Anatomy and pattern recognition of the upper respiratory system and neckNormal and abnormal

Question 1

Revision of the respiratory system

Answer 1

Our cells need O2 to produce ATP. It is vital to life

We also need to eliminate the toxic bi-product of the cellular processes – CO2

Our respiratory and cardiovascular system work in collaboration to exchange and transport gases

Failure of this process due to pathology will lead to rapid cell death and a build-up of toxins

Secondary functions of the respiratory system include:
Helps to regulate PH alongside the kidneys
Smell receptors
Filters and moistens inspired air
Sound production
Release of heat and some water

Question 2

Respiratory system: devisions

Answer 2

Divided into:
Upper:
Nose (nasal cavity and paranasal sinuses)
Pharynx
Lower:
Larynx
Trachea
Bronchi
Lungs

Conducting system:
Transport of air: filter, warm, moisten
Respiratory portion:
Gas exchange between air and blood

Question 3

Nose: description

Answer 3

Has 3 main functions
Warming, moistening and filtering inhaled air.
Detecting smell.
Modifying speech and sounds through resonance.
It is the only part of the respiratory system that is externally visible.
Is often divided into
External – nose
Internal – nasal cavity

Question 4

External nose

Answer 4

Muscle and skin supported by bone/ hyaline cartilage framework
Lined internally with mucous membrane
External opening – nares

Bones:
Paired nasal bones (bridge)
Frontal bone (root)
Maxilla

Hyaline cartilage:
Septal cartilage (midline)
Lateral processes of septal cartilage
Alar cartilages (form flared rim of nares)

Shape of nose dependent on cartilage structure

Question 5

Nasal cavity

Answer 5

Paired spaces either side of midline
Upper part of respiratory tract between external nares and nasopharynx thought the choanae

Wedge-shaped (apex anteriorly)
Formed by complex bone and cartilage framework
Have floor, roof, and medial/lateral walls

Separated;
From each other by nasal septum
From oral cavity by hard palate
From the cranial cavity by the frontal, ethmoid, and sphenoid bones

Medial wall/division between cavities called nasal septum

Anteriorly formed by septal cartilage

Posteriorly formed by vomer bone and perpendicular plate of ethmoid bone

Question 6

Nasal cavity: regions

Answer 6

3 regions:

Vestibule:
Within nares/external nose
Lined with skin
Coarse hairs filter large particles

Respiratory:
Largest
Very neurovascular (capillaries warm air)
Respiratory epithelium

Olfactory:
Contains olfactory (smell receptors)
Lined with olfactory epithelium

Question 7

Nasal cavity: Respiratory epithelium

Answer 7

Secretes (1litre per day):
Mucous
Watery-fluid containing lysozyme (antibacterial enzyme)
Defensins (natural antibiotics)
Cilia propel mucous and ‘foreign particles’ towards throat; swallowed and digested

Question 8

Nasal cavity – lateral walls

Answer 8

Three ‘shelves / scroll-like’ bony protuberances from each wall; nasal conchae (sometimes called turbinates)

Groove inferior to each called nasal meatus

Mucous covered

Increase surface area and cause air turbulence meaning particles more likely to become trapped in mucous

Also extract moisture and heat on exhaling so not lost

Question 9

Paranasal sinuses

Answer 9

Extensions of nasal cavity; drain into lateral walls
Develop in adolescence

Four pairs named after bone in which they are found:
Ethmoid air cells
Sphenoid sinuses
Maxillary sinuses (largest)
Frontal sinuses (variable in size)

Lined with respiratory mucosa
Help lighten skull and resonate voice
Naso-lacimal duct also drains into lateral wall of nasal cavity

Question 10

What is the Pharynx?

Answer 10

Funnel shaped tube between the nasal cavity (base of skull) and the oesophagus / larynx (C6)

Approximately 13cm long

Composed of skeletal muscle

Functions as:
Common pathway for food / air before splitting into the respiratory / digestive systems
Helps form sounds as a resonating chamber
Contains the tonsils as part of the immune system

Is subdivided into 3 regions:
Nasopharynx – at the level of the choanae in the nasal cavity

Oropharynx – at the level of the oral cavity and mouth

Laryngopharynx (or hypopharynx) – at the opening for the larynx: laryngeal inlet

Question 11

What is Nasopharynx?

Answer 11

Superior to soft palate; passage of air only

Swallowing elevates the soft palate to close the nasopharynx

Continuous with epithelial layer of respiratory region of nasal cavity; similar role

Pharyngeal tonsil on posterior wall; pathogens in air

Pharyngotympanic (Eustachian) tubes open into lateral wall

Adjacent ridge of tubular tonsils; prevent spread of infection into middle ear

Question 12

What is Orophraynx?

Answer 12

Continuous with nasopharynx above at the level of the soft palate; passage of air and food

Continues inferiorly to level of epiglottis / hyoid bone

Stratified squamous epithelium; protection

Opening with oral cavity called oropharyngeal (or fauces) isthmus

Closed when chewing; can still breath through nose

Surrounded by arches called palatoglossal folds

Inferior to this, anterior wall is formed by posterior (pharyngeal) part of tongue

More tonsils on posterior tongue (lingual) and lateral walls of oropharynx (palatine)

Question 13

What is Laryngophalynx?

Answer 13

Continuous with oropharynx above at the level of the hyoid bone passage of air and food

Continues inferiorly to level of cricoid cartilage (C6) and start of oesophagus and larynx

Continuous with oesophagus
Stratified squamous epithelium; protection

Question 14

The Tonsils

Answer 14

They are collections of lymphoid tissue within the nasal and oral cavities and pharynx as part of the body’s defence against disease

The largest of these form distinct areas called tonsils

They form a ring around the pharynx and there are 4 main areas
Pharyngeal tonsil
Palatine tonsil
Lingual tonsil
Tubal tonsil

Question 15

What is Pharyngeal Musculature?

Answer 15

Arranged in two groups separated by fascia (allows passage of other structures)

Constrictors:
circular around cavity
Superior, middle, and inferior
Stacked like cups
Join posteriorly at pharyngeal raphe
Sequentially contract to propel food into oesophagus

Longitudinal:
Vertically orientated
Named according to origin;
Stylopharyngeus
Salpingopharyngeus
Palatopharyngeus
Insert on constrictors/fascia
Elevate pharynx during swallowing and pull wall over bolus to help propulsion

Question 16

What is the Larynx?

Answer 16

Main function of the larynx are
Breathing
Speaking making noise
Forced closure (val salva)
swallowing

5cm long between the laryngopharynx and trachea
Anterior to 4-6th cervical vertebrae

Suspended from hyoid bone superiorly

Inferiorly linked to trachea via ligaments

Is a framework of 9 cartilages supported and connected by fibrous membrane and intrinsic muscles

Innervated by branches of the vagus nerve

Mucosal lined

Start of the lower respiratory tract, functions as:
A sphincter to close off the lower respiratory tract; guide passage of food
Maintain a patent airway
To produce sound ‘Voice box’

Question 17

What is the Epiglottis?

Answer 17

Spoon/leaf-shaped elastic cartilage

Anchored anteriorly on thyroid cartilage

Projects postero-superiorly into the pharynx posterior to the tongue

Covered in mucosal epithelium containing tastebuds

Normally open at laryngeal inlet
On swallowing, larynx is elevated and epiglottis occludes trachea - like a trap door!

Question 18

So how do we swallow?

Answer 18

Aim to close off lower respiratory tract completely

Adduction of both vocal and vestibular folds
Rima glottides, vestibule, and vestibule closed

Extrinsic muscles elevate the larynx which causes the epiglottis to close the laryngeal inlet
Simultaneously causes the oesophagus, posteriorly, to open (attached to cricoid cartilage)

Question 19

The Neck

Answer 19

Extends from
Anteriorly
Inferior border of the mandible to the manubrium
Posteriorly
Posterior occipital protuberance to C7/T1 disc space

It is often divided into 4 compartments

Visceral;
Anterior
Contains parts of digestive and respiratory systems
Also contains several endocrine glands

Vertebral;
Posterior
Contains vertebrae and related muscles
Also contains spinal cord and nerves

Left / right Vascular;
Lateral
Contains major vessels and vagus nerve (CN X)

Separated by surrounding layers of cervical fascia

Question 20

Surface anatomy

Answer 20

C3 / C4:
Superior border of thyroid cartilage (palpable)
Bifurcation of common carotid artery

C5 / C6
Indentation of cricoid cartilage / first tracheal ring (palpable)
Inferior border of pharynx / larynx
Superior limit of trachea / oesophagus

Question 21

The Thyroid Gland

Answer 21

Lies anteriorly in the midline of the neck
There are 2 lobes and in total is approximately 5cm long.
It is part of the endocrine system and is key to several metabolic functions including:
Production of thyroxine, calcitonin and tri-idothyronine
Assists in protein, fat and carbohydrate production, heat production and calcium regulation

Question 22

Parathyroid glands

Answer 22

These are bilateral glands (4) in the posterior aspect of the thyroid gland

Secrete parathyroid hormones. This increases blood calcium levels.

Calcium is needed for
Muscle contraction
Transmission of nerve impulses
Blood clotting
Normal enzyme actions

Question 23

Acute sinusitis: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 23

Description
Acute inflammation of any of the paranasal sinus mucosa that lasts less than 4 weeks. If the nasal cavity is also involved its called rhinosinusitis

Causes
Normally follows an upper respiratory tract infection.

Symptoms
Fever, headache, postnasal discharge, abnormal sense of smell

Diagnosis
Plain film – nonspecific. On facial views you may see a gas fluid level in the maxillary sinus. Its really hard to see the ethmoid and sphenoid sinuses on these images.
CT – most common imaging method. Allows you to assess extension, causes and possible complications. Findings include, mucosal thickening, gas fluid levels in the sinuses, gas bubbles in the fluid.
MRI - T1 C+ (Gd) will show inflamed mucosa as this enhances while fluid doesn’t

Complications
Erosion through bone, orbital extension of the infection, intracranial extension – can lead to meningitis, subdural empyema and abscesses

Treatment
Antibiotics. If it becomes chronic, FESS (functional endoscopic sinus surgery) may be carried out.

Differential diagnosis
Air fluid level due to trauma
Chronic vs acute

Question 24

Cystic fibrosis: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 24

Description
Genetic disease affecting the lungs, liver, pancreas, small bowel and urogenital system

Causes
Most common genetic disease affecting 1:2000/3500 live births

Symptoms
Lung and upper respiratory system manifestations
Repeated bacterial infections, chronic sinusitis, nasal polyps

Diagnosis
Generally suspected due to genetic testing of parents or ultrasound findings at antenatal scans. Also tested post birth.

Complications
Life limiting
Increased risk of digestive system cancers, lymphoma, leukaemia

Treatment
For respiratory complications
Physiotherapy for airway clearance
Anti-inflammatory therapy
Antibiotics
Lung transplant

Differential diagnosis
No real differential due to availability of genetic testing.

Question 25

Nasal polyps: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 25

Description
Multiple benign polyps in the nasal cavity and paranasal sinuses

Causes
Most commonly seen in adults. Rare in children.
May be associated with cystic fibrosis, asthma, rhinosinusitis

Symptoms
Patient has a feeling of nasal obstruction, facial pain, headache, loss of smell. May also have symptoms of sinusitis

Diagnosis
CT is the preferred imaging method but MRI can also be used
You will see extensive mucosal polyps in the nasal cavity and/or sinuses. Usually hypodense.
May see associated bone erosion
May also see sinusitis signs

Complications
Impact on daily life for the patient

Treatment
Steroids.
Surgery if advanced

Differential diagnosis
Other causes of mucosal thickening such as nasopharyngeal cancer.
Foreign body

Question 26

Retropharyngeal abscess: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 26

Description
Life threatening infection involving the retropharyngeal space. Needs immediate diagnosis

Causes
Most commonly seen in young children (<5yrs)
Commonly a complication of a primary infection elsewhere in the sinuses, ear or nasopharynx.
These areas drain lymph to the retropharyngeal lymph nodes which become infected and develop into an abscess

Symptoms
Nonspecific symptoms of infection
May have stridor and neck swelling

Diagnosis
Ultrasound
Point of care has a use for screening.
You will see a complex collection.
Plain film
Useful as patient can be upright
Will see swelling posterior to the pharynx and widening or the paravertebral soft tissue
CT
Speedy – advantage as the patient’s airway may be compromised when laying down
Can assess any narrowing of the airway
It can be difficult to assess the amount of infection or mucosal swelling from CT
MRI
Much better at assessing infection extent
But takes longer and may be difficult for the patient

Complications
Infection can spread into the spine
Complete airway occlusion

Treatment
Surgical drainage
IV antibiotics
If treatment is timely nearly 100% of patient recover fully

Differential diagnosis
Other causes of a mass e.g. tumour

Question 27

Pharyngeal diverticulum: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 27

Description
Also known as a pharyngeal pouch
Posterior outpouching of the hypopharynx through a weakness in the muscle

Causes
Advancing age

Symptoms
Food and liquid become trapped leading to a sensation of trapped food, dysphagia, regurgitation, chronic cough, aspiration pneumonia

Diagnosis
Barium swallow is the ideal imaging method
You can see the diverticulum at the C5/6 level on the lateral view

Complications
Aspiration pneumonia

Treatment
Endoscopic surgery to resect it

Differential diagnosis
Other causes of patients symptoms

Question 28

Foreign bodies

Answer 28

In America foreign body aspiration is the 4th leading cause of death in younger children.

Upper airway compromise may present with choking and respiratory distress

More distal obstruction may present with mild wheezing, cough and shortness of breath

Once a foreign body is aspirated into the larynx or proximal trachea there is always the risk of respiratory compromise or further inhalation into the lungs

Most foreign bodies are organic – seeds, nuts etc.

Adults may present with ingestion of a bone – chicken / fish, dentures, hearing aid batteries etc.

Never underestimate what people will put in their mouths!

A lateral and AP soft tissue neck is the preferred imaging method to assess a foreign body in the upper airway.

Patient should be upright to stop any confusion with mucosal thickening

If the patient is unstable a lateral only may be performed

In children who a poor historians this may progress to a CXR and possibly a AXR

Important note – minimise patient and carer anxiety as carrying can exacerbate the patient’s respiratory distress

CT and MRI can be helpful for more accurate location and assessment of complications but are not the first line of imaging

Question 29

Tonsillitis and complications

Answer 29

Description
Inflammation of any of the tonsils

Causes
Bacterial infection, commonly Strep A

Symptoms
Pain, dysphagia, fever

Diagnosis
Imaging is not indicated unless there is concern for complications such as an abscess
CT and MRI will show tonsillar enlargement and if there is an abscess will show a fluid collection

Complications
Peritonsillar abscess (quinsy)

Treatment
Antibiotics. Oral if uncomplicated, IV if there is concern for quinsy

Differential diagnosis
Other causes of mucosal thickening such as lymphoma

Question 30

Underactive thyroid- Hypothyroidism: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 30

Description
The thyroid does not produce enough thyroid hormone resulting in decreased cellular metabolism.

Causes
Autoimmune diseases such as Hashimoto’s is the most common cause.

Symptoms
Affects nearly every system in the body
SOB
Muscle / joint pain
Weight gain, cold intolerance

Diagnosis
US is the standard imaging method.
Will see an abnormal size of the thyroid gland
An alteration in the thyroid texture and abnormal colour flow patterns

Complications
Depends on body system most affected but can lead to heart arrythmias

Treatment
Drugs to replace the thyroid hormone – levothyroxine

Differential diagnosis
Vast!

Question 31

overactive thyroid- Hyperthyroidism: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 31

Description
The thyroid produces too much thyroid hormone

Causes
Graves disease, radiation or drug induced, tumours

Symptoms
Heart arrythmias most commonly
Goitre
Weight loss

Diagnosis
Generally a blood test
Nuclear medicine thyroid scan to check for cause

Complications
Eye problems such as double vision, pregnancy complications

Treatment
Drugs, radioactive iodine treatment, surgery

Differential diagnosis

Question 32

Thyroid cancer: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis

Answer 32

Description
As the name suggests!

Causes
Head and neck radiotherapy
Family history
There are many different types

Symptoms
Usually a palpable mass

Diagnosis
US – seen as a mass with an irregular outline
Often needs a US fine needle aspiration to get a sample
CT is best for staging and to check lymph nodes
MRI has a slightly higher sensitivity than CT

Complications
Patients may be at risk of cancers elsewhere

Treatment
Surgery and radioactive iodine treatment

Differential diagnosis
Abscess or other reason for a mass11

Question 33

Enlarged lymph nodes: description, Causes, Symptoms, Diagnosis

Answer 33

Description
Enlarged lymph nodes

Causes
Infection
Neoplastic (due to cancer)
Due to certain drugs

Symptoms
Depends in cause but can cause pain and difficulty in movement

Diagnosis
Can be seen and measured on CT and MRI.
PET will show intense F-FDG uptake