311 (Session 7) Anatomy of the tongue, salivary glands, pharynx, and esophagus

What CNs are responsible for general sensation of the tongue

Anterior 2/3 = CN V3

Posterior 1/3 = CN IX

What CNs are responsible for taste of the tongue

Anterior 2/3 = CN VII

Posterior 1/3 = CN IX

Which CN is the main motor innervation of the tongue

CN XII

• Except Palatoglossus = CN X

What are the extrinsic muscles of the tongue

Genioglossus

Hypoglossus

Styloglossus

Palatoglossus

What are the intrinsic muscles of the tongue

1. Superior Longitudinal

2. Inferior longitudinal

3. Transverse

4. Vertical

Extrinsic muscles of tongue function

Protrude + Retract

Elevate + depress

intrinsic muscle tongue movement

Shorten / curl

Narrow / elongate

Flatten / broaden

What would result from a CN VII deficit in terms of tongue innnervaiton

Reduced / lost taste form anterior 2/3, but general sensation remains the same

What would result from a CN V3 deficit in terms of tongue innnervaiton

Reduced / lost general sensation from anterior 2/3 of tongue

What would result from a CN IX deficit in terms of tongue innnervaiton

Reduced/lost general sensation AND taste from posterior 1/3

What would result from a CN XII deficit in terms of tongue innnervaiton

Impaired tongue movement

What are the three main pairs of salivary glands

1. Parotid (biggest)

2. Submandibular

3. Sublingual

What is the function of salivary glands

Secrete saliva into oral cavity

• Lubricates food

• Starts digestion of starch

Which muscle does the parotid gland sit on

• Masseter muscle

• Retromandibular fossa (Most of it)

• Extermal acoustic meatus

What sheath is the parotid gland surrounded by

Parotid Sheath

How does saliva get transfered from the parotid gland to the oral cavity

Parotid duct

What nerve innervates the parotid gland

CN 9

Which CN provides the parasympathetic / secretomotor supply to the motor gland

Glossopharyngeal nerve (CN 9)

What is the sympathetic innervation of the parotid gland

Sympathetic: Superior cervical ganglion → external carotid plexus

Compare and contrast parasympathetic vs sympathetic innervation FUNCTION on the parotid gland

Parasympathetic: stimulates saliva

Sympathetic: Reduces saliva

How is saliva transfered from the submandibular gland to the oral cavity

Submandibular duct

Which structure does the sublingual gland lie between

Mandible and the Genioglossus muscle

What structures does the sublingual duct work and communicate with

• Submandibular duct

• lingual nerve (Branch of CN V3)

What is the parasympathetic innervation the sublingual and submandibular glands

CN 7

What is the sympatetic innervation the sublingual and submandibular glands

Sympathetic: Superior Cervical ganglion → external carotid

What are the three layers of the cervical viscera

1. Endocrine layer: Thyroid & Parathyroid Glands

2. Respiratory layer: Larynx & Trachea

3. Alimentary layer: Pharynx & Esophagus

Which layer of the cervical viscera is this

Endocrine layer: Thyroid and Parathyroid

Which layer of the cervical viscera is this?

Respiratory Layer (larynx and trachea)

Which layer of the cervical viscera is this

Alimentary Layer: Pharynx and Esophagus

What are the three layers of the pharynx

What is the nasopharynx

• 1/3 of the pharynx

• Posterior extension of the nasal cavity

• Communicates with the nose through Choanae (two openings)

How does the nasopharynx communicate with the nose

Through two openings called Choanae

What structure connects the nasopharynx to the tympanic cavity

Pharyngotympanic tube

Name this structure and its funciton

Salpingopharyngeus

• raises pharynx while swallowing

• Opens pharyngeal orifice of pharyngotympanic tube

Pharynx contains lymphoid tissue called what

Tonsils

Name the following structures

What separates the oropharynx and the oral cavity

Palatoglossal Arch

Name the following structures

Identify the following structures? and what do all these structures form

Which tonsils make up the anterior inferior part of the waldeyer ring

Lingual Tonsils

Which tonsils make up the LATERAL part of the waldeyer ring

Palatine and Tubal tonsils

Which tonsils make up the posterior inferior part of the waldeyer ring

Pharyngeal Tonsil

Laryngopharynx extends from ______ and _____ to ______

Extends form superior border of epiglottis and pharyngeoepiglottic folds to inferior border of cricoid cartilage

How does the laryngopharynx communicate with the larynx

Via the laryngeal inlet

Label

What must happen to the soft paalt during swallowing, and what would happen if it did not?

During swallong, the soft palate elevates superiorly and posteriorly to close off the nasopharynx, preventing food or liquid from moving superiorly into the nasal cavity. If it did not elevate preoperly, food or liquid could pass superiorly into the nasopharynx and nasal cavity, causing nasal regurgitation

What is the pahryngeal constirctors

Trio of circular skeletal muscle that form the outer msucular wall of the pharynx and contract to push food down into the esophagus

Superior consitrictor

Middle pharyngeal

Inferior pharyngeal

identify these structures

The Pharyngeal constirctors

How do the pharyngeal constrictors move a bolus?

The superior, middle, inferior pharyngeal constrictors contract sequentially, creating a wave that pushes the bolus inferiorly thorugh the pharynx toward the eosophagus

 How do the suprahyoid and infrahyoid groups contribute to movement and stabilization of the hyoid–laryngeal complex during swallowing?

Suprahyoid muscle: Pull the hyoid and larynx superiorly and anteriorly during swallowing. This protects the airway and assists with opening the upper esophageal sphincter so the bolus can pass

Infrahyoid muscle: Mainly stabilize the hyoid and, after the swallow, help pull the hyoid and larynx back toward their resting position.

Label this diagram

What are the broad sesnory and motor roles of CN IX and X in this region for the pharynx during swallowing

CN IX: mainly sensory → detects touch/bolus in the oropharynx and helps trigger the swallowing reflex

CN X: mainly motor → provides motor innervation to most pharyngeal muscles (pharyngeal contrictors)

The nasopharynx extends from ____ to ____

• what does it conduct

• Tonsils present

Posterior nasal apertures → soft palate

• Conducts ONLY air

• Pharyngeal and tubal tonsils

  

The oropharynx extends from ____ to ____

• what does it conduct

• Tonsils present

Superior border of soft palat to superior border of epiglottis

• BOTH air, food/liquid

• Palatine tonsils + Lingual tonsils

The Laryngopharynx extends from ____ to ____

• what does it conduct

• Tonsils present

Superior border of epiglottis and pharyngeoepiglottic folds to inferiorborder of circoid cartilage

• Both air, food/liquid

• None

What is the pathway of air through the pharynx

Nasal cavity → Nasopharynx → Oropharynx → Laryngopharynx → Larynx → Lower airway

What is the pathway of food/liquid through the pharynx

Oral cavity → oropharynx → laryngopharynx → oesophagus

What is the role of the epiglottic cartilage in the larynx

Leaf-shaped cartilage above the inlet; moves with the tongue base and hyoid-laryngeal complex to help close the entrance

What is the role of the thyroid cartilage in the larynx

Largest laryngeal cartilage; protects the vocal folds and provides attachment for laryngeal and ligaments

What is the role of the circoid cartilage in the larynx

Complete ring of cartilage inferior to the thyroid cartilage; supports the larynx and connects it to the trachea

What is the role of the arytenoid cartilage in the larynx

Paired cartilage that move and postion the vocal folds allowing them to open or close

What is the role of the laryngeal cartilage in the larynx

Suprior opening into the larynx; remains open for breathing and closes / protects the airway during swalloing

What is the role of the vestibular folds / false vocal cords in the larynx

False vocal folds located superior to the true vocal folds; help protect and close the airway during swallowing

What is the role of the true vocal folds in the larynx

Vibrate to produce soundl abduct for breathing and adduct for phonation and airway protection

What is the role of the rima glottidis in the larynx

Opening between the true vocal folds; widens during breathing and narrows/closes phonation and airway protection

How does vocal-fold position differ during quiet breathing and during phonation?

During quiet breathing, the true vocal fold are abducted (moved laterally), opening the rima glottidis so air can pass. During phonation, they adduct (move medially), narrowing the rima glottidis so airflow causes the vocal folds to vibrate and produce sound 

How does elevation of the hyoid–laryngeal complex, together with the epiglottis, protect the airway during swallowing?

This movement, together with movement of the tongue base, helps the epiglottis fold posteriorly over the laryngeal inlet, directing the bolus away from the airway and toward the oesophagus.

What broad roles do the suprahyoid and infrahyoid groups play in moving and stabilising the hyoid and larynx?

The suprahyoid muscles elevate and pull the hyoid–laryngeal complex anteriorly during swallowing. The infrahyoid muscles stabilize the hyoid and help return the hyoid and larynx inferiorly toward their resting position after swallowing.

Posterior circoarytenoid main action and vagal branch supplying it

Main action: main abductor of the vocal folds

Vagal branch: recurrent laryngeal nerve (Vagus nerve CN 10)

Circothyroid main action and vagal branch supplying it

Main action: increases tension of the vocal folds

Vagal branch: external laryngeal nerve

What are the two functional muscles of the tongue and their main function

Intrinsic muscles: mainly change the tongue shape

Extrinsic muscles: change tongue position

What cranial nerve is responsible for GENERAL SENSATION for the anterior 2/3 of tongue

CN V3

What cranial nerve is responsible for TASTE for the anterior 2/3 of tongue

CN VII (Chorda tympani)

What cranial nerve is responsible for GENERAL SENSATION and TATSE for the posterior 1/3 of tongue

CN IX

What cranial nerve is responsible for tongue movement

CN XII

Label