Anatomy and pattern recognition of the upper respiratory system and neckNormal and abnormal Flashcards
Revision of the respiratory system
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
Respiratory system: devisions
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
Nose: description
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
External nose
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
Nasal cavity
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
Nasal cavity: regions
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
Nasal cavity: Respiratory epithelium
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
Nasal cavity – lateral walls
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
Paranasal sinuses
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
What is the Pharynx?
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
What is Nasopharynx?
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
What is Orophraynx?
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)
What is Laryngophalynx?
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
The Tonsils
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
What is Pharyngeal Musculature?
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
What is the Larynx?
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’
What is the Epiglottis?
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!
So how do we swallow?
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)
The Neck
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
Surface anatomy
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
The Thyroid Gland
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
Parathyroid glands
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
Acute sinusitis: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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
Cystic fibrosis: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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.
Nasal polyps: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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
Retropharyngeal abscess: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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
Pharyngeal diverticulum: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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
Foreign bodies
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
Tonsillitis and complications
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
Underactive thyroid- Hypothyroidism: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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!
overactive thyroid- Hyperthyroidism: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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
Thyroid cancer: description, Causes, Symptoms, Diagnosis, Complications, Treatment, Differential diagnosis
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
Enlarged lymph nodes: description, Causes, Symptoms, Diagnosis
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
