Lecture 16 and (17?): Pharynx and Larynx Flashcards
1
Q
What are the 3 divisions of the pharynx ?
Where are they found?
A
The pharynx is formed by skeletal muscles and fascia.
- This musculofascial half-cylinder extends from the base of the skull to upper border of oesophagus (C6 vertebral level).
- It can be divided into three regions:
- Nasopharynx (behind nasal cavities),
- Oropharynx (behind oral cavity);
- Laryngopharynx (behind superior part of larynx).
2
Q
The highest point of the pharynx is…
A
At the base of the skull
3
Q
Describe the Pharyngeal wall
A
The pharyngeal wall is attached to bone and cartilage and to ligament superiorly and anteriorly.
The two sides meet posteriorly in the midline at the pharyngeal raphe.
The muscles of the pharynx are organised into two groups based on the direction of their fibres relative to the pharyngeal wall: constrictors (circular) and longitudinal (vertical).
4
Q
What are the names of the constrictor muscles?
Describe the anatomy of these muscles
A
There are three constrictor muscles: superior, middle and inferior.
-
Anatomy:
- They are C-shaped muscle with anterior opening and posterior closing.
- The two sides meet posteriorly in the middle at the pharyngeal raphe
- They overlap each other in a fashion resembling the walls of three flowerpots stacked one on the other.
- The gaps between the muscles are reinforced by fascia and provide routes for strucrures to pass through the wall.
- (the bottom is open and so is the anterior side of the superior constrictor muscle)
5
Q
Describe the function and innervation of the CONSTRICTOR muscles
A
Function: contract sequentially from top to bottom thus peristalsis of food bolus through pharynx and into esophagus.
Innervation: vagus nerve (CN X)
A special band of muscle (palatopharyngeal sphincter) originates from anterolateral surface of soft palate and circles inner aspect of pharyngeal wall, therefore belongs to inner aspect of superior constrictor.
6
Q
A special band of muscle (palatopharyngeal sphincter) originates from __________and circles ___________, therefore belongs to __________________\_
A
A special band of muscle (palatopharyngeal sphincter) originates from anterolateral surface of soft palate and circles inner aspect of pharyngeal wall, therefore belongs to inner aspect of superior constrictor.
7
Q
Name and Describe the Anatomy of the Longitudinal muscles
A
Longitudinal muscles include 1) salpingopharyngeus, 2) palatopharyngeus and 3) stylopharyngeus.
-
Anatomy:
- From their sites of origin (base of skull), they run downward and attach into pharyngeal wall.
- (Help stabilise the constrictor muscles)
- From their sites of origin (base of skull), they run downward and attach into pharyngeal wall.
8
Q
Label
A
1) Superior constrictor
2) Middle constrictor
3) Inferior constrictor
9
Q
Label
A
1) Salpingopharyngeus
2) Palatopharyngeus
3) Stylopharyngeus
(Longitudinal muscles)
10
Q
Label
A
1) Pharyngeal tonsil
2) Opening of pharyngotypmaic tube
3) Palaoglossal arch
4) Palatine tonsil
5) Palatopharyngeal arch
11
Q
Describe the Function and Innervation of Longitudinal muscles
A
- Function: elevate wall and/or assist swallowing; pull up and over food bolus and push it through pharynx to esophagus.
- Innervation: vagus nerve (CN X), except stylopharyngeus by glossopharyngeal nerve (CN IX).
12
Q
Where (name the bones) does the superior constrictor attach to the skull?
A
1) Sphenoid
2) Petrous part of Temporal bone
3) Pharyngotympanic tube
4) Pharyngeal tubercle (occipital)
13
Q
Where does the Superior Constrictor Mucle attach anteriorly?
A
Pterygomadibular raphe
14
Q
Where does the Middle Constrictor Muscle attach anteriorly?
A
Stylohyoid ligament
Lesser and greater horn of the Hyoid
15
Q
Where does the Inferior Constrictor Muscle attach ?
A
Oblique line (where the strap muscles also attach)
16
Q
Why do the constrictor muscles have such small attachments?
A
There are lots of structures running between these
17
Q
Where do the constrictor muscles of the pharynx attach?
A
Superior Constrictor
- Posterior attachment
- Pharyngeal raphe
- Anterior attachment
- Pteryomandibular raphe
- Adjacent bone on the manidble
- Pterygoid hamulus
Middle constrictor
- Posterior attachment
- Pharyngeal raphe
- Anterior attachment
- Upper margin of greater horn on hyoid bone
- Adjacent margins of lesser horn
- Stylohyoid ligament
Inferior constrictor
- Posterior attachment
- Pharyngeal raphe
- Anterior attachment
- Oblique line of thyroid cartilage
- Cricoid cartilage
18
Q
Describe the Facia in the neck
Which one in particular is important to the pharynx?
A
1) Buccopharyngeal
2) Pharyngobasilar Fasica = fascia that runs deep to the mucosa- runs between the mucosa and the constrictor muscle- so trying to stabilise the constrictor muscles.
(below= what?)
Deep fascia of the neck divides into
- Superficial (investing)
- Middle (pretrachel)
- Deep (prevetebral) = Buccopharyngeal Fascia
19
Q
What structures help stabilise the constrictor muscles?
A
1) longitudinal muscles
2) Pharyngobasilar fasica
20
Q
What does the gap above the superior constrictor divide?
A
Buccinator and Superior Constrictor
21
Q
What goes through the gaps next to the constrictor muscles?
A
Structures Passing Through Gaps (Exam: Oropharyngeal Triangle)
Gaps between muscles are reinforced by fascia and provide routes for structures to pass through wall. Understanding their attachment is important.
Above superior constrictor:
- Tensor veli palatini muscle (DNTK)
- Levator veli palatini muscle (DNTK)
Between superior and middle constrictors, and posterior border of mylohyoid (oropharyngeal triangle):
- stylopharyngeus muscle,
- glossopharyngeal nerve (CN IX)
- lingual nerve and vessels.
Between middle and inferior constrictors:
- Internal laryngeal nerve (branch of superior laryngeal nerve) and vessels
Below the inferior:
- Recurrent laryngeal nerve
- inferior laryngeal vessels
22
Q
If you see folds in the oral cavity there is always……..
A
A Muscle running underneath the mucosa
23
Q
What is the clinical implication of adenoid tonsils?
A
Adenoid tonsil = Pharyngeal tonsil
It fills the whole nasopharynx.
It blocks the nasal cavity from the back. Also the opening for the eustachian tubeopens here.
The adenoid tonsil can get big and block this area
This can cause middle ear infections, cannot breathe through the nose, make noise when breathing etc.
24
Q
Name the different tonsils
A
1) Pharyngeal/adenoid tonsil
* Covers the nasopharynx and can block the pharyngotympanic/eustachian tube.
2) Palatine tonsil
* Sits between oral pharynx and oral cavity
25
When we put the angiotube in. where does it go?
* Through the nose
* Into the Nasopharynx
* Down to the oestrophagus
* Runs through the pharynx
26
What are palatine tonsils?
The tonsils (palatine tonsils) are a pair of _soft tissue masse_s located at the rear of the throat (pharynx).
Each tonsil is composed of _tissue similar to lymph nodes_, _covered by pink mucosa_ (like on the adjacent mouthlining). Running through the mucosa of each tonsil are p_its, called crypts._
27
Diagnose
_Clinical: Adenoids_
**Adenoids** are _enlarged pharyngeal tonsil_ (lymphoid tissue) at base of skull / roof of pharynx
28
Describe the boundaries of the different boarders of the pharynx
* **Nasopharynx**:
* _behind posterior apertures_ (choanae) of nasal cavities,
* _above soft palate_
* **Oropharynx**:
* _posterior to oral cavity_,
* _inferior to soft palate,_
* _superior to upper margin of epiglottis_
* **Laryngopharynx**:
* extends from _superior margin of epiglottis,_
* to _top of esophagus_ at level of vertebra C6
29
Describe the blood supply to the pharynx
**_Upper part_**: branches of _external carotid artery_ (lingual, maxillary, facial, ascending pharyngeal artery)
**_Lower part:_** branches of _subclavian artery (i_nferior thyroid artery of thyrocervical trunk).
_Note:_ Palatine tonsil supplied by tonsillar branch of facial artery.
30
Describe the venous drainge and lymphatics of the pharynx
**Venous Drainage**
* **_Superior_**: drain into _pterygoid plexus of infratemporal fossa_ (*to facial & superficial temporal, then to internal jugular*)
* **_Inferior_**: drain into _facial and internal jugular vein._
**Lymphatic Drainage** *(Zone 2-5, No Zone 1)*
* **_Lymphatic vessels drain_** into _deep cervical lymph nodes_ (paratracheal, infrahyoid and retropharyngeal nodes)
* _Note:_ palatine tonsils drain into jugulodigastric nodes.
31
Describe the Innervation of the Pharyngeal muscles
**Innervation**
Motor and sensory innervation is mainly by _pharyngeal plexus_ (branches of vagus [CN X] and glossopharyngeal [CN IX]).
* **_Motor_**:
* all innervated by _vagus nerve (CN X)_
* except for stylopharyngeus by _glossopharyngeal (CN IX)._
* **_Sensory_**:
* laryngopharynx (vagus [CN X])
* oropharynx (glossopharyngeal nerve [CN IX])
* nasopharynx (maxillary nerve [V2])
32
* **_Motor_**:
* all innervated by ______ nerve
* except for _______ by ________ nerve.
* **_Sensory_**:
* laryngopharynx (\_\_\_\_ nerve)
* oropharynx (\_\_\_\_\_ nerve)
* nasopharynx (\_\_\_\_\_\_nerve)
**Innervation**
Motor and sensory innervation is mainly by pharyngeal plexus (branches of vagus [CN X] and glossopharyngeal [CN IX]).
* Motor:
* all innervated by vagus nerve (CN X)
* except for stylopharyngeus by glossopharyngeal (CN IX).
* Sensory: \*\*\*
* nasopharynx (_maxillary nerve [V2])_
* oropharynx (_glossopharyngeal nerve [CN IX]_)
* laryngopharynx (_vagus [CN X_])
33
What is the epiglottis?
The epiglottis is a flexible flap at the superior end of the larynx in the throat. It acts as a switch between the larynx and the esophagus to permit air to enter the airway to the lungs and food to pass into the gastrointestinal tract.
34
Where is the Larynx found?
The larynx is a musculoligamentous structure with a cartilaginous framework located _above the lower respiratory tract_. It continue_s inferiorly with the trachea a_nd _superiorly opens into laryngopharynx._
35
The larynx is a musculoligamentous structure with a cartilaginous framework located above the\_\_\_\_\_\_\_\_\_\_\_.
It continues inferiorly with the \_\_\_\_\_\_\_\_and superiorly opens into \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_..
The larynx is a musculoligamentous structure with a cartilaginous framework _located above the lower respiratory tract._
It continues inferiorly with the _trachea_ and superiorly opens into _laryngopharynx_.
36
Pharynx had a \_\_\_\_\_framework, Larynx has a ________ framework
Pharynx had a Skeletal framework, Larynx has a Cartilinagous framework
37
What cartilages are the larynx formed by?
1) **_Epiglottis_**
2) _**Thyroid cartilage\*\***_ (thyroid sits below it- not at the thyroid cartilage) \*\* - has an oblique line (site of attachment of constrictor muscles, deeper muscles of infrahyoid muscles)
3) **_Cricoid cartilage \*\*_**(sits below the thyroid cartilage. It is at the C6 level)
* Superior and Inferior horn
* Facet for cricoid (where they join with others)
4) _**Arytenoid cartilage \***_\*(sits above the cricoid cartilage)
5) Cunneiform cartilage (less important- sit in the fascia)
6) Corniculate cartilage (less important- sit in the fascia)
38
What is another name of 'adam's apple'?
Laryngeal prominence
39
What are the ligaments in the Larynx?
**Extrinsic Ligaments**
* _Thyrohyoid membrane_ \*\* is a tough fibroelastic ligament that spans between _thyroid cartilage_ below and _hyoid bone above._
* *Posterior borders are thickened to form lateral thyrohyoid ligaments. Triticeal cartilage in each lateral thyrohyoid ligament.*
* *The anterior midline is thickened to form the median thyrohyoid ligament.*
* *It has a _hole_ which the internal branch of the sup laryngeal nerve and associated artery runs.*
* _Hyo-epiglottic ligament_ extends from _epiglottis midline_ anterosuperiorly to _hyoid bone._
* _Cricotracheal ligament_ runs from _cricoid cartilage_ to the _first tracheal cartilage,_ important for _tracheostomy_.
**_Intrinsic Ligaments_**
* _Fibroelastic membrane_ (intrinsic ligaments) links together laryngeal cartilages and completes laryngeal cavity. It is composed of two parts.
* _1) Cricothyroid ligament_ (lower) is attached to _cricoid cartilage_ inferiorly, and _thyroid cartilage_ superiorly.
* Superiorly, thickened to form _vocal ligament_ (more medial), which is under _vocal fold (true vocal cord)_.
* Anteriorly, midline thickened to form _median cricothyroid ligament_, which can be perforated via _cricothyroidotomy_ to establish _emergency_ airway.
* _2) Quadrangular membrane_ (upper) runs between lateral epiglottis and anterolateral arytenoid cartilage
* Inferiorly is thickened to form _vestibular ligament_ (more lateral), which is under _vestibular fold (false vocal cord)_
40
There is an important hole of n extrinsic ligament
1) Name the ligament
2) What goes through this?
_Thyrohyoid membrane_
The whole is an aperture for internal branch of _superior laryngeal nerve_ and _associated artery._
41
What do the sup and inf thyroid arteries supply?
**_Superior Thyroid artery_**: Thyroid and the larynx (upper part)
**_Inferior Thyroid artery_**: Thyroid and the larynx (lower part)
42
What ligmanet makes up the "true vocal cord"?
Thickening of the upper part of the Cricothyroid ligament
43
Label from 1-8
1) Thyroid cartilage
2) Epiglottis cartilage
3) Arytenoid cartilage
4) Cricoid cartilage
5) Vestibular ligament
6) Quadrangular membrane
7) Cricothyroid membrane
8) Vocal ligament
44
Label 9-11
9) Cricothyroid
10) Transverse arytenoid
11) Posterior crico-arytenoid
45
What is the true and what is the false vocal cord? \*\*
When the artyenoid cartilage moves, it shuts and opens both the false and true vocal cords
The F_alse/vestibular ligamen_t sits more _lateral_ to the true vocal cord (because thte true one is the one we use when we're breathing- abduct to talk)
When you intubate your patient, do not damage the vocal cords- go between the 2 vocal cords
**_True_**:
- Thickening of the superior part of the _cricothyroid ligament_ **_(Vocal Ligament)_**
- Runs between the a_rytenoid cartilage_ and the anterior part of the _thyroid cartilage_
**_False_**
-Inferiorly is thickened part of _Quadrangular membrane_ to form _v**estibular ligament**_ (more lateral), which is under _vestibular fold (false vocal cord)_
(Vestibular ligament)
- Runs between the _epiglottis_ and the t_hyroid carilage_ and the upper part of the _arytenoid cartilage_
- Thickening is between the a_nterior part of the thyroid carilage_ to the _arytenoid cartilage_
46
Describe the movement of the larynx cartilages
_Cricothyroid_ joints enable t_hyroid cartilage_ to _move forward_ and _tilt downward_ on _cricoid cartilage_ (lengthens and puts tension on vocal ligaments)
_Crico-arytenoid joints_ enable a_rytenoid cartilages_ to r_otate (by pivoting)_, _slide away/toward each other_ (abduct and adduct the vocal ligaments)
47
Label
1) Cricoid cartilage
2) Arytenoid cartilage
3) Thyroid cartilage
4) Glottis
5) Vocal cord
6) Superior horn of thyroid cartilage
48
All intrinsic laryngeal muscles are innervated by \_\_\_\_\_\_\_\_\_\_\_\_\_except ___________ which is innervated by the ________ nerve
All intrinsic innervated by _recurrent laryngeal nerve_ except _cricothyroid_ (superior laryngeal nerve)
49
Label
1) Vocal cord
2) Vestibular fold (false vocal cord)
3) Ary-epiglottic fold
50
Describe the divisions of the larynx
The larynx is divided into three areas by pairs of mucosal folds, the vestibular and vocal folds.
These divisions are
(1) _vestibule;_
_(2) middle part (very thin and between folds);_
_(3) infraglottic space_.
51
Label 1-8
1) Tongue
2) Epiglottis
3) Ary-epiglottic fold
4) Cuneiform tubercle
5) Corniculate tubercle
6) Vestibular fold
7) Vocal fold (true vocal cord)
8) Rima glottidis (opening between vocal cords)
52
Label 9-12
9) Laryngeal inlet
10) Vestibule
11) Piriform recess
12) Laryngopharynx (closed)
53
If someone has a fish bone stuck in their throat, where is it likely to be?
Piriform recess- on the _lateral to the ary-epiglottic fold_
The piriform recess lies on either side of the laryngeal inlet. It is bounded medially by the aryepiglottic fold and laterally by thyroid cartilage.
It is a common place for food or foreign bodies to become trapped (e.g. a fish bone).
54
What is the piriform recess?
The _piriform recess_ lies on either side of the l_aryngeal inlet_. It is bounded medially by the **_aryepiglottic fold_** and laterally by thyroid cartilage.
It is a common place for _food or foreign bodies to become trapped_ (e.g. a fish bone).
Why do we have it? - Piriform recess makes up most of larynx in babies. When they're lying down and drinking milk, this helps them drink milk fast. Larynx is small, so the PR is larger (comparatively) so milk can go fastly into the oesophagus.
55
What are the extrinsic muscles of the larynx?
**Extrinsic Muscles** **(Origin/Insertion Outside Layrnx)**
* _Cricohyoid (DNTK)_
* _Posterior crico-arytenoid \*\*_
* Essential! Only muscle that opens the airways
* Innervated by recurrent laryngeal nerve
* _Vocalis muscle_
* __Need to move the vocal cord
56
What muscle opens the airways?
Posterior Crico-arytenoid
MUST KNOW - keeps us alive
57
What is the name of the sapce between the two vocal cords?
Rima glottidis is the space between two adjacent true vocal cords (true vocal cords produce sounds when they are adducted and air is forced between them).
Rima vestibuli is the space between two adjacent vestibular folds (false vocal cords).
58
What happens when we're swallowing?
Epiglottis shuts the door of the larynx. Epiglottis swings downwards to cover glottis (narrow laryngeal inlet) and open esophagus.
Babies cannot use the epiglottis because it comes up to the nasopharynx (too high)
59
Describe the blood supply of the laryngeal muscles
What is the clinical significance of this?
**Blood Supply**
1. _Superior laryngeal artery_ from _superior thyroid (originating from external carotid artery)_
* Above the vocal cords
2. _Inferior laryngeal artery_ from _inferior thyroid (originating from subclavian artery)_
* Below the vocal cords
When you are removing the thyroid, you have to make sure you _ligate the Superior Thyroid right at the thyroid gland._ If you ligate the Superior thyroid artery at the origin, it cannot supply the larynx.
60
Describe the Venous and Lymphatic drainage of the larynx
**Venous Drainage**
1. _Superior laryngeal veins_ drain into _superior thyroid veins_, which in turn drain into _internal jugular vein_.
2. _Inferior laryngeal veins_ drain into _inferior thyroid veins_, which in turn drain into _left brachiocephalic vein_.
**Lymphatic Drainage**
1. Above vocal folds: drain into _deep cervical nodes_ associated with _bifurcation of common carotid artery_
2. Below vocal folds: drain into _deep nodes (paratracheal)_ associated with _upper trachea_.
61
Describe the Innervation of the Larynx
Sensory and motor innervation of larynx is by two branches of _vagus nerve,_ which are 1) _recurrent laryngeal nerves and 2) superior laryngeal nerves._
* **_Recurrent laryngeal nerve_** supplies motor to _all intrinsic muscles (except cricothyroid)_ and _sensory below vocal folds_.
* **_Superior laryngeal nerve_** divides into internal and external laryngeal nerve:
* _External_ laryngeal nerve: motor to _cricothyroid_ muscle;
* _Internal_ laryngeal nerve: mainly _sensory_ _above vocal folds_.
62
Recurrent laryngeal nerve supplies \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Superior laryngeal nerve divides into ________________ and supplies \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
**_Recurrent laryngeal nerve_** supplies motor to a_ll intrinsic muscles_ (except cricothyroid- not important) and sensory b_elow vocal folds._
**_Superior laryngeal nerve_** divides into _internal and external laryngeal nerve:_
* _External laryngeal nerve_: motor to c_ricothyroid muscle;_
* I_nternal laryngeal nerve:_ mainly sensory _above vocal folds._
63
Label
1) Right common carotid artery
2) Right vagus nerve
3) Right recurrent laryngeal nerve
4) Right subclavian artery
5) Left common cartoid artery
6) Left vagus nerve
7) Thyroid Gland
8) Left recurrent larygen nerve
9) Left subclavian artery
10) Larynx
64
What is a cricothyroidotomy and tracheostomy?
**Tracheostomy** is performed to _relieve airway obstruction_ or protect the airways and can be emergent or planned.
**Cricothyroidotomy** is a safer alternative in an _emergency situation_. These procedures may be technically _challenging due to patient facto_rs (e.g. obese patients or those with a short neck).
65
Describe Tracehostomy
What could be damaged in this procedure?
The patient is suitably prepared and positioned. Palpable midline structures are used as reference points. These points are _(from inferior to superior): suprasternal notch, cricoid cartilage and superior thyroid notch_.
* A horizontal incision (in relation to midline) is made _midway between suprasternal notch and cricoid cartilage_.
* Skin, platysma and superficial veins (communicating veins between anterior jugular vein) are divided together with investing layer of deep fascia of neck.
* Strap muscles are retracted laterally to expose thyroid isthmus. Pretracheal fascia encloses thyroid isthmus, which usually overlies second and third tracheal ring. Thyroid isthmus with its fascia are divided and overseen before _incising second and third tracheal rings_. First tracheal ring must be avoided!
It is important to stick to the midline in order to _avoid injuring 1) **recurrent nerves,** **2) carotid sheath** and **3) inferior thyroid veins**_. In an emergency, a vertical midline incision may be used rather than a transverse cervical incision.
66
Describe the Cricothyroidotomy
What are some structures that might be damaged?
Tracheostomy is performed to relieve airway obstruction or protect the airways and can be emergent or planned.
**_Cricothyroidotomy_** is a s_afer alternative in an emergency situation._ These procedures may be technically challenging due to patient factors (e.g. obese patients or those with a short neck).
* Surgical cricothyroidotomy and needle cricothyroidotomy are important emergency procedures in advanced life support. In surgical cricothyroidotomy, patient is suitably positioned with neck extended. After palpating _gap between_ _inferior thyroid notch and cricoid cartilage in midline_, a transverse incision is made down to and then _through cricothyroid membrane_ in order to insert a tube. Needle cricothyroidotomy is a temporizing measure.
* *Once the patient has been stabilsed, a formal tracheostomy can be performed for definitive airway management.*
* Some structures may be at risk of _injury such as **1) branch of superior thyroid artery**_ (runs over cricothyroid membrane). Other complications include **2( _injury to the trachea or esophagus_** etc.
67
What are the divisions of the larynx?
The larynx is divided into three areas by
pairs of mucosal folds, the vestibular and
vocal folds. These divisions are:
1) Vestibule.
2) Middle part (very thin and between folds).
3) Infraglottic space.
