Difference between revisions of "Pharynx - Anatomy & Physiology"

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<big><center>[[Musculoskeletal System - Anatomy & Physiology|'''BACK TO MUSCULOSKELETAL ANATOMY AND PHYSIOLOGY''']]</center></big>
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==Introduction==
 
==Introduction==
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[[Image:Developing Head.jpg|thumb|right|250px|Developing Head - from [[Oral Cavity Histology resource|Oral Cavity PowerPoint]] ]]
 
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The pharynx is part of both the [[Cardiorespiratory System Overview - Anatomy & Physiology|respiratory]] and [[Alimentary System Overview - Anatomy & Physiology|digestive]] system. Both systems have entrances to the pharynx but they are separated from each other by the [[Soft Palate|soft palate]].
 
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During exercise or during respiratory distress, the mouth can be used as an additional opening of the respiratory system and then the [[Oropharynx - Anatomy & Physiology|oropharynx]] also becomes an air-way.
 
  
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The pharynx can be split into different regions - the [[Oropharynx - Anatomy & Physiology|oropharynx]], [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]] (sometimes referred to as the oesophageal pharynx) and the nasopharynx.
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The pharynx is part of both the [[Cardiorespiratory System - Anatomy & Physiology|respiratory]] and [[Alimentary - Anatomy & Physiology|digestive]] system. Both systems have entrances to the pharynx but they are separated from each other by the [[Soft Palate - Anatomy & Physiology|soft palate]].
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[[Image:Nasopharynx.jpg|thumb|right|250px|Nasopharynx Anatomy - Copyright RVC]]
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During exercise or during respiratory distress, the mouth can be used as an additional opening of the respiratory system and then the [[Oral Cavity - Oropharynx - Anatomy & Physiology|oropharynx]] also becomes an air-way.
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The pharynx can be split into different regions- the [[Oral Cavity - Oropharynx - Anatomy & Physiology|oropharynx]], [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]] (sometimes referred to as the oesophageal pharynx) and the [[Nasopharynx - Anatomy & Physiology|nasopharynx]]
  
 
==Structure and Function==
 
==Structure and Function==
  
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The opening of the [[Larynx - Anatomy & Physiology|larynx]] is on the floor of the pharynx. Caudal and dorsal to the laryngeal opening is the opening into the [[Oesophagus - Anatomy & Physiology|oesophagus]]. In the dorsal region of the nasopharynx, there are paired openings into the auditory (eustachian) tubes. The lining of the middle ear cavity and auditory tube is continuous with that of the nasopharynx. The pharynx is located between the base of the skull and the first two cervical vertebrae dorsally and the [[Larynx - Anatomy & Physiology|larynx]] ventrally. The [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]], pterygoid muscles and [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] are located laterally. Laterally, two pairs of '''palatopharyngeal arches''' are present from the [[Soft Palate|soft palate]] to the [[Oesophagus - Anatomy & Physiology|oesophagus]].
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*Opening of the [[Larynx - Anatomy & Physiology|larynx]] is on the floor of the pharynx
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[[Image:Pharynx Anatomy.jpg|thumb|right|250px|Pharynx Labelled - Copyright C.Clarkson and T.F.Fletcher University of Minnesota]]
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*Caudal and dorsal to the laryngeal opening is the opening into the [[Oesophagus - Anatomy & Physiology|oesophagus]]
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*In the dorsal region of the [[Nasopharynx - Anatomy & Physiology|nasopharynx]] there are paired openings into the Auditory (Eustacian) Tubes
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*The lining of the middle ear cavity and auditory tube is continuous with that of the [[Nasopharynx - Anatomy & Physiology|nasopharynx]]
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*Located between the base of the skull and the first two cervical vertebrae dorsally
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*[[Larynx - Anatomy & Physiology|larynx]] ventrally
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*Mandible, pterygoid muscles and [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] laterally
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*Walls contain striated muscle
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*During [[Deglutition|swallowing]] the [[Soft Palate - Anatomy & Physiology|soft palate]] is raised which divided the pharynx into dorsal and ventral sections
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**Laterally, two pairs of palatopharyngeal arches are present from the [[Soft Palate - Anatomy & Physiology|soft palate]] to the [[Oesophagus - Anatomy & Physiology|oesophagus]]
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**The dorsal compartment is the [[Nasopharynx - Anatomy & Physiology|nasopharynx]]
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**The rostral compartment is the [[Oral Cavity - Oropharynx - Anatomy & Physiology|oropharynx]]
  
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The walls of the pharynx contain striated muscle. During [[Deglutition|swallowing]], the soft palate is raised which divides the pharynx into dorsal and ventral sections. The dorsal compartment is the nasopharynx and the rostral compartment is the [[Oropharynx - Anatomy & Physiology|oropharynx]]. The [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]] is separated from the oropharynx by the [[Larynx - Anatomy & Physiology#Epiglottis|epiglottis]]. [[Tonsils - Anatomy & Physiology|Tonsils]] are present on the lateral walls of the oropharynx and are covered by flaps of mucosa.
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*The laryngeal pharynx is separated from the [[Oral Cavity - Oropharynx - Anatomy & Physiology|oropharynx]] by the [[Epiglottis|epiglottis]]
  
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The pharynx plays an important role in [[Deglutition|deglutition]].
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*Tonsils are present on the lateral walls of the [[Oral Cavity - Oropharynx - Anatomy & Physiology|oropharynx]]  
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[[Image:Soft Palate Separating Pharyngeal Cavities.jpg|thumb|right|250x|Soft palate dividing the oropharynx and the nasopharynx - Copyright RVC]]
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**Covered by flaps of mucosa
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**Partially visible in the open mouth
  
 
==Musculature==
 
==Musculature==
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Pharyngeal muscles arise from '''arch 4''' except for the stylopharyngeous muscle that comes from '''arch 3'''.
 
  
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===Muscles that constrict===
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===Constictors===
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Muscles that constrict the pharynx run dorsally to its roof. Rostral constrictor muscles are the '''hyopharyngeous''', '''pterygopharyngeous''' and the '''palatopharyngeous muscles'''. They originate from the [[Tonsils - Anatomy & Physiology#Pterygoid Bone (os pterygoideum)|pterygoid]] region of the skull and insert on the aponeurosis of the [[Soft Palate|soft palate]] and shorten the pharynx. The middle constrictor muscle is the '''thyopharyngeous muscle'''. It originates from the [[Hyoid Apparatus - Anatomy & Physiology|hyoid bone]]. Caudally is the '''cricopharyngeous muscle''', which originates from the [[Larynx - Anatomy & Physiology#Thyroid Cartilage|thyroid cartilage]] of the larynx.
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*Run dorsally to roof of pharynx
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*Rostral constrictor muscles are the pterygopharyngeous and the palatopharyngeous muscles
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**Originate from the pyerygoid region of the skull and the aponeurosis of the [[Soft Palate - Anatomy & Physiology|soft palate]]
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**Shorten the pharynx
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*Middle constictor muscle is the hyopharyngeous
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**Origniates from the [[Hyoid Apparatus - Anatomy & Physiology|hyoid bone]]
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*Caudal constictor muscles are the thyropharyngeous and the cricopharyngeous muscles
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**Originates from the thyroid cartilage of the [[Larynx - Anatomy & Physiology|larynx]]
  
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===Muscles that dilate===
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===Dilators===
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Muscles that dilate the pharynx enclose it laterally and dorsally. The dilator muscle is the '''stylopharyngeous muscle'''. It originates from the hyoid apparatus and widens the rostral pharynx.
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*Enclose pharynx laterally and dorsally
  
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===Muscles that shorten===
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===Shorteners===
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The '''pterygopharyngeal muscle''' and '''palatopharyngeal muscle''' shorten the pharynx. They enclose the pharynx laterally and dorsally.
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*Enclose pharynx laterally and dorsally
  
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===Muscles that close the Pharyngeal Arch===
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==Vasculature==
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The '''palatopharyngeous muscle''' also closes the pharyngeal arch.
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*
  
 
==Innervation==
 
==Innervation==
  
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The nervous supply comes from the pharyngeal branch of the vagus nerve ([[Cranial Nerves - Anatomy & Physiology|CN X]]) and from the cranial root of the accessory nerve ([[Cranial Nerves - Anatomy & Physiology|CN XI]]). The stylopharyngeous muscle is innervated by the glossopharyngeal nerve ([[Cranial Nerves - Anatomy & Physiology|CN IX]]).
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*
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==Lymphatics==
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*
  
 
==Histology==
 
==Histology==
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[[Image:Pharyngeal Tonsil.jpg|thumb|right|250px|Histology of Pharyngeal Tonsil - from the [[Lymphoid Tissue Histology resource|Lymphoid tissue histology PowerPoint]] ]]
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'''Fibroelastic aponeurosis''' supports the mucosa. The nasopharynx has pseudostratified columnar epithelium. The [[Oropharynx - Anatomy & Physiology|oropharynx]] and the [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]] have stratified squamous epithelium. The oropharynx and the laryngeal pharynx also have [[Salivary Glands - Anatomy & Physiology|salivary glands]] present.
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*
  
 
==Species Differences==
 
==Species Differences==
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[[Image:Pharynx Anatomy.jpg|thumb|right|250px|Palatine Tonsil - Copyright C.Clarkson and T.F.Fletcher University of Minnesota]]
 
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====Canine====
 
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A single duct connects the nasopharynx to the [[Nasal Cavity - Anatomy & Physiology|nasal cavity]]. The [[Tonsils - Anatomy & Physiology|tonsils]] are a compact mass which point away from the lumen of the pharynx.
 
  
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====Equine====
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'''Canine'''
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The auditory tube opens into the [[Ear - Anatomy & Physiology#Equine Guttural Pouch|guttural pouch]] and the tonsils are diffuse and raised slightly. Horses are unable to breathe through the mouth as the free apex of the rostral epiglottis lies dorsal to the soft palate in a normal horse.
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*Single duct connects [[Nasopharynx - Anatomy & Physiology|nasopharynx]] to the nasal cavity
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*Tonsils are a compact mass which point away from the lumen of the pharynx
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'''Equine'''
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*Auditory tube opens into the [[Special Senses - Auditory - Anatomy & Physiology#Equine Gutteral Pouch|gutteral pouch]]
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*Tonsils are diffuse and raised slightly
  
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====Ruminants====
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'''Ruminants'''
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Tonsils are a compact mass which point towards the lumen of the pharynx.
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*Tonsils are a compact mass which point towards the lumen of the pharynx
  
 
==Links==
 
==Links==
  
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Click here for more information on the [[Oropharynx - Anatomy & Physiology|oropharynx]].
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[[Oral Cavity - Oropharynx - Anatomy & Physiology|Oropharynx - Anatomy & Physiology]]
  
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Click here for more information on the [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]].
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[[Nasopharynx - Anatomy & Physiology]]
  
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{{Template:Learning
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[[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]]
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|flashcards = [[Oropharynx Anatomy & Physiology Flashcards]]<br>[[Facial_Muscles_-_Musculoskeletal_-_Flashcards|Facial muscles]]<br>[[Pharynx - Musculoskeletal - Flashcards|Pharynx]]<br>[[Pharynx_-_Musculoskeletal_-_Flashcards#The_Laryngeal_Pharynx_Flashcards|Laryngeal pharynx]]<br>[[Pharynx_-_Musculoskeletal_-_Flashcards#The_Nasal_Pharynx_Flashcards|Nasal pharynx]]
 
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|powerpoints = [[Oral Cavity Histology resource|Histology of the pharynx and larynx]]<br>[[Lymphoid Tissue Histology resource|Histology of lymphoid tissue, including the pharyngeal tonsils]]
 
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|OVAM = [http://www.onlineveterinaryanatomy.net/sites/default/files/original_media/document/asset_9294_Dog%20pharynx%20PDF.pdf Plastinated Dog Pharynx In Situ]
 
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}}
 
  
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{{review}}
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<big><center>[[Musculoskeletal System - Anatomy & Physiology|'''BACK TO MUSCULOSKELETAL ANATOMY AND PHYSIOLOGY''']]</center></big>
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==Webinars==
 
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<rss max="10" highlight="none">https://www.thewebinarvet.com/gastroenterology-and-nutrition/webinars/feed</rss>
 
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[[Category:Respiratory System - Anatomy & Physiology]][[Category:Musculoskeletal System - Anatomy & Physiology]]
 
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[[Category:A&P Done]]
 

Revision as of 17:04, 29 July 2008

BACK TO MUSCULOSKELETAL ANATOMY AND PHYSIOLOGY


Introduction

The pharynx is part of both the respiratory and digestive system. Both systems have entrances to the pharynx but they are separated from each other by the soft palate.

During exercise or during respiratory distress, the mouth can be used as an additional opening of the respiratory system and then the oropharynx also becomes an air-way.

The pharynx can be split into different regions- the oropharynx, laryngeal pharynx (sometimes referred to as the oesophageal pharynx) and the nasopharynx

Structure and Function

  • Opening of the larynx is on the floor of the pharynx
  • Caudal and dorsal to the laryngeal opening is the opening into the oesophagus
  • In the dorsal region of the nasopharynx there are paired openings into the Auditory (Eustacian) Tubes
  • The lining of the middle ear cavity and auditory tube is continuous with that of the nasopharynx
  • Located between the base of the skull and the first two cervical vertebrae dorsally
  • Walls contain striated muscle
  • Tonsils are present on the lateral walls of the oropharynx
    • Covered by flaps of mucosa
    • Partially visible in the open mouth

Musculature

Constictors

  • Run dorsally to roof of pharynx
  • Rostral constrictor muscles are the pterygopharyngeous and the palatopharyngeous muscles
    • Originate from the pyerygoid region of the skull and the aponeurosis of the soft palate
    • Shorten the pharynx
  • Middle constictor muscle is the hyopharyngeous
  • Caudal constictor muscles are the thyropharyngeous and the cricopharyngeous muscles
    • Originates from the thyroid cartilage of the larynx

Dilators

  • Enclose pharynx laterally and dorsally

Shorteners

  • Enclose pharynx laterally and dorsally

Vasculature

Innervation

Lymphatics

Histology

Species Differences

Canine

  • Tonsils are a compact mass which point away from the lumen of the pharynx

Equine

  • Tonsils are diffuse and raised slightly

Ruminants

  • Tonsils are a compact mass which point towards the lumen of the pharynx

Links

Oropharynx - Anatomy & Physiology

Nasopharynx - Anatomy & Physiology

laryngeal pharynx

BACK TO MUSCULOSKELETAL ANATOMY AND PHYSIOLOGY
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