Respiratory: Lecture 7 - What are the Anatomical-Pathological Consequences of Chronic Cough? Flashcards
Why do you cough?
Protect and clear our respiratory tract (“airways”)
What is the purpose of the Cough Reflex?
- Protects the lungs against aspiration (the inhalation of foreign bodies)
- Enhances clearance of the excess mucus produced by inflamed respiratory mucosa
What stimulates the sensory receptors in the mucosa of the respiratory tree?
- Inflammatory mediators (produced e.g. secondary to infections/asthma)
- Irritant chemicals (e.g. in cigarette smoke, pollution)
- A build up of mucus (e.g. in asthma/infection)
- Certain drugs (cough can be an unpleasant side-effect of a drug)
In Upright patients were will foreign bodies tend to be inhaled to?
The Inferior Lobe
What does dynamic airway compression in asthma cause?
- expiration difficult
- build up of air trapped in alveoli can lead to rupture of lung & visceral pleura
Describe the bifarcation of the lung ?
What does a breach of the visceral pleura cause?
- Causes the vaccum to be lost.
- The lung recoils towards the lung root due to elastic recoil
- Results in a small pneumothorax
What is considered a small Pneumothorax?
Less than 2 cm between the lung and the parietal pleura
What is considered a large pneumothorax?
Greater than 2 cm between the lung and the parietal pleura
How is a Pneumothorax diagnosed?
1.History:
•as per clinical lectures
2.Examination:
- reduced ipsilateral chest expansion
- reduced ipsilateral breath sounds
- hyper-resonance on percussion
3.Investigation (CXR):
- absent lung markings peripherally
- lung edge visible (red arrows)
What is a tension Pneumothroax?
A pneumothorax were the mediastinal strucutre have shifted due to a build up of pressure in the pleural cavity.
What is the anatomy of the mediastinum?
- Superior section of mediastinum is from T4 superiorly. (This is the level of the sternal angle)
- The heart is in the middle of the mediastinum
- The Anterior Mediastinum is infront of the heart - The Thymus is here
- The Posterior mediastinum is behind the heart - the great vessels of the heart, the esophagus, the trachea, the phrenic nerve, the cardiac nerve, the thoracic duct, thethymus, and the lymph nodes of the central chest occupy this space
What is found in the posterior mediastinum?
- The great vessels of the heart,
- the esophagus,
- the trachea,
- the phrenic nerve,
- the cardiac nerve,
- the thoracic duct
- thethymus,
- the lymph nodes of the central chest.
What are the consequences of mediastinal shift?
- SVC compression reduces venous return to the heart leading to hypotension (low arterial blood pressure)
- tension pneumothorax may be bilateral!!
How is a large Peumothorax managed?
What causes a tension Pneumothorax?
- the torn pleura can create a one-way valve that permits air to enter the pleural cavity on each inspiration but prevents air escaping again on expiration
- with each inspiration more air enters the pleural cavity
- the pneumothorax expands & the lung collapses towards its root
- eventually the build up of air in the pleural cavity applies tension (pressure) to the mediastinal structures
How is a large Pneumothorax treated?
- needle aspiration (thoracentesis)
- the siting of a chest drain
-both procedures via the:
4th or 5th intercostal space in the midaxillary line
What is the “Safe Triangle”?
- the anterior border of latissimus dorsi
- the posterior border pectoralis major
- axial line superior to the nipple
what is the emergency management of a tension pneumothorax?
insert a large gauge cannula (grey/orange) into the pleural cavity via the 2nd or 3rd intercostal space in the midclavicular line on the side of the tension Pneumothorax
What can be done by thoracoscopy in (recurrent) pneumothorax?
VATS = Video Assisted Thorascopic Surgery
- endoscopic examination of the pleural cavity
- access via an intercostal space in the safe triangle
- suturing/stapling of pleural perforations
- pleural biopsy
- pleurectomy
- chemical pleurodesis:
magnesium silicate (talc) slurry introduced into pleural cavity to produce adhesion between the parietal and visceral Pleurae
What is a Hernia(e) ?
Any structure passing through another, so ending up in the wrong place
What are common Herniae?
- Diaphragmatic Hernia
- Umbilical Hernia
- Inguinal Hernia
- Fermoral Hernia
What is a Hernia caused by a surgery called?
Incisional Hernia
What does Hernia cause - in terms of pressure?
Can cause an increase in pressure on one side of that part of the wall.
May cause Chronic cough due to repeated bouts of increased intra-abdominal pressure on the diaphragm & the anterolateral abdominal (including the inguinal region/femoral triangle)
Where do Diaphragmatic Herniae develop?
- normal anatomical weaknesses at the attachments to the xiphoid
- normal anatomical weaknesses at posterior attachments
- oesophageal hiatus (hiatus herniae are common)
What Hernia is depicted?
Paraoesophageal Hiatus Hernia
The herniated part of the stomach passes through the oesophageal hiatus to become parallel to the oesophagus & in the chest
What Hernia is depicted?
Sliding Hiatus Hernia
The herniated part of the stomach slides through the oesophageal hiatus into the chest with the gastro-oesophageal junction
What weakness causes an Inguinal Hernia?
The weakness in inguinal herniae is the presence of the inguinal canal in the inguinal part of the anterolateral abdominal wall
What causes the increase in pressure to cause an Inguinal Hernia?
- chronic cough
- chronic constipation
- occupational lifting of heavy weights
- athletic effort
What is depicted in the image?
- The Anterior Superior Iliac Spine
- Pubic Tubercle
Where does the ASIS and the Pubic Tubercle ligaments attach?
Attach between thr ASIS and the Pubic Tubercle
What are the Inguinal ligaments an inferior border of?
The External Oblique Aponeuroses
What does medial halves of the Inguinal Ligaments form the floors of?
Inguinal Canals.
What is displayed on this diagram (on the left) ?
What are the Inguinal Canals?
- ~ 4 cm long passageways through the anterior abdominal wall in the inguinal regions
- each canal runs between a deep ring (the entrance to the canal) and a superficial ring (the exit from the canal)
What are the layers of the anterolateral abdominal wall in the Inguinal region?
Superiolaterally
- Visceral Peritoneum
- Parietal Peritoneum
- Transversalis Fascia
- Transversus abdominis
- Interal Oblique
- Inguinal Liagment
- Deep Fascia
- Superfical Fascia of Scrotum
What is contained in the spermatic cord?
- Vas Deferens
- Testicular Artery
- Pampiniform Plexus
Describe the stages of testicle moving through the layers of the anterolateral abdominal wall in the inguinal region?
The Processus vaginalis is an outpouching parietal peritoneum which is used to guide the testicle
Testical moves through the transversalis fascia - This forms the Internal spermatic fascia of the testicle
Testicles moves through the skeletal muscle fibres from the internal oblique - Forms the cremasteric fascia
Testicles moves through the V shaped efect in the medial end of the external oblique apoeurosis
Testicle moves through the external oblique aponeurosis - forms the external spermatic fascia
What does the covering of the transversalis fascia form on the Testicle?
The Internal Spermatic Fascia
What does the covering of skeletal muscle fibres on the testicle form on the testicle?
The Cremasteric Fascia
What does te covering of external oblique aponeurosis form on the testicle?
The External Spermatic Fascia
What is the Tunica Vaginalis?
The remains of the Processus Vaginalis
What are the openins of the inguinal canal?
The Deep ring of the Inginal Canal
The Superficial ring of the Inguinal Canal
What muscles does the Conjoint Tendon anchor to the Pubic Bone?
- Transverus Abdominis
- Internal Oblique
- External Onlique
How many coverings does the spermatic cord have?
Three
What drains deoxygenated blood from the testis?
The Pampiniform Venous Plexus
What supplies the testes with oxygenated blood?
The Testicular Artery
What transports sperm?
The Vas Deferens.
