Week 5: ENT 2 (anatomy of nose, mouth and throat) Flashcards
(52 cards)
1
Q
function of the nose
A
- Smell and taste
- Breathing- route for inspired air
- Filters inspired air trapping particle sin nasal hair and mucous
- Moistens (humidifies) and warms
- Resonating chamber for speech
2
Q
anatomy of the nasal cavity
A
- External nose (vestibule) from the external nose to the nasopharynx
- Anterior nares= nostrils (apertures)
- Posterior nasal apertures (choanae)
3
Q
external nose
A
- Made up of cartilage (near the nostrils) and bone
- Important bone = nasal bone (paired bone)
- Clinical correlates
- Prominence of nasal bone makes them susceptible to fracture in facial injury
4
Q
vestibule
A
Lined with skin containing sebaceous/sweat glands and hair filters inspired air
5
Q
nasal cavity
A
Has bony boundaries and is divided into left and right by midline septum
6
Q
the nose has 2 lateral walls - describe their structure
A
- Irregular due to presence of bony projections (conchae/ turbinate’s)
- Superior (part of ethmoid)
- Middle (part of ethmoid)
- Inferior (other bone
- These creates meatuses
- Superior
- Middle
- Inferior
7
Q
opening sunder the meatuses allows for
A
drainage of the
- Paranasal air sinus in nasal cavity
- Nasolacrimal duct in nasal cavity
8
Q
Why does the nose have this irregular anatomy?
A
- slows airflow by causing turbulence of airflow
- increases surface area over which air passes
- doesn’t always require immediate intervention
9
Q
bones whcih form the food of the nasal cavity
A
frontal bone
nasal bone
ethmoid bone (cribriform plate)
sphenoid
10
Q
the nasal roof can be used to
A
access parts of the brain found ont he cranial floow
e.g. Transsphenoidal surgical approach- e.g. gaining access to the pituitary gland via the sphenoid bone
11
Q
medial wall of the nasal cavity- the septum
A
- Consists of a bony and cartilaginous part
- Anterior= septal cartilage
- Posterior= perpendicular plate of the ethmoid bone and the vomer bone
12
Q
if you dont treat a septal heamtoma what forms and why
A
saddle nose deformity
untreated septal haematoma e.g. caused by trauma leads to avascular necrosis of cartilaginous septum
13
Q
nerve innervation of the nasal cavity
A
- V1- Ophthalmic
-
V2- Maxillary
- Majority of nasal cavity (particularly lateral wall) supplies by V2
- V3- mandibular
14
Q
lining of the nasal vaity
A
Vestibule lined by skin
Deeper lined with mucus membrane - very vascular
- olfactory region
- respiratory region
15
Q
olfactory region
A
- Olfactory mucous membrane
- Contains dendrites of olfactory nerves
- Covers over roof of the nasal cavity (including superior concha/superior part of the septum)
- Contains dendrites of olfactory nerves
16
Q
Respiratory mucous membrane
A
- Pseudostratified columnar epithelium
- Rich in goblet cells
- Filters (mucous and cilia)
- Humidifies and warms(rich blood supply)
17
Q
Rich blood supply to the nasal mucosa
A
Allows for warming and humidification of inspired air
- Mucosa and blood vessels are easily injured
- Nose bleed (epistaxis)
18
Q
arterial supply of the nose includes
A
ophthalmic artery
maxillary artery
19
Q
ophthalmic artery blood supply to the nose
A
Ethmoidal arteries (anterior and posterior)
- feed into Little’s / kiesselbachs plexus
20
Q
maxillary artery branches supplying the nose
A
- Form a rich arterial anastomoses in the anterior septum (Keisselbachs plexus)
- Most common source of bleeding in epistaxis (e.g. picking of nose)
- Easily treatable with simple first aid measure- pinching nose
- Usually just one sided
-
Sphenopalatine artery
- Small proportion of nosebleeds
- Potentially more serious and difficult to reach(harder to reach to tamponade
- Bleeding in both nostrils
- Small proportion of nosebleeds
21
Q
venous drainage of npse
A
- Form a rich arterial anastomoses in the anterior septum (Keisselbachs plexus)
- Most common source of bleeding in epistaxis (e.g. picking of nose)
- Easily treatable with simple first aid measure- pinching nose
- Usually just one sided
-
Sphenopalatine artery
- Small proportion of nosebleeds
- Potentially more serious and difficult to reach(harder to reach to tamponade
- Bleeding in both nostrils
*
- Small proportion of nosebleeds
22
Q
paranasal sinuses: name
A
1. Frontal air sinuses (can have 2,3 or 4)
2. Ethmoid air sinuses
3. Maxillary air sinuses- most common infection due to gravity and draining mucus
4. Sphenoidal air sinuses
23
Q
what are paranasal sinuses
A
- Air filled spaces that are extension of the nasal cavity
- Rudimentary or absent at birth
- Lined with respiratory mucosa
- Ciliated and secretes mucous
- Named according to the bone in which they are found
- Various functions – humidify and warm inspired air
- Reduce weight of the skull
- Drain into the nasal cavity via small channels (ostia in middle conchia) into a meatus
- Most in the middle meatus
- Infection of nasal cavity involving sinuses (sinusitis)
- Maxillary sinus most commonly infected
24
Q
importnant anatomical relations of paranasal sinuses include
A
nasal cavity, orbit and anteriro cranial foss
- roots of upper teeth can progest into maxiallary sinus
25
sensory innervation of paranasal sinuses
from the trigeminal (V)
* Va (frontal, ethmoidal and sphenoid sinus)
* Vb (maxillary sinus)
26
Nasal cavity separate to oral cavity=
the hard and soft palate
* Tip of soft palate= uvula
27
how many teeth
32
28
area between lips and teeth
vestibule
29
palatoglossal and palatopharyngeal arches
(Mc Donald’s signs)
* Where tonsils sit within
30
salivary glands
x3 paiers
* parotid
* submandibular
* sublingual
31
parotid glands
* Lies anterior to the SCM and ear
* Behind the masseter and zygomatic arch
* Duct opens up in the upper region of the oral cavity**- Stenson’s duct** (near upper 2nd molar)
* produces 25% of all saliva
* serous consistency with lots of enzymes
32
sublingual gland
* Lie under the tongue
* 5% of saliva
* More mucous saliva and less enzymes than the parotid gland
33
submandibular gland
* Sits below the mandible and in submandibular triangle
* Produces a mixed saliva
* Serous
* Mucous
* Biggest contributor volume wise- 70% of all saliva
34
production of saliva
**Exocrine structure of the salivary gland**
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* Acinus is where the saliva is produced
* Isotonic with plasma
* Isotonic solution passes out of the acinus due to myoacinus epithelial cells which contract the acinus to move saliva into the duct
* Once in the ductal region , ductal cells use transporters to move Na+ and Cl- out of the solution and K+ and HCO3- into the solution
* Producing a **hypotonic** solution near the end of the duct (removal of ions \>secretion)
* The amount of modification by the ductal cells depends on how quickly the saliva is moving through the ductal system
* Basal level- most hypotonic solution
* When eating the solution moves through much quicker, less contact with ductal cells- smallest change to the tonicity of the isotonic solution **(more secretion of HCO3- when active saliva production**
35
tongue made up of
intrinsic and extrinsic muscles
36
intrinsic muscles of the tongue
* Intrinsic muscle (not attached to other muscles except other intrinsic muscles)
* 4 pair muscles
* Longitudinal
* Transverse
* vertical
* Motor innervation – **hypoglossal nerve**
37
extrinsic muscles of the tongue
* arise from other structures and insert into tongue
* Genioglossus
* Hyoglossus
* Styloglossus
* Motor innervation: hypoglossal nerve
* Palatoglossus
* Motor innervation (vagus nerve)
38
sensory supply of the tongue
* Divides tongue into
* Anterior 2/3
* Sensation- trigeminal (V3)
* Taste- facial
* Posterior 1/3
* Sensation and tase- glossopharyngeal
39
throat - pharynx divided into
* **Nasopharynx**
* Behind nasal cavity
* **Oropharynx**
* Behind oral cavity
* **Laryngopharynx**
* Behind larynx
40
the nasopharynx- upper pharynx
* Pink part in the photo
* Behind the nasal cavity
* borders
* Base of skull- upper border
* C1,C2- posterior border
* Nasal cavity- anterior border
* Contains
* Pharyngeal tonsil e.g. adenoids
* glossopharangeal sensory supply
41
the oropharynx- middle pharnx
* Yellow part on photo
* Starts where the nasopharynx end
* Borders
* Soft palate to epiglottis
* Anterior- oral cavity
* Posterior (C2,C3)
* Contains
* Palatine tonsils
* glossopharangeal supply
42
palatine tonsils
**collection of lymphoid tissue in the oropharyngeal mucosa**. They form part of Waldeyer's ring
**function: preventing infection in the respiratory and digestive tracts by producing antibodies (B and T cells) that help kill infective agents**
43
laryngopharynx- lower pharynx
* Blue part on photos
* Borders
* Oropharynx to oesophagus
* Epiglottis to cricoid cartilage
* Anterior- larynx
* Posterior (C4, C5, C6)
* Contains
* Piriform fossa
* pharyngeal branches of the vagus nerve
44
piriform fossa
Epiglottis (flap on right photo) acts as a director of flow of fluid and water into the piriform fossa into the oesophagus instead of the trachea
45
**General overview of muscle arrangements in the pharynx**
3x longitudinal muscles
* Stylopharyngeus
* Palatopharyngeus
* Salpingopharygeus
3x constrictors (circular)
46
**Stylopharyngeus**
* Originates from the styloid process and goes down to the posterior border of the thyroid cartilage
* **Innervation-** glossopharyngeal nerve (CN IX)
47
palatopharyngeys
* Originates from the hard palate and extends down to the attach to the posterior border of the thyroid gland
* Pharyngeal branch of vagus (CN X)
48
salpingopharyngeaus
* Originates from the cartilaginous part of ET- merges with the palatopharyngeus
* Pharyngeal branch of vagus (CN X)
49
**Pharyngeal constrictors**
**X3 circular (more semi-circular) muscles all insert on the pharyngeal raphe)**
* Superior pharyngeal constrictor
* Origin – pterygomandibular raphe
* Middle pharyngeal constrictor
* Origin- hyoid bone
* Inferior
* 2 parts
* Thyropharyngeal (origin- thyroid cartilage)
* Cricopharyngeal (origin- cricoid cartilage
* All supplies by the vagus nerve
50
aim of pharngeal constrictors
* **Constrict walls of pharynx when swallowing**
51
**General overview of nerve innervation of pharynx**
* **Pharyngeal plexus**
* Located mainly on surface of middle constrictor muscle
* Vagus, glossopharyngeal and cervical sympathetic nerve
* **Motor**
* CNX -Vagus innervates all muscles
* Except stylopharyngeus (glossopharyngeal nerve (CN IX))
* **Sensory**
* Nasopharynx (glossopharyngeal nerve CN IX)
* Oropharynx ( glossopharyngeal nerve CN IX)
* Laryngopharynx (vagus nerve CNX)
52
swallowing
**1) Oral stage**
* Voluntary
* Tongue touching hard-palate
**2) Pharyngeal phase**
* Involuntary
* Tongue touching hard palate
* Soft palate elevation
* Dangerous stage- shared airway space
* Need to protect airway
* By shortening longitudinal muscles- elevate larynx and pharynx→ widening it
* Closure of epiglottis (sealing the airway)
**3) Oesophageal phase**
* Relaxes upper oesophageal sphincter
* Rapid peristalsis
* Lower oesophageal sphincter relaxes and bolus goes into stomach
