Lower Respiratory Tract Anatomy

Thoracic wall arterial supply:

Posterior intercostal arteries

Descending aorta

Anterior intercostal arteries

Internal thoracic artery

Importance of anastomoses?

Collateral circulation to get around blockage e.g. aortic coarctation

See widened costal margins on CXR (dilated intercostal arteries)

Thoracic wall venous drainage

Intercostal veins ultimately drain into:

Hemiazygous vein

Accessory hemiazygous vein

Azygous vein

Internal thoracic veins

Drain into:

Brachiocephalic vein (upper spaces)

SVC

Azygous vein

Intercostal veins

Hemiazygous vein

Accessory hemiazygous

vein

Tunstall & Shah 2012 Pocket Tutor: Surface Anatomy

2cc

6cc

6rib MCL8 rib MAL

Apex sits ~2cm above medial 1/3 of clavicle

Horizontal fissure:4thcc horizontally back to oblique fissure

Oblique Fissure: T3 Spinous Process to 6th cc anteriorly

Lung Surface Markings

Tunstall & Shah 2012 Pocket Tutor: Surface Anatomy

8 rib MCL

10 rib MAL

6cc

Pleural Markings

Marks the point of reflection of parietal pleura from the thoracic wall.

Costodiaphragmatic recess = region between lung and pleura.

Liver biopsy…patient inhales or exhales?

Exhale! Extend the gap between the lungs + pleura.

Reduces risk of complications.

Trachea originates at what vertebral level?

C6 (continuation of cricoid cartilage)

Bifurcates at what vertebral level?

T4 / T5

More likely to aspirate into which bronchus? Why?

Right…more vertical, foreign body / gastric contents more likely to fall this way.

Why’re you worried about a flattened angle at the carina?

Lymph nodes inferior to carina…consider lung tumour!

What three things does the smallest functional unit of the lungs need (bronchopulmonary segments)?

Air supply.

Venous drainage.

Arterial supply.

Each segment is separated by fibrous tissue.

Pulmonary veins:

Run between segments.

Oxygenated blood.

Pulmonary artery:

Run with bronchi + bronchioles (need to for gas exchange)!

Deoxygenated blood.

Pulmonary vein

Pulmonary artery

Segmental 3° bronchus

Where does the diaphragm attach?

Diaphragm is a muscular & tendinous structure that domes into the thoracic cavity

What is the diaphragm?

The Diaphragm + External intercostals + Scalenes/ sternocleidomastoid

Tom Grant is 26 year old man with two lungs. What provides the driving force for inspiration when Tom is breathing?

Diaphragm attaches to costal margin & ribs 10-12 Diaphragmatic crura attach to

lumbar vertebrae

Central tendinous part for heart

A 35 year old man presents with dyspnoea that is worse on exertion and when lying down. His ECG is normal. He is a non-smoker, his lungs are clear and he has denies any recent trauma or accidents.

a) Angina b) hemi-diaphragmatic paresis c) Chest wall muscle straind) COPDe) Anaemia

The injury has cause him Atelectasis, what is Atelectasis?

- Incomplete expansion of the lungs- Diminishing volume affecting all or part of a lung - Obstructive/ non-obstructive/ postoperative- Obstructive due to obstruction of air flow between trachea and alveoli- Non-obstructive due to loss of contact between visceral and parietal pleura

What nerve supplies the diaphragm?

Diaphragm innervated by phrenic nerve (C3,4,5) for motor and sensoryAdditional sensory innervation on the periphery from intercostal nerves

Which one of these is normal? Why?

What three important structures pass through the diaphragm?

Vena cava thoracic-abdominal aorta oesophagus

Which vertebral level do they pass through the diaphragm?

Tunstall & Shah 2012 Pocket Tutor: Surface Anatomy

Vena Cava – T8

Oesophagus – T10

Descending Aorta – T12

Rosie is 75 year old obese ex-weightlifter with 3 children who experiences burning chest pain after meals. After being encouraged by her husband bob to visit her GP, the GP refers her for a CXR what might they find?

Hiatus herniaHerniation of stomach through the diaphragmatic oesophageal hiatus Mostly asymptomaticGORD most likely complicationMore likely in women who have given birth, obese people, increasing age

Bob prompting Rosie to visit the GP is called sanctioning and is one of the triggers to seek help known as the ‘lay referral’ system. What are 4 other triggers?

Interpersonal crisisSymptoms interfering with personal and/or social relationsInterference with work or physical activity A ‘temporalizing of symptomatology'

Gary Is in a car crash and experiences blunt trauma to this thorax, a decision is made to insert a chest drain. What is the most likely reason the chest drain is inserted in this instance?

Pneumothorax To give a passage for the air inside the pleural cavity to escape

What are additional indications for chest drain use?

HaemothoraxPleural effusionEmpyemaChylothorax (lymphatic effusion due to disruption/ obstruction of the thoracic duct)

Gary is rather spiritual and believes that his life force will be sucked out from his thorax by the chest tube. His spiritualism is one form of lay belief, name 4 others

Personal knowledge The media and the internetReligion Alternative and completmentary medicineFolk law Previous medical encounters

Triangle of safety

What are the surface markings for the triangle of safety

Where is a chest tube inserted?

Tunstall & Shah 2012 Pocket Tutor: Surface Anatomy

Posterior axillary line Anterior axillary line

Nipple line 3RD OR 4TH ICS

LATERAL BORDER OF PEC. MAJOR

ANTERIOR BORDER OF LAT DORSI

NOT ALWAYS ACCURATE

How many lobes do the lungs have?

Right lung has 3 lobes and the left has 2 lobes....although this can vary

What is the left lobes middle lobe called?

Lingual lobe

Gary lost his right middle lobe post-pneumothorax. Now identifying as disabled he became an activist for equality and learned the UK equality act, what does the UK equality act state?

The clinical education fellows at Warwick hospital struck up strong relationships with Gary as they used his lack of a right middle lobe to test auscultation technique on the students. What are the auscultation points of the chest that ensure all lobes are auscultated?

Upper lobes – front of chest – large region to choose from (2/3 ICS)

Right middle lobe – axillary region – 4th ICS

Lower lobes – posteriorly - large region to choose from