Anatomy of Respiratory Tract Flashcards
What is included in the lower respiratory tract?
Trachea and below
What is included in the upper respiratory tract?
The respiratory system lying outside the thorax
Includes nasal cavity, pharynx and larynx
Functions of the nasal cavity?
Warms and humidifies air
Traps particulate matter and pathogens
Smell
Drains and clears paranasal sinuses and lacrimal ducts
Name the three regions of the nasal cavity and where are they?
Vestibule - area surrounding external opening to nasal cavity
Olfactory region - located at apex of nasal cavity
Respiratory region - further back?
What are the olfactory and respiratory regions lined with?
Olfactory - olfactory cells and olfactory receptors
Respiratory region - ciliated pseudostratified epithelium and mucus-secreting goblet cells
Function of conchae?
Create pathways for air to flow
Increase SA of nasal cavity
Make airflow turbulent and slower
What is the pharynx?
A muscular tube connecting the nasal cavities to larynx and oesophagus
Name the three parts of the pharynx and their epithelium
Nasopharynx - pseudostratified columnar
Oropharynx - stratified squamous
Laryngopharynx - stratified squamous
What connects the nasopharynx and the middle ear cavity? What does it allow?
Eustachian tube
Allows pressure in the middle ear cavity to be equalised to atmospheric pressure
What is contained in the non-olfactory region of the pharynx?
Mucous glands venous sinuses in the lamina propria.
What happens in the non-olfactory region?
Venous plexuses swell every 20-30 mins to alternate airflow - prevents one side from over-drying
Arterial flow warms air
What is in the olfactory region?
Olfactory cells and Bowman’s glands.
No goblet cells and therefore no mucus
What are Bowman’s glands?
Serous glands which flush odourants from epithelial surfaces
What two structures is the larynx between?
Links the pharynx and trachea
What is the cartilaginous skeleton of the larynx made up of?
Epiglottis
Thyroid cartilage
Cricoid cartilage
Paired arytenoid cartilage
What is the cartilage skeleton of the larynx linked together by?
Ligaments and muscle
What is the glottis?
The vocal cords together with the aperture between them
When are the cords abducted?
Respiration
When are the cords partially abducted?
During speech (phonation)
When are the cords adducted?
Swallowing to prevent inhalation of food
Initial part of cough reflex - involuntary
During straining - voluntary
What causes the movement of the vocal cords?
The laryngeal muscles
What do the extrinsic and intrinsic laryngeal muscles move?
Extrinsic - entire larynx
Intrinsic - actual vocal cords
Which nerve supplies the laryngeal muscles?
The recurrent laryngeal nerve
Clinical relevance of the recurrent laryngeal nerves?
Left nerve has a long course, part of which is inside the thoracic cavity.
If there is intrathoracic disease, can compress the nerve and cause a hoarse voice - get paralysis of the left vocal cord.
What mechanisms are there to prevent aspiration of food/liquid?
Abduction of the vocal cords
Epiglottis which folds down to cover laryngeal inlet
Name the four paranasal sinuses
Frontal
Ethmoidal cells
Sphenoidal cells
Maxillary
Which sinuses don’t develop until 2 years of age?
Ethmoidal cells
What epithelium are the sinuses lined by?
Pseudostratified columnar ciliated
What is the name of the point where the trachea divides? What vertebral level is this at?
Carina
T4/5
What bridges the gap in the C shaped cartilage of the trachea?
Posterior tracheal is muscle
Differences between right and left bronchial trees?
Right is shorter, wider and more vertical
Left is more horizontal
If an object was to be aspirated, which bronchus would it most likely go down?
The right
How many lobar bronchi are there?
3 on right (upper, middle and lower)
2 on left (upper and lower)
What does a segmental bronchus supply?
A broncho-pulmonary segment (pyramid shape)
Also supplied by a pulmonary artery and vein
Clinical importance of segments?
A segment can be removed surgically with little damage to others
What are the lobes of the lungs called?
Right - upper/superior, middle and lower/inferior
Left - upper and lower
What is the lingula?
An area of the left upper lobe which corresponds to the right middle lobe
What are the names of the surfaces of the lungs?
There are three
- mediastinal
- diaphragmatic
- costal
Clinal significance of the apex of the lung extending into the neck?
Apical lung tumours can involve structures in the root of the neck eg brachial plexus
Subclavian vein cannulation can cause a pneumothorax
What is the hilum?
Where the pulmonary vessels, nerves and lymphatics enter and exit the lung
What do the lymphatics of the lung drain into?
Hilar lymph nodes
What are the two blood supplies to the lungs and where do they transport to and from?
Bronchial arteries - from aorta to supply the bronchial tree and bronchioles with oxygenated blood
Pulmonary arteries - deoxygenated blood from right heart to alveoli. Also supply the alveoli
What are the compartments of the mediastinum?
Superior
Middle
Posterior
Anterior
Ww here is the superior mediastinum situated?
Between the sternal angle and the thoracic aperture
Contents of the anterior mediastinum
Loose connective tissue Fat Lymphatic vessels Lymph nodes Branches of internal thoracic vessels
