C6 - Pharynx, oesophagus, 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

• Divisions in the rostral portion of cavum pharyngis
• Divided by palatum molle into:
  
  • Nasopharynx
  • Oropharynx
  • Laryngopharynx

Question 4

Pharynx

Division of pharynx: nasopharynx

Answer 4

• ​Dorsal to palatum molle
• May be considered as a part of the oral cavity
• Extends from choanae → intrapharyngeal opening
• Roof (fornix pharyngis):
  
  • Dorsal part
  • Composed of:
    
    • Septum pharyngis (su, ru)
    • Tonsilla pharyngea
      
      • ​On the caudodorsal wall
      • Su, ru: in septum pharyngis
    • Ostium pharyngeum tubae auditivae
    • Torus tubarius
      
      • ​Swelling caudodorsal to ostium tubae
      • Caused by the median lamina of the cartilage of tuba auditiva
    • Torus levatorius
      
      • ​Low ridge
      • Runs from ostium pharyngeum tubae → palatum molle
    • Tonsilla tubaria
      
      • ​Su, ru: at the ostium pharyngeum
    • Recessus pharyngeus​ (un)
      
      • ​Niche at the caudodorsal angel of nasopharynx

Question 5

Pharynx

Division of pharynx: oropharynx

Answer 5

• ​Most rostal
• Part of the digestive tract
• Extends from arcus palatoglossus → base of epiglottis
• Roof: Formed by palatum molle
• Floor: Formed by radix linguae
• Lateral walls:
  
  • Arcus palatoglossus
  • Arcus palatopharyngeus
  • Fossa tonsillaris (car)
    
    • Tonsilla palatina
  • Plica semilunaris (car)
    
    • Fold fo mucosa from palatum molle
    • Forms the medial wall of fossa tonsillaris
  • Tonsilla veli palatini (su, eq)
  • Plica glossoepiglottica meiana
    
    • ​Median flod from tongue to epiglottis
  • Plica glossoepiglottica lateralis
    
    • ​Lateral folds from tongue to epiglottis
  • Vallecula epiglottica
    
    • ​Depression between the tongue and epiglottis
    • Depression between plica glossoepiglottica mediana et lateralis
• Isthmus faucium
  
  • ​Orifice between oral cavity and oropharynx

Question 6

Pharynx

Division of pharynx: laryngopharynx

Answer 6

• ​Caudal part
• Ventral to ostium intrapharyngeum
• Extends from base of epiglottis → esophagus
• Food and liquid pass through the recess into esophagus
• Esophagus is an direct continuation of laryngopharynx

​

• Recessus piriformis
  
  • ​On each side of epiglottis
  • Channel between:
    
    • Epiglottis
    • Plica aryepiglottica
    • Cartilao arythenoidea (medially)
    • Membrana thyroidea
    • Cartilago thyroidea (laterally)
• Vestibulum esophagei (pars esophagea)
  
  • Part of laryngopharynx between cartilago aryhenoidea and beginning of esophagus
• Limen phaygoesophageum (car)
  
  • Annular fold of mucous membrane
  • Interior boundary between pharynx and esophagus

Question 7

Pharynx

What is the pharynx bordering?

Answer 7

• 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 8

Pharynx

Give the:

1. Roof
2. Floor
3. Walls

Answer 8

Roof:

• Related to:
  
  • Vomer
  • Corpus shenoidalis
  • Basis cranii
• Car: extends to C2
• Eq:
  
  • 19-20 cm
  • Rostral third of roof attached to basis cranii
  • Caudal two-thirds reladed to the guttural pouches
• Ru: short, does not extend caudayy beyond the base of the skull
• Su: extends to the level of the axis

Lateral walls:

• Related to:
  
  • Sylohyoideus
  • M. pterygoideus
  • Eq: guttural pouches
• Mucous membrane → fascia → pharyngeal muscles → fascia

Floor:

• Extends:
  
  • From radix linguae
  • Over and around aditus laryngis (laryngeal entrance)
  • To the level of cartilage cricoidea

Question 9

Pharynx

List the openings into the pharyngeal cavity

Answer 9

The pharyngeal cavity has 7 openings

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

Question 10

Pharynx

List the ostium intrapharyngeum

Answer 10

• Located above aditus laryngis (entrance of larynx)
• Surrounded by:
  
  • The free border of palatum molle
  • Palatopharyngeal arches
• Through the ostium, nasopharynx communicates with laryngopharynx
• Openings between oropharynx → propper oral cavity
• Soft palate
• Arcus palatoglossus
• Arcus palatopharyngeus
• Linea pharyngeo-esophageum

Question 11

Pharynx

List the structures of the pharyngeal wall

Answer 11

1. ​​Mucous membrane
2. Pharyngeal muscles
3. Fascia pharyngis
4. Raphe pharyngis
   
   • ​Median, dorsal line
   • Termination of constrictor muscles

Question 12

Pharynx

Give the lymphatic organs of the pharynx

Answer 12

• 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 13

Pharynx

Give the muscles

Answer 13

Rostral pharyngeal constrictor muscles:

• M. pterygopharyngeus
  
  • ​Origin: os pterygoideum, aponeurosis palatina (ø eq)
  • Insertion: raphe pharyngis
  • Action: sphincter
• M. palatopharyngeus
  
  • ​Origin: os palatinum et pterygoideum
  • Insertion: raphe pharyngis
  • Action: sphincter
• M. stylopharyngeus rostralis​
  
  • ​Origin: distal half of stylohyoideum
  • Insertion: raphe pharyngis (occurs in ru??)
  • Action: sphincter
• M. stylopharyngeus caudalis​
  
  • ​Origin: proximal half of stylohyoideum
  • Insertion: wall of pharynx
  • Action: dilator

Middle pharyngeal constrictor muscles:

• M. ceratopharyngeus
  
  • ​Origin: ceratohyoideum
  • Insertion: raphe pharyngis
  • Action: sphincter
• M. chndropharyngeus​
  
  • ​Origin: tyrohyoideum
  • Insertion: raphe pharyngis
  • Action: sphincter

Caudal pharyngeal constrictor muscles:

• M. thyropharyngeus
  
  • ​Origin: linea obligua of cartilago thyroidea
  • Insertion: raphe pharyngis
  • Action: sphincter
• M. cricopharyngeus​
  
  • ​Origin: cartilago cricoidea
  • Insertion: raphe pharyngis
  • Action: sphincter

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 14

Esophageus

Give the division of the esophageus

Answer 14

• 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 15

Esophageus

Give the related structures

Answer 15

• 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 16

Esophagus

Tendo cricoesophageus

Answer 16

• Attaches the esophageal musculature to the cricoid and arythenoid cartilage

Question 17

Esophagus

Muscles of esophagus

Answer 17

• Striated muscles, except a caudal segment of smooth muscle in fe, su, eq

1. M. esophageus longitudinalis dorsalis (eq, ru)
2. M. esophageus longitudinalis lateralis
3. M. esophageus longitudinalis ventralis
4. M. bronchoesophageus
5. M. pleuroesophageus

• Tendo cricoesophageus: attaches the esophageal musculature to the cricoid and arythenoid cartilages

Question 18

Esophagus

Constrictons of esophagus

Answer 18

• Isthmus oesophagei (cervical constriction)
  
  • ​Above larynx
• Isthmus thoracalis (thoracic constriction)
  
  • ​At the level of C7
  • Passes dorsal to the trachea
  • Esophagus moves from the left side of trachea, above the trachea
• Istmus diaphragmatica (abdominal constriction)
  
  • ​The hiatus esophageus - where it passes through diaphragm in the posterior mediastinum

Question 19

Blood supply

Answer 19

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 20

Innervation

Answer 20

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