Pharynx And Larynx

Question 1

Glossopharyngeal nerve (CN9)

Answer 1

Motor to the stylopharyngeus

Sensory to the pharyngeal plexus

• auditory tube
• tonsils
• uvula
• pharynx
• posterior 1/3 of tongue taste and sensation

Question 2

Vagus nerve (CN10)

Answer 2

only as it pertains to the pharynx and larynx

Motor to the

• soft palate
• pharyngeal plexus
• laryngeal muscles

Sensory to the

• epiglottis
• laryngopharynx and larynx

V3 tenses the soft palate

Question 3

Hypoglossal nerve (CN 12)

Answer 3

Motor to all intrinsic and extrinsic muscles of the tongue except palatoglossus (CN 10)

Includes

• styloglossus
• genioglossus
• hyoglossus

Question 4

Deep cervical fascia

Answer 4

Deep to the investing fascia and includes the pretracheal muscular fascia and the pretracheal visceral fascia

• originates on Posterior hyoid bone

Question 5

Thyroid gland

Answer 5

Thyroid: sits right under the thyroid cartilage (Adams apple)
- prime metabolic endocrine organ and contains right/left lobes, pyramid lobe (most superior portion) and an isthmus (most inferior portion)

Blood supply contain 3 major branches
- superior, inferior and middle thyroid artery’s/veins

• DOES NOT COMMUNICATE WITH PARATHYROID GLANDS*
• communicates with pituitary gland

Question 6

Parathyroid glands

Answer 6

Posterior of the thyroid cartilage and the thyroid

• NOT DEVELOPED WITH THYROID*

Primary endocrine gland of calcium homeostasis

Takes signals from blood calcium levels, NOT pituitary gland

Question 7

Are thyroid and parathyroid glands innervated by nerves

Answer 7

No, they are modulated based on vasomotor of their blood supply via cervical ganglia
- function based on what hormones and cervical ganglia tell them to do

Question 8

What happens if you lose sympathetic or parasympathetic innervation to the thyroid/ parathyroid glands?

Answer 8

Nothing really. Primarily modulated by blood supply

Question 9

Lingual thyroid

Answer 9

Abnormal development of the thyroid as it results from descent of the thyroid.

Question 10

Pharyngeal divisions (most superior to inferior)

Answer 10

Nasopharynx

Oropharynx
- starts at soft palate

Laryngopharynx
- starts at epiglottis

Question 11

Tonsils

Answer 11

Very rich in lymphoid connective tissues

3 types:

• Palatine
• Pharyngeal (adenoid)
• Lingual

Question 12

Paraphayngeal spaces

Answer 12

Retropharyngeal

Anterior and posterior lateropharyngeal

Sites of potential infection spread via tonsillitis

Question 13

Pharyngeal constrictor muscles

Answer 13

Superior constrictor (4 segments)

Middle constrictor (2 segments)
- off hyoid bone 

Inferior constrictor (2 segments)
- off laryngeal cartilage 

Constrict starting from the superior portion and move downwards to push food down into the stomach

Question 14

Levator and tensor veli palatini

Answer 14

Elevate and tense the soft palate respectively

- also have CN 10 and V3 innervation respectively

Question 15

Deglutition

Answer 15

Swallowing

Coordinated progression of movements and takes innervation from the following:

• V3: muscles of mastication and tensor veli palatini and sensation to the anterior 2/3 of tongue via maxillary nerve
• Facial nerve (CN 7): buccinator, levator veli palatini and suprahyoid muscles and taste to the anterior 2/3 of the tongue
• vagus nerve (CN 10): palate muscles and pharyngeal constrictors as well as sensation to the pharynx/larynx
• glossalpharyngeal nerve (CN 9): stylopharyngeus and taste/sensation to the posterior 1/3 of the tongue
• hypoglossal nerve (CN 12): muscles of the tongue
• C1-C3 rami: infrahyoid muscles
• salivary glands also play a role and require 7 and 9 CNs*

Question 16

First step of deglutition

Answer 16

Mastication via muscles of mastication and pushing the bolus to the oropharynx via the buccinator and the tongue

Question 17

Second step of deglutition

Answer 17

Muscles of the soft palate lift the pharynx up and act as a flap valve to force the bolus to move down the oropharynx and not pass up into the nasopharynx.

Question 18

Third step of deglutition

Answer 18

Pharyngeal constrictors function to squeeze the bolus downward into laryngopharynx, bowling over the epiglottis to prevent food from entering the wind pipe

mammals are special because of the soft palate, only species to have it

Question 19

Innervation to larynx and thyroid

Answer 19

Vagus nerve via superior and recurrent laryngeal nerves

Question 20

Larynx broad parts and its innervation

Answer 20

From superior to inferior

Quadrangular membrane

Ventricle of the larynx
- false vocal folds (end of innervation via the superior laryngeal

• true vocal folds (beginning of innervation via the recurrent laryngeal

Cricothyroid membrane

Question 21

Joints of the larynx

Answer 21

All are synovial joints

Cricothyroid joint (hinge)

Cricoarytenoid joint (rotate)

Question 22

Laryngeal muscle functions

Answer 22

Cricothyroid: tightens cord

Thyroarytenoid: adducts cords

Lateral cricoarytenoid: adducts cords

Posterior cricoarytenoid: abducts cords

Vocalis: fine tunes cord tension

Question 23

Gag reflex

Answer 23

Uvula is the trigger of the gag reflex (CN 9 sensory w/ CN 10 motor)
- caused by a reflex loop between CN 9 and CN 10

Maxillary nerve via the lesser palatine nerve may also play a small role

Question 24

Auditory (Eustachian) tube

Answer 24

Opened via the Salpingopharyngeus, levator and tensor veli palatini, and the palatopharyngeus Muscles

Function to equalize pressure of the tympanic membrane and prevent yourself from hearing yourself chew too loudly

Innervated by tympanic plexus and gets blood via maxillary artery and ascending pharyngeal artery

Question 25

Roma glottis

Answer 25

Space between the true vocal folds