Laryngopharynx Question And Answers

Pharynx Question And Answers

Question 1. Write a short note on the pharynx.


Pharynx Median Section Of Pharynx Is Nasopharynx, Oropharynx, Laryngopharynx

  • It is a funnel-shaped muscular tissue extending from the base of skull to esophagus
  • It is a common channel for both food and air.

Pharynx Dimension And Location

  • It measures approximately 12–14 cm in length and is 1.5–3.5 cm in width
  • It is located behind the cavity of the nose, mouth, and larynx.

Pharynx Boundaries And Relation

  • Superiorly: Base of the skull, including posterior part of sphenoid and basilar part of the occipital bone
  • Inferiorly: Continuous with esophagus at the level of C6 vertebra
  • Anteriorly: Nasal cavity, mouth, and larynx
  • Posteriorly: Prevertebral fascia
  • Laterally: Neurovascular bundle of neck and styloid apparatus

Pharynx Parts: Divided into three parts

  1. Nasopharynx: Lying behind the nose
  2. Oropharynx: Behind oral cavity
  3. Laryngopharynx: Behind the larynx.

1. Nasopharynx

  • It is situated behind nose and extends from the base of skull to soft palate
  • It communicates anteriorly through nose and posteriorly through choana and inferiorly with the oropharynx
  • Lined by ciliated columnar epithelium
  • It acts as a passage for air
  • The main features seen in this part include:
    • Nasopharyngeal tonsil/adenoids
    • Opening of Eustachian tube
    • Pharyngeal recess/fossa of Rosenmüller
  • Supplied by pharyngeal branches of the pterygopalatine ganglion.

2. Oropharynx

  • Situated behind oral cavity and extends from soft palate to upper border of the epiglottis
  • It communicates anteriorly with oral cavity through the oropharyngeal isthmus, above with nasopharynx through the nasopharyngeal isthmus inferiorly with the laryngopharynx
  • It is lined by stratified squamous non-keratinized epithelium
  • It acts as a common passage for food and air
  • The main features seen in this part include:
    • Palatine tonsil
    • Palatoglossal arch
    • Palatopharyngeal arch
    • Lingual tonsil
    • The free end of the epiglottis
    • Valleculae
    • Glossoepiglottic folds.

3. Laryngopharynx

  • Situated behind larynx and extends from the upper border of the epiglottis to lower border of the cricoid cartilage
  • It communicates anteriorly with the laryngeal cavity through the laryngeal inlet and inferiorly with the esophagus at the pharyngoesophageal junction
  • It is lined by stratified squamous non-keratinized epithelium
  • It mainly acts as a passage for food
  • The main features seen in this part include:
    • Laryngeal inlet
    • Piriform fossa.
    • Supplied by 9 and 10th cranial nerves.

Blood Supply Of Pharynx

  • Arterial
    • Ascending pharyngeal artery
    • Ascending palatine artery
    • Ascending tonsilar artery
    • Greater palatine artery
    • Lingual artery
  • Venous drainage: Into pharyngeal venous plexus and ultimately to internal jugular vein.

Pharynx Lymphatic Drainage: Drain into upper and lower deep cervical nodes.

Pharynx Nerve Supply

  • Sensory
    • Nasophaynx: Pharyngeal branch of the pterygopalatine ganglion
    • Oropharynx: Glossopharyngeal nerve
    • Laryngopharynx: Internal laryngeal nerve
  • Motor: All muscles are supplied by the cranial root of the accessory nerve except stylopharyngeus which is supplied by the glossopharyngeal nerve.

Pharynx Applied

  • Pharyngeal tonsil or adenoids usually regress by puberty.
  • Enlargement of adenoids can lead to obstruction of the posterior nasal aperture and can interfere with respiration and speech.
  • Pharyngitis refers to the inflammation of the pharynx and can be caused as a result of viral, bacterial, or fungal infections.
  • In faucial diphtheria, a grayish-white membrane forms over the tonsil which later extends to the soft palate and posterior pharyngeal wall and causes bleeding when removed.
  • Retropharyngeal space is the space between buccopharyngeal fascia covering the pharyngeal constrictor muscles and prevertebral fascia. The suppuration of retropharyngeal lymph nodes can result in retropharyngeal abscess.

Laryngopharynx Route Of AIr Through Human Lungs

Question 2. Write a short note on the palatine tonsil.

Palatine tonsil

Pharynx Relations Of Tonsil

Pharynx Sources Of Arterial Supply Of Palkatine Tonsil

  • It is an almond-shaped mass of lymphoid tissue.
  • It is situated in the tonsillar fossa of the lateral wall of the oropharynx between anterior and posterior pillars.
  • The anterior pillar is formed by the palatoglossal arch and the posterior pillar is formed by the palatopharyngeal arch.

Palatine Tonsil Boundaries And Relation

  • Anteriorly: Anterior pillar with palatoglossal muscle
  • Posteriorly: Posterior pillar with palatopharyngeus muscle
  • Apex: Soft palate
  • Base: Dorsal surface of posterior 1/3rd of tongue
  • Laterally (tonsillar bed):
    • Pharyngobasilar fascia
    • Superior constrictor muscle
    • Buccopharyngeal fascia
    • Styloglossus
    • Glossopharyngeal nerve

Palatine Tonsil Features: Consist of 2 surfaces, 2 borders, and 2 poles

  • Medial surface: Free and bulge to the oropharynx and lined by non-keratinized stratified squamous epithelium
  • Tonsillar crypts are present and the largest and deepest crypt called crypto magna is present
  • Lateral surface: Covered by fibrous tissue and forms a capsule of tonsil and is loosely attached to the pharyngeal wall and anteroinferior it is firmly adhered to side of the tongue
  • Anterior border: Related to palatoglossal arch and muscle
  • Posterior border: Related to palatopharyngeal arch and muscle
  • Upper pole is related to the soft palate and lower pole to the tongue.

Blood Supply Of Tonsil

  • Arterial supply: Mainly by a tonsillar branch of the facial artery
    • Dorsal lingual branch of lingual artery
    • Ascending palatine artery
    • Ascending pharyngeal artery
    • Descending palatine artery
    • Greater palatine artery
  • Venous drainage: Drains into peritonsillar vein which in turn drain into pharyngeal venous plexus.

Palatine Tonsil Lymphatic Drainage: Drains into upper deep cervical nodes mainly jugulodigastric nodes.

Palatine Tonsil Nerve Supply: Supplied by glossopharyngeal nerve and branches from sphenopalatine ganglion.

Palatine Tonsil Applied

  • In children, tonsils are the frequent sites of infection.
  • Acute infections of the tonsil can lead to acute tonsillitis. It can be membranous or follicular or parenchymatous.
  • Spread of infection from tonsils to surrounding areas can lead to peritonsillar abscess.
  • Tonsillectomy refers to the removal of tonsils and is indicated when the tonsils interfere with speech, swallowing, or respiration and cause recurrent attacks.

Question 3. Write a short note on the constrictor muscles of the pharynx.

Constrictor muscles of the pharynx

Pharynx Simplified Depiction Of Constrictor Muscles Of Pharynx

Pharynx Flower-pot Arrangement Of The Constrictor Muscles In The Wall Of The Pharynx

  1. Simplified depiction of constrictor muscles of the pharynx
    1. Ascending pharyngeal artery;
    2. Ascending palatine artery;
    3. Pterygomandibular raphe;
    4. Internal laryngeal nerve;
    5. Superior laryngeal artery);
  2. Flower­pot arrangement of the constrictor muscles in the wall of the pharynx (Structures passing through the gaps in the pharyngeal wall)
  • These muscles form the bulk of the muscular coat of the pharyngeal wall.
  • The origin of the constrictor are situated anteriorly in relation to the posterior openings of nose, mouth, and larynx.
  • From there the fibers pass backward to lateral walls in a fan-shaped manner and get inserted to the median raphe of the pharynx.
  • The muscles are arranged like a flower pot without a base placed one above the other and open in front for communicating with nasal, oral, and laryngeal cavities.
  • The fibers of inferior constrictor overlap the middle constrictor and which in turn overlaps superior constrictor.

Detail Of Muscles

  • Superior Constrictor
    • Superior Constrictor Origin:
      • Pterygoid hamulus
      • Pterygomandibular raphe
      • Medial surface of mandible at upper end of the mylohyoid line
      • Side of the posterior part of tongue
    • Superior Constrictor Insertion: Pharyngeal tubercle
      • Median raphe
    • Superior Constrictor Nerve supply: Pharyngeal plexus through pharyngeal branch of vagus
    • Superior Constrictor Action: Helps in deglutition
  • Middle Constrictor
    • Middle Constrictor Origin:
      • Lower part of the stylohyoid ligament
      • Lesser cornua and greatercornua of hyoid bone
    • Middle Constrictor Insertion: Median raphe
    • Middle Constrictor Nerve supply: Pharyngeal plexus through pharyngeal branch of vagus
    • Middle Constrictor Action: Helps in deglutition
  • Inferior Constrictor: Consists of two parts
    1. Thyropharyngeus
      • Inferior Constrictor Origin:
        • Oblique line on lamina of thyroid cartilage
        • Tendinous band attached to inferior tubercle of thyroid cartilage
      • Inferior Constrictor Insertion: Median raphe
      • Inferior Constrictor Nerve supply:
        • External laryngeal nerve
        • Pharyngeal plexus
  • Cricopharyngeus
    • Cricopharyngeus Origin: Cricoid cartilage
    • Cricopharyngeus Insertion: Median raphe
    • Cricopharyngeus Nerve supply:
      • Recurrent laryngeal nerve
      • Pharyngeal plexus
    • Cricopharyngeus Action: Helps in deglutition

Structures Passing through Space between Constrictors

  • Between base of skull and superior constrictor: Auditory tube
    • Levator veli palatini
    • Ascending palatine artery
    • Palatine branch of ascending pharyngeal artery
  • Between superior and middle constrictor: Stylopharyngeus muscle
    • Glossopharyngeal nerve
  • Between middle and inferior constrictor: Internal laryngeal nerve
    • Superior laryngeal vessel
  • Between inferior constrictor and esophagus: Recurrent laryngeal nerve
    • Inferior laryngeal vessels

Question 4. Write a short note on Killian’s dehiscence.

Killian’s dehiscence

  • The gap between the thyropharyngeus and cricopharyngeus muscle is called Killian’s dehiscence or pharyngeal dimple.
  • The mucosa and submucosa of the pharynx can bulge through this area to form a pharyngeal pouch.

Question 1. The pharyngeal wall consists of all the following except:

  1. Mucous membrane
  2. Pharyngobasilar fascia
  3. Buccopharyngeal fascia
  4. Prevertebral fascia

Answer: 4. Prevertebral fascia

Question 2. All of the following are features of nasopharynx except:

  1. Pharyngeal tonsil
  2. Tubal tonsil
  3. Pharyngeal recess
  4. Piriform recess

Answer: 4. Piriform recess

Question 3. The Pas savant’s ridge is formed by:

  1. Salpingopharyngeus
  2. Stylopharyngeus
  3. Palatopharyngeus
  4. Thropharyngeus

Answer: 3. Palatopharyngeus

Question 4. Motor nerve supply of pharyngeal muscles is derived from:

  1. Vago-accessory complex
  2. Glossopharyngeal nerve
  3. External laryngeal nerve
  4. All of the above

Answer: 4. All of the above

Question 5. Inferior constrictor of pharynx is supplied by all of the following nerves except:

  1. Pharyngeal plexus
  2. Glossopharyngeal nerve
  3. External laryngeal nerve
  4. Recurrent laryngeal nerve

Answer: 2. Glossopharyngeal nerve

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