B18 - Pharynx, esophagus, blood supply and innervation

Question 1

Pharynx

Structures to mention

Answer 1

Cavum pharyngis

• Pars nasalis pharyngis [=nasopharynx] (Extends from the choanae to the ostium intrapharygeum)
• Fornix pharyngis (Most dorsal part of the cavity)
• Ostium tubae auditivae (Pharyngeal opening of the auditory tube)
• Recessus pharyngeus (Un) (Niche at the caudodorsal angle of the nasopharynx)
• Diverticulum pharyngeum (su) (Median caudal blind sac formed by the mucous membrane of the nasopharynx dorsal to the esophagus)
• Ostium intrapharyngeum (Passage between pars nsalis and pars laryngea pharyngis, formed by the free border of the soft palate and the right and left arcus palatopharyngeus)
• Palatum molle
• Arcus palatoglossus (Ridge or fold of mucosa extending from the soft palate to the tongue at the boundary between mouth and pharynx)
• Arcus palatopharyngeus (Mucosal fold extending from the free border of the soft palate around the ostium intrapharyngeum)
• Isthmus faucium (Orifice between cavum oris and pars oralis pharyngis, bound by arcus palatoglossi, soft palate and tongue)
• Pars oralis pharyngis [=oropharynx] (Extends from the arcus palatoglossi to the base of the epiglottis)
• Tonsilla palatina (ø sus) (The tonsil related to the lateral attachment of the soft palate between arcus palatoglossus and alatopharyngeus)
• Plica semilunaris (ca) (Fold of mucosa from the ventral surface of the lateral part of the soft palate, forms the medial wall of the fossa tonsillaris)
• Fossa tonsillaris (ca) (Depression containing the palatine tonsil)
• Vallecula epiglottica (Depression between the tongue and the epiglottis and between plica glossoepiglottica mediana and lateralis)
• Plica glossoepiglottica mediana (Median fold from the tongue → epiglottis)
• Plica glossoepiglottica lateralis (Lateral fold from the tongue → epiglottis)
• Pars laryngea pharyngis [=laryngopharynx] (Part of the pharynx ventral to the ostium intrapharyngeum, extends from base of epiglottis → esophagus)
• Recessus piriformis (Channel between epiglottis, plica aryepiglottica and arytenoid cartilage medially, and membrana thyrohyoidea and thyroid cartilage laterally)
• Limen pharyngooesophageum (car) (Interior boundary between pharynx and esophagus)

Tunica muscularis pharyngis

• Raphe pharyngis (Median dorsal line of termination of the pharyngeal constrictors)
• Mm. constrictores pharyngis rostr. (Muscle of soft palate)
  
  • M. pterygopharyngeus
  • M. stylopharyngeus rostralis (Ru)
  • M. stylopharyngeus caudalis
• M. constrictor pharyngis medius
  
  • M. hyopharyngeus
• Mm. constrictores pharyngis caud.
  
  • M. thyreopharyngeus
  • M. cricopharyngeus
• Musculi palati et faucium
  
  • M. levator veli palatini
  • M. tensor veli palatini
  • M. palatinus
  • M. palatopharyngeus

Question 2

Pharynx

Give the interspecies differences in cavum pharyngis

Answer 2

• Recessus pharyngeus (un) (Cavum pharyngis)
• Diverticulum pharyngeum (sus) (Cavum pharyngis)
• Tonsilla palatina (ø sus)
• Plica semilunaris (ca) (Oropharynx, covers the tonsils)
• Fossa tonsillaris (ca) (Oropharynx)
• Limen pharyngooesophageum (ca) (Laryngopharynx)
• M. stylopharyngeus rostralis (ru)
• Un: laryngopharynx extends caudoventrally

Question 3

Pharynx

Give the division of the pharynx

Answer 3

• Nasopharynx
  
  • ​Dorsal part
  • May be considered as a part of the oral cavity
• Oropharynx
  
  • ​Most rostal
  • Pars digestoria
• Laryngopharynx
  
  • ​Caudal part
  • Extends from base of epiglottis → esophagus

Question 4

Pharynx

What is the pharynx bordering?

Answer 4

• Dorsal:
  
  • Base of skull
  • Tirst couple of cervical vertebrae
• Ventral:
  
  • Larynx
  • Radix linguae
• Lateral:
  
  • M. pterygoideus
  • Mandible
  • Hyoid apparatus, dorsal part
• Epiglottis:
  
  • Guarding the entrance of the laryx

Question 5

Pharynx

Give the:

1. Roof
2. Floor
3. Walls

Answer 5

• Roof:
  
  • Vomer
  • Body of sphenoid
  • Fornix
• Floor:
  
  • Radix linguae
• Walls:
  
  • Mucous membrane → fascia → pharyngeal muscles → fascia

Question 6

Pharynx

List the openings into the pharyngeal cavity

Answer 6

The pharyngeal cavity has 7 openings

• Choanae → nasal cavity
  
  • Paired
• Ostium pharyngeum tubae auditivae → tuba auditiva of middle ear
  
  • Paired
• Isthmus faucium → oral cavity
  
  • ​Oral cavity → oropharynx
• Aditus laryngis → larynx
  
  • ​Caudoventrally
  • Closed by epiglottis during swallowing
• Esophagus entrance → auditus esophageus
  
  • ​Caudal end of laryngopharynx

Question 7

Pharynx

List the ostium intrapharyngeum

Answer 7

Openings between oropharynx → propper oral cavity

• Soft palate
• Arcus palatoglossus
• Arcus palatopharyngeus
• Linea pharyngeo-esophageum

Question 8

Pharynx

Give the lymphatic organs of the pharynx

Answer 8

• Tonsilla palatina (ø sus) (Lateral wall of oropharynx, ventral aspect of soft palate)
• Tonsilla lingualis (In mucosa of radix linguae)
• Tonsilla epiglottica (ø eq) (Base of epiglottis)
• Tonsilla pharyngea (Root of nasopharynx)
• Tonsilla tubaria lateralis (Wall of pharyngeal opening to tuba auditiva)
• Tonsila veli palatini (Ventral of soft palate)

Question 9

Pharynx

Give the muscles

Answer 9

• Rostral:
  
  • M. palatopharyngeus → M. pterygopharyngeus (constrictors)
• Middle:
  
  • M. stylopharyngeus (dialator)
  • M. hyopharyngeus (constrictor)
• Caudal:
  
  • M. thyropharyngeus (constrictor)
  • M. cricopharyngeus (constrictor)
• Muscles of the palate and fauces:
  
  • M. levator veli palatini
    
    • ​Origin: pars tympanica ossis temporalis
  • M. tensor veli palatini
    
    • ​Origin: processus muscularis
    • Insertion: aponeurosis palatini
  • M. palatinus
    
    • ​Origin: lamina horizontalis ossis palatini
    • Insertion: with palatopharyngeus
    • Action: shortens the palate

Question 10

Esophageus

Give the division of the esophageus

Answer 10

• Pars cervicalis (Pharynx → 1^st rib)
• Pars thoracica (1^st rib → diaphragm)
• Pars abdominalis (Diaphragm → stomach)
• It begins dorsal to cart. cricoidea of the larynx and follows the trachea down the neck
• Esophageus passes throug hiatus esophageus in diaphragm

Question 11

Esophageus

Give the related structures

Answer 11

• Cervical part:
  
  • ​A. carotis communis
  • V. jugularis interna
  • Tracheal duct
  • Cervical lymph nodes
  • Tr. vagosympatheticus
  • N. laryngeus recurrens
  • Thymus (young animals)
• Thoracic part:
  
  • _​_Caudal to dorsal mediastinum
  • Dorsal to bifucation trachealis
  • Crosses right side of arcus aorta
  • Lies between lungs ventral to arcus aorta
  • Accompinied by n. vagus:
    
    • ​R. dorsalis
    • R. ventralis
  • Passes through hiatus esophageus of diaphragm

Question 12

Esophagus

Muscles of esophagus

Answer 12

• Striated muscles, except a caudal segment of smooth muscle sin fe, su, eq
• M. esophageus longitudinalis dorsalis (eq, ru)
• M. esophageus longitudinalis lateralis
• M. esophageus longitudinalis ventralis
• M. bronchoesophageus
• M. pleuroesophageus
• Tendo cricoesophageus: attaches the esophageal musculature to the cricoid and arythenoid cartilages

Question 13

Blood supply

Answer 13

Pharynx:

• A. thyroidea caudalis
• A. thyroidea cranialis
  
  • ​R. pharyngeus (→ pharyngeal wall in the region of the caudal constrictors of the pahrynx)
  • R. cricoarythnoideus
  • R. laryngeus caudalis
• A. laryngea cranialis (ru, sus: ex a. carotis communis, eq: ex a. thyroidea cranialis, car: ex a. carotis externa)
  
  • R. pharyngeus → r. laryngeus
• A. pharyngea ascendens (ru: ex a. carotis communis, eq: ex a. laryngea cranialis, car: ex a. carotis externa, sus: ex a. lingualis)
  
  • ​Rr. palatini (ø ru)
  • Rr. tonsillaris (bo)
• V. thyroidea media (ex v. jugularis interna?)
• V. thryoidea cranialis (ex v. jugularis interna?, eq: ex v. maxillaris)
  
  • R. laryngeus cranialis
  • R. laryngeus caudalis
    
    • ​Arcus laryngeus caudalis (ca)
  • V. laryngeus cranialis? (bo)
  • V. pharyngeus ascendens (eq) (ex a. laryngea cranialis)

Esophagus, pars cervicalis:

• A. carotis communis → rr. esophagei
• V. jugularis externa

Esophagus, pars thoracica:

• A. bronchoesophagea
• V. esophagea → v. azygous
• Car: V. esophagea → v. bronchoesophagea → v. azygous

Question 14

Innervation

Answer 14

Pharynx:

• Parasympathetic:
  
  • N. vagus
    
    • ​Rr. pharyngei
      
      • ​Rr. dorsalis
      • Rr. ventralis
    • N. laryngeus cranialis (from ggl. distales)
      
      • → for. thyroideum
    • N. laryngeus recurrens
    • N. laryngeus caudalis
• Sympathetic:
  
  • N. sympatheticus

Esophageus:

• Vagosympathetic trunk
  
  • ​N. sympatheticus (sympathetic)
  • N. vagus (parsympathetic)
    
    • R. laryngeus recrurrens
• Internal ggl. of plexus myentericus in tunica muscularis