Difference between revisions of "Pharynx - Anatomy & Physiology"

Revision as of 18:08, 23 December 2010

Introduction

Developing Head - Copyright RVC

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.

Nasopharynx Anatomy - Copyright RVC

Structure and Function

The 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. It is located between the base of the skull and the first two cervical vertebrae dorsally and the larynx ventrally. The mandible, pterygoid muscles and hyoid apparatus are located laterally. Laterally, two pairs of palatopharyngeal arches are present from the soft palate to the oesophagus.

Pharynx Labelled - Copyright C.Clarkson and T.F.Fletcher University of Minnesota

The walls of the pharynx contain striated muscle. During 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. The laryngeal pharynx is separated from the oropharynx by the epiglottis. Tonsils are present on the lateral walls of the oropharynx and are covered by flaps of mucosa. It is partially visible in the open mouth.

The pharynx plays an important role in deglutition.

Soft palate dividing the oropharynx and the nasopharynx - Copyright RVC

Musculature

Muscles that constrict

Muscles that constrict run dorsally to the roof of the pharynx. Rostral constrictor muscles are the hyopharyngeous, pterygopharyngeous and the palatopharyngeous muscles. They originate from the pterygoid region of the skull and the aponeurosis of the soft palate and shorten the pharynx. The middle constictor muscle is the thyopharyngeous muscle. It origniates from the hyoid bone. The caudal constictor muscle is the cricopharyngeous muscle. It originates from the thyroid cartilage of the larynx.

Muscles that dilate

Muscles that dilate enclose the pharynx laterally and dorsally. The dilator muscle is the stylopharyngeous muscle. It originates from the hyoid apparatus and widens the rostral pharynx.

Muscles that shorten

The pterygopharyngeal muscle and palatopharyngeal muscle shorten the pharynx. They enclose the pharynx laterally and dorsally.

Muscles that close the Pharyngeal Arch

The palatopharyngeous muscle also closes the pharyngeal arch.

Innervation

Pharyngeal muscles arise from arch 4. The pharyngeal branch of the vagus nerve (CN X), from the cranial root of the accessory nerve (CN XI). The stylopharyngeous muscle comes from arch 3 and is innervated by the accessory nerve (CN XI). The glossopharyngeal nerve (CN IX) supplies taste to the pharynx.

Histology

Histology of Pharyngeal Tonsil - Copyright RVC

Fibroelastic aponeurosis supports the mucosa. The nasopharynx has pseudostratified columnar epithelium. The oropharynx and the laryngeal pharynx have stratified squamous epithelium. The oropharynx and the laryngeal pharynx also have salivary glands present.

Species Differences

Palatine Tonsil - Copyright C.Clarkson and T.F.Fletcher University of Minnesota

Canine

A single duct connects the nasopharynx to the nasal cavity. The tonsils are a compact mass which point away from the lumen of the pharynx.

Equine

The auditory tube opens into the 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.

Ruminants

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

Links

Oropharynx - Anatomy & Physiology

Nasopharynx - Anatomy & Physiology

laryngeal pharynx

Test yourself with the Oropharynx, Facial Muscle & Pharynx flashcards

Oropharynx Flashcards

Facial Muscles Flashcards

Pharynx Flashcards

Laryngeal Pharynx Flashcards

Nasal Pharynx Flashcards

@@ Line 1: / Line 1: @@
-{{OpenPagesTop}}
+{{review}}
 ==Introduction==
-[[Image:Developing Head.jpg|thumb|right|250px|Developing Head - from [[Oral Cavity Histology resource|Oral Cavity PowerPoint]] ]]
+[[Image:Developing Head.jpg|thumb|right|250px|Developing Head - Copyright RVC]]
 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]].
 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.
-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.
+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 - Anatomy & Physiology|nasopharynx]].
 [[Image:Nasopharynx.jpg|thumb|right|250px|Nasopharynx Anatomy - Copyright RVC]]
 ==Structure and Function==
-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]].
+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 - Anatomy & Physiology|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 - Anatomy & Physiology|nasopharynx]]. It 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]].
 [[Image:Pharynx Anatomy.jpg|thumb|right|250px|Pharynx Labelled - Copyright C.Clarkson and T.F.Fletcher University of Minnesota]]
-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.
+The walls of the pharynx contain striated muscle. During [[Deglutition|swallowing]], the [[Soft Palate|soft palate]] is raised which divides the pharynx into dorsal and ventral sections. The dorsal compartment is the [[Nasopharynx - Anatomy & Physiology|nasopharynx]] and the rostral compartment is the [[Oropharynx - Anatomy & Physiology|oropharynx]]. The [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]] is separated from the [[Oropharynx - Anatomy & Physiology|oropharynx]] by the [[Epiglottis|epiglottis]]. [[Tonsils - Anatomy & Physiology|Tonsils]] are present on the lateral walls of the [[Oropharynx - Anatomy & Physiology|oropharynx]] and are covered by flaps of mucosa. It is partially visible in the open mouth.
 The pharynx plays an important role in [[Deglutition|deglutition]].
@@ Line 19: / Line 20: @@
 ==Musculature==
-Pharyngeal muscles arise from '''arch 4''' except for the stylopharyngeous muscle that comes from '''arch 3'''.
 ===Muscles that constrict===
-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.
+Muscles that constrict run dorsally to the roof of the pharynx. 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 the aponeurosis of the [[Soft Palate|soft palate]] and shorten the pharynx. The middle constictor muscle is the '''thyopharyngeous muscle'''. It origniates from the [[Hyoid Apparatus - Anatomy & Physiology|hyoid bone]]. The caudal constictor muscle is the '''cricopharyngeous muscle'''. It originates from the [[Larynx - Anatomy & Physiology#Thyroid Cartilage|thyroid cartilage]] of the [[Larynx - Anatomy & Physiology|larynx]].
 ===Muscles that dilate===
-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.
+Muscles that dilate enclose the pharynx laterally and dorsally. The dilator muscle is the '''stylopharyngeous muscle'''. It originates from the [[Hyoid Apparatus - Anatomy & Physiology|hyoid apparatus]] and widens the rostral pharynx.
 ===Muscles that shorten===
 The '''pterygopharyngeal muscle''' and '''palatopharyngeal muscle''' shorten the pharynx. They enclose the pharynx laterally and dorsally.
 ===Muscles that close the Pharyngeal Arch===
 The '''palatopharyngeous muscle''' also closes the pharyngeal arch.
 ==Innervation==
-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]]).
+Pharyngeal muscles arise from '''arch 4'''. The pharyngeal branch of the vagus nerve ([[Cranial Nerves - Anatomy & Physiology|CN X]]), from the cranial root of the accessory nerve ([[Cranial Nerves - Anatomy & Physiology|CN XI]]). The stylopharyngeous muscle comes from '''arch 3''' and is innervated by the accessory nerve ([[Cranial Nerves - Anatomy & Physiology|CN XI]]). The glossopharyngeal nerve ([[Cranial Nerves - Anatomy & Physiology|CN IX]]) supplies taste to the pharynx.
 ==Histology==
-[[Image:Pharyngeal Tonsil.jpg|thumb|right|250px|Histology of Pharyngeal Tonsil - from the [[Lymphoid Tissue Histology resource|Lymphoid tissue histology PowerPoint]] ]]
-'''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.
+[[Image:Pharyngeal Tonsil.jpg|thumb|right|250px|Histology of Pharyngeal Tonsil - Copyright RVC]]
+'''Fibroelastic aponeurosis''' supports the mucosa. The [[Nasopharynx - Anatomy & Physiology|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 - Anatomy & Physiology|oropharynx]] and the [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]] also have [[Salivary Glands - Anatomy & Physiology|salivary glands]] present.
 ==Species Differences==
 [[Image:Pharynx Anatomy.jpg|thumb|right|250px|Palatine Tonsil - Copyright C.Clarkson and T.F.Fletcher University of Minnesota]]
 ====Canine====
-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.
+A single duct connects the [[Nasopharynx - Anatomy & Physiology|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.
 ====Equine====
-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.
+The auditory tube opens into the [[Ear - Anatomy & Physiology#Equine Guttural Pouch|guttural pouch]] and the [[Tonsils - Anatomy & Physiology|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.
 ====Ruminants====
-Tonsils are a compact mass which point towards the lumen of the pharynx.
+[[Tonsils - Anatomy & Physiology|Tonsils]] are a compact mass which point towards the lumen of the pharynx.
 ==Links==
-Click here for more information on the [[Oropharynx - Anatomy & Physiology|oropharynx]].
+[[Oropharynx - Anatomy & Physiology|Oropharynx - Anatomy & Physiology]]
+[[Nasopharynx - Anatomy & Physiology]]
+[[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]]
+<br />
+<br />
+==Test yourself with the Oropharynx, Facial Muscle & Pharynx flashcards==
+[[Oral_Cavity_- Anatomy & Physiology_-_Flashcards#Oropharynx_Flashcards|Oropharynx Flashcards]]
+[[Facial_Muscles_-_Musculoskeletal_-_Flashcards|Facial Muscles Flashcards]]
+[[Pharynx - Musculoskeletal - Flashcards|Pharynx Flashcards]]
+[[Pharynx_-_Musculoskeletal_-_Flashcards#The_Laryngeal_Pharynx_Flashcards|Laryngeal Pharynx Flashcards]]
-Click here for more information on the [[Larynx - Anatomy & Physiology#Laryngeal Pharynx|laryngeal pharynx]].
+[[Pharynx_-_Musculoskeletal_-_Flashcards#The_Nasal_Pharynx_Flashcards|Nasal Pharynx Flashcards]]
-{{Template:Learning
-|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]]
-|powerpoints = [[Oral Cavity Histology resource|Histology of the pharynx and larynx]]<br>[[Lymphoid Tissue Histology resource|Histology of lymphoid tissue, including the pharyngeal tonsils]]
-|OVAM = [http://www.onlineveterinaryanatomy.net/sites/default/files/original_media/document/asset_9294_Dog%20pharynx%20PDF.pdf Plastinated Dog Pharynx In Situ]
-}}
-{{review}}
-==Webinars==
-<rss max="10" highlight="none">https://www.thewebinarvet.com/gastroenterology-and-nutrition/webinars/feed</rss>
 [[Category:Respiratory System - Anatomy & Physiology]][[Category:Musculoskeletal System - Anatomy & Physiology]]
-[[Category:A&P Done]]
+[[Category:To Do - A&P]]