Which nerve innervates the tensor tympane muscle, found in the pharynx?

Branch of the mandibular nerve, which in turn is also a branch of the trigeminal nerve (CN V)

Functional significance of the tonsils in the oropharynx (palatine tonsils)?

First line of defense against infections, considered as modifications of the mucosa and covered by mucosal folds and sinuses

What is the clinical significance of the palatine tonsils?

Objects can get stuck in its sinuses, causing local infection and inflammation

What are the laryngeal cartilages?

Forms the wall of the larynx and represent the "skeletal elements" of the larynx

What are the names of the laryngeal cartilages?

Epiglottic, laryngeal, thyroid and cricocartilage

Which laryngeal cartilage is the only that is NOT single?

Arytenoid cartilage

Which laryngeal cartilage is the only one that is NOT made of hyaline cartilage?

Epiglottic cartilage

What type of cartilage is the epiglottic cartilage made of?

Elastic cartilage

Describe: epiglottic cartilage

Defined by presence of petiolus (= stem of a leaf) and a lamina with a free edge and rostral tip

What is the functional significance of the arytenoid cartilage?

Involved in the voice box function of the larynx

Describe: the arytenoid cartilage

Triangular in shape, has various processes (muscular, articular, corniculate and cuneiform)

Describe: thyroid cartilage

Shaped like a shield and made of a single body with two lamina. Each lamina has a rostral and caudal horn

Which two muscles inserts on the thyroid cartilage?

Cricothyrod muscle and the sternothyroid muscle

Describe: cricocartilage

Has two main parts: a lamina with a muscular crest and articular processes

What type of joints is seen between the laryngeal cartilages?

True joints/synovial joints

Where is the laryngeal ventricle found?

In between the vestibular mucosal fold and the vocal mucosal fold

What is the glottis?

A narrow passageway located between the two vocal folds. It forms part of the laryngeal cavity

The entrance of the laryngeal cavity is given by which structures?

Free edge of the epiglottis, the corniculate process of the arytenoid cartilage and a mucosal fold, known as the aryepiglottic fold

What are the main parts of the laryngeal cavity?

Vestibule, glottis and cavum infraglotticum

Which part of the laryngeal cavity is covered by a respiratory mucosa?

Cavum infraglotticum

What type of mucosa covers the vestibule and the glottis of the laryngeal cavity?

Cutaneous mucosa

What are some extrinsic muscles associated with the laryngeal cartilages

Sternohyoideus muscle

What are some intrinsic muscles associated with the laryngeal cartilages

Thyroarytenoideus muscle, divided into a vestibularis muscle and a vocalis muscle

Which nerves innervate the laryngeal muscles?

Cranial and caudal laryngeal nerves (motor and sensory)

Which is the only muscle in the larynx innervated by the cranial laryngeal nerve?

Cricothyroideus muscle

What is the function of the cricoarytenoideus lateralis muscle?

Pulls arytenoid cartilage ventrally and inwards, relaxing the vocal ligament

What is the function of the cricoarytenoideus dorsalis muscle?

Pulls the arytenoid cartilage caudally and dorsally, tensing the vocal ligament and vocal fold

Is the swallowing process autonomic or voluntary?

Autonomic

Which nerves are responsible for initiating the actions of peristalsis, once receptors in the soft palate are stimulated by the bolus?

Cranial nerves IX and X

What is the piriform recess?

Anatomical depression in the laryngopharynx that channels food around the laryngeal opening.

How can knowledge of the pharynx, larynx and its associated structures be applied clinically?

Use of nasogastric tubes and tracheal tubes (used during surgery)