Resp anatomy Flashcards
What are the peripheral attachments of the diaphragm?
Lumbar vertebrae and arcuate ligaments.
Costal cartilages of ribs 7-10 (attach directly to ribs 11-12).
Xiphoid process of the sternum.
Where does the right crus arise from?
L1-L3 and their intervertebral discs
Where does the left curs arise from?
L1-L2 and their intervertebral discs
Which dome of the diaphragm (left or right) lies slightly higher and why?
The right due to the presence of the liver
What are the three openings that act as conduit in the diaphragm?
Caval hiatus (T8) Oesophageal Hiatus (T10) Aortic Hiatus (T12)
What passes through the caval Hiatus?
inferior vena cava
Terminal branches of the right phrenic nerve
What passes through the oesophageal hiatus?
Oesophagus
Right and left vagus nerves
Oesophageal branches of left gastric artery/vein
What passes through the aortic hiatus?
Aorta
Thoracic duct
Azygous vein
What is the motor innervation of the diaphragm?
The left half by the left phrenic nerve and right half by the right phrenic nerve
What is the root of the phrenic nerve?
Formed in the neck within the cervical plexus, containing fibres from C3-C5
What is the arterial supply to the diaphragm?
The inferior phrenic arteries which arise directly from the abdominal aorta. Minor supply from the superior phrenic, pericardiacophrenic, and musculophrenic arteries.
How can a lesion of the phrenic nerve occur?
Mechanical trauma
Compression
Myopathies
Neuropathies
What are the symptoms of a paralysis of both sides of the diaphragm?
Poor exercise tolerance, orthopnoea and fatigue
In adolescence, what is the role of the thymus gland?
Development of the immune system
What is the embryological derivative of the thymus gland?
The third pharyngeal pouch
What is the shape of the thymus gland?
An asymmetrical, flat shape with a lobular structure
Describe the cortical portion of the thymus
Located peripherally within each follicle. It is largely composed of lymphocytes, supported epithelial reticular cells.
Describe the medullary portion of the thymus
Located centrally within each follicle. It contains fewer lymphocytes than the cortex, and an increased number of epithelial cells. Hassall’s corpuscles are also present – these are concentric arrangements of epithelial reticular cells. Their function is unclear.
Where is the thymus located?
Within the thoracic superior mediastinum, posterior to the manubrium of the sternum. In some individuals, it can extend superiorly into the neck, and inferiorly into the anterior mediastinum
What is the arterial supply to the thymus?
The anterior intercostal arteries and small branches of the internal thoracic arteries
What is the venous supply from the thymus?
The left brachiocephalic and internal thoracic veins
What is DiGeorge syndrome?
A genetic syndrome caused by the deletion of part of chromosome 22
What are the common features of DiGeorge syndrome?
Congenital heart defects Abnormal facies Thymic aplasia Cleft palate Hypoparathyroidism
What are the two regions of the breast?
Circular body- Largest and most prominent part of the breast
Axillary tail- Smaller part, runs along the inferior lateral edge of the pectoralis major towards the axillary fossa
What is the pigmented area of skin surounding the nipple?
Areolae
What are mammary glands?
Modified sweat glands consisting of a series of ducts and secretory lobules. Each lobule consists of many alveoli drained by a single lactiferous duct. These ducts converge at the nipple.
What are the roles of the ligaments formed by the fibrous stroma surounding the mammary glands?
Attach and secure the breast to the dermis and underlying pectoral fascia
Seperate the secretory lobules of the breast
What is the retromammary space?
A layer of loose connective tissue between the breast and pectoral fascia
What is the arterial supply to the medial aspect of the breast?
The internal thoracic artery- a branch of the subclavian artery
What vessels supply blood to the lateral part of the breast?
Lateral thoracic and thoracoacromial branches
Lateral mammary branches
Mammary branch
What do the lateral thoracic and thoracoacromial branches originate from?
The axillary artery
What does the lateral mammary branches originate from?
The posterior intercostal arteries (derived from the aorta)
What does the mammary branch originate from?
The anterior intercostal artery
What are the groups of lymph nodes that receive lymph from breast tissue?
Axillary nodes (75%) Parasternal nodes (20%) Posterior intercostal nodes (5%)
What is the lymphatic drainage of the skin of the breast?
Drains into the axillary, inferior deep cervical and infraclavicular nodes
What is the lymphatic drainage of the nipple and areola?
The subareolar lymphatic plexus
What sensory and autonomic is the innervation of the breast?
Anterior and lateral cutaneous branches of the 4th to 6th intercostal nerves
What regulates the secretion of milk from the breast?
Prolactin
Which lung is bigger than the other lung and why?
The right lung is bigger than the left due to the presence of the heart
How many lobes are there in the right lung?
3
How many lobes are there in the left lung?
2
What are the lobes of the right lung?
Superior, middle and inferior
What are the fissures of the right lobe?
Oblique fissue and horizontal fissure
Where is the right lung’s oblique fissure?
Runs from the inferior border of the lung in a superoposterior direction, until it meets the posterior lung border
Where is the right lung’s horizontal fissure?
Running horizontally from the sternum at the level of the 4th rib, to meet the oblique fissure
What are the lobes of the left lung?
Superior and inferior
What is the division of the superior and inferior lobe of the left lung?
The oblique fissure
What are the three surfaces of the lungs?
The mediastinal surfaces
The diaphragmatic surface
The costal surface
Where are the lung hilums located?
On the mediastinal surfaces of each lung
Where is the cardiac notch of the lung?
On the left lung, on the anterior border. It is a deep notch created by the apex of the heart.
What structures are contained within a lung root?
A bronchus, pulmonary artery, two pulmonary veins, bronchial vessels, pulmonary plexus of nerves and lymphatic vessels
Which bronchus has a higher incidence of foreign body inhalation and why?
The right bronchus due to its wider shape and more vertical course
What is the order of divisions of the trachea in order?
Trachea Bronchus Lobar bronchi Segmental bronchi Conducting bronchioles Terminal bronchioles Respiratory bronchioles Alveoli
What vessels supply the bronchi, lung roots, pleura and supporting lung tissue with extra nutritive blood supply?
The bronchial arteries, which arise from the descending aorta
Which vein does the right bronchial vein drain into?
The azygos vein
Which vein does the left bronchial vein drain into?
The accessory hemiazygos vein
What is the parasympathetic supply to the lungs?
Vagus nerve from the pulmonary plexuses
What is the parasympathetic role of the vagus nerve in the lungs?
Stimulate secretion from the bronchial glands, contraction of the bronchial smooth muscle, and vasodilation of the pulmonary vessels
What is the sympathetic supply to the lungs?
The pulmonary plexus which is derived from the sympathetic trunks
What is the sympathetic role of the sympathetic trunks in the lungs?
Stimulate relaxation of the bronchial smooth muscle, and vasoconstriction of the pulmonary vessels
What is the roles of the visceral afferent fibres of the pulmonary plexuses in the lung?
Conduct pain impulses to the sensory ganglion of the vagus nerve
What is the level of the carina?
The sternal angle- T4/5
How is the trachea held open?
C-shaped rings of cartilage. The free ends of the rings are supported by the trachealis muscle
What is the histology of the trachea?
Ciliated, pseudostratified columnar epithelium, interspersed by goblet cells.
What is involved in the mucociliary escalator?
Sweeping movements by the cilia and the mucus from goblet cells
What is the sensory innervation of the trachea?
The recurrent laryngeal nerve
What is the arterial supply of the trachea?
The tracheal branches of the inferior thyroid artery
What is the venous drainage of the trachea?
Brachiocephallic, azygos and accessory hemiazygos veins
What is the innervation of the bronchi?
The vagus nerve
What is the arterial supply of the bronchi?
Branches of the bronchial arteries
What is the venous drainage of the bronchi?
Bronchial veins
What is the role of club cells?
Produce a surfactant lipoprotein in the bronchioles which is instrumental in preventing the walls of the small airways sticking together during expiration
What is asthma?
A chronic inflammatory disorder of the airways, characterised by hypersensitivity, reversible outflow obstruction and bronchospasm
What are the two parts of the lung pleura?
Visceral pleura (covering the lung) Parietal pleura (covering the internal surface of the thoracic cavity)
Which type of lung pleura (visceral or parietal) is thicker?
Parietal
What is the pleural cavity?
The potential space between the parietal and visceral pleura. It contains a small volume of serous fluid.
What are the two major functions of the serous fluid in the pleural cavity?
It lubricates the surfaces of the pleurae, allowing them to slide over each other. The serous fluid also produces a surface tension, pulling the parietal and visceral pleura together. This ensures that when the thorax expands, the lung also expands, filling with air.
What are the two recesses present in each pleural cavity?
Costodiaphragmatic
Costomediastinal
Where is the costodiaphragmatic recess?
Between the costal pleurae and diaphragmatic pleura
Where is the costomediastinal recess?
Between the costal pleurae and the mediastinal pleurae, behind the sternum
What is the innervation to the parietal pleura?
The phrenic and intercostal nerves
What is the blood supply to the parietal pleura?
The intercostal arteries
What is the parietal pleura sensitive to?
Pressure, pain and temperature
What do the sensory fibres of the visceral pleura detect?
Stretch only
What is the innervation of the visceral pleura?
The pulmonary plexus
What is the arterial supply to the visceral pleura?
The bronchial arteries (branches of the descending aorta)
How does a pneumothorax occur?
When air or gas is present within the pleural space
What are the clinical features of a pneumothorax?
Chest pain, shortness of breath and asymmetrical chest expansion.
What are the two main classes of pneumothorax?
Spontaneous and traumatic
When does a spontaneous pneumothorax occur?
A spontaneous pneumothorax occurs without a specific cause. It is sub-divided into primary (no underlying respiratory disease) and secondary (underlying respiratory disease present).
When does a traumatic pneumothorax occur?
A traumatic pneumothorax occurs as a result of blunt or penetrating chest trauma, such as a rib fracture (often seen in road traffic collisions).
What are the treatments for pneumothorax?
Treatment depends on identifying the underlying cause. Primary pneumothoraces tend to be small and generally require minimal intervention, whereas secondary and traumatic pneumothoraces may require decompression to remove the extra air/gas in order for the lung to reinflate (this is achieved via the insertion of a chest drain).
