Thoracic I

Question 1

You are auscultating the heart of a 68-year-old patient who has presented with chest pain. Your stethoscope is placed in the second intercostal space on the right sternal edge.

Answer 1

Aortic valve
The best sites for heart valve auscultation are:

Aortic valve: the second intercostal space on the right sternal edge.
Pulmonary valve: the third costal cartilage on the left sternal edge.
Mitral valve: at the apex of the left ventricle or the site of the apex beat in the fifth intercostal space in the mid-clavicular line.
Tricuspid valve: the fifth intercostal space on the right sternal edge.

Question 2

You are auscultating the heart of a 50-year-old patient who has presented with shortness of breath. Your stethoscope is placed over the apex of the heart.

Answer 2

Mitral valve
The best sites for heart valve auscultation are:

Aortic valve: the second intercostal space on the right sternal edge.
Pulmonary valve: the third costal cartilage on the left sternal edge.
Mitral valve: at the apex of the left ventricle or the site of the apex beat in the fifth intercostal space in the mid-clavicular line.
Tricuspid valve: the fifth intercostal space on the right sternal edge.

Question 3

You are auscultating the chest of a 63-year-old lady in a pre-operative clinic. Your stethoscope is placed in the fifth intercostal space on the right sternal edge.

Answer 3

Tricuspid valve
The best sites for heart valve auscultation are:

Aortic valve: the second intercostal space on the right sternal edge.
Pulmonary valve: the third costal cartilage on the left sternal edge.
Mitral valve: at the apex of the left ventricle or the site of the apex beat in the fifth intercostal space in the mid-clavicular line.
Tricuspid valve: the fifth intercostal space on the right sternal edge.

Question 4

In the case of a patient sitting upright with his arms by his side, a line drawn between the tips of the scapulae will correspond to the vertebral body of which of the following?
(Please select 1 option)
	 T6
	 T7
	 T8
	 T9
	 T10

Answer 4

T7

A line drawn between the tips of the scapulae corresponds to the vertebral body of T7.

A line drawn between the superior margin of the iliac crests is level with the vertebral body of L4.

Question 5

In the right lung, the number of bronchopulmonary segments is which of the following?
(Please select 1 option)
	 7
	 8
	 9
	 10
	 11

Answer 5

10

There are 10 bronchopulmonary segments in the right lung.

These are:

Upper lobe:

Apical
Posterior
Anterior
Middle Lobe:

Medial
Lateral
Lower Lobe:

Superior ('apical')
Anterior basal
Posterior basal
Medial basal
Lateral basal.

Question 6

A 72-year-old male attends the emergency department with severe upper abdominal pain.
He also complains of shoulder tip pain and you think he has a perforated duodenal ulcer.
The shoulder pain is explained by irritation of the diaphragmatic peritoneum referred to which dermatome?
(Please select 1 option)
C2 dermatome
C3 dermatome
C4 dermatome
C5 dermatome
C6 dermatome

Answer 6

C4

Irritation of the diaphragm is usually referred to the C4 dermatome which supplies the shoulder regions.

Question 7

Regarding the diaphragm, which of the following is correct?
(Please select 1 option)
Has accessory motor innervation from the intercostal nerves
Has an origin from the body of the sternum
Has the aorta passing behind it at T10
Has the left phrenic nerve passing through its central tendon
Is partly derived from the pleuroperitoneal membranes

Answer 7

Is partly derived from the pleuroperitoneal membranes This is the correct answerThis is the correct answer
The diaphragm is partly derived from the pleuroperitoneal membranes and mesoderm, innervation is from C345 via the phrenic nerve. It consists of a central tendon and a muscular margin.

The fleshy fibres rise in front from the back of the xiphoid cartilage of the sternum, laterally by six serrations from the inner surfaces of the lower six ribs interdigitating with the transversalis, posteriorly from the arcuate ligaments, of which there are five, a pair of external, a pair of internal, and a single median one.

The external arcuate ligament stretches from the tip of the twelfth rib to the costal process of the first lumbar vertebra in front of the quadratus lumborum muscle, the internal and middle are continuations of the crura which rise from the ventro-lateral aspects of the bodies of the lumbar vertebrae, the right coming from three, the left from two.

On reaching the level of the twelfth thoracic vertebra each crus spreads out into a fan-shaped mass of fibres, of which the innermost join their fellows from the opposite crus in front of the aortic opening to form the middle arcuale ligament; the outer ones arch in front of the psoas muscle to the tip of the costal process of the first lumbar vertebra to form the internal arcuate ligament, while the intermediate ones pass to the central tendon.

The aorta crosses the diaphragm at T12.

Question 8

Which of the following is correct of the left main bronchus?
(Please select 1 option)
Contains complete cartilagenous rings
Divides into 3 secondary bronchi
Divides into 10 tertiary bronchi
Is shorter than the right bronchus
Runs more vertically than the right bronchus

Answer 8

Divides into 10 tertiary bronchi

The left bronchus is narrower and less vertical than the right, is nearly 5 cm long and once entered the hilum divides into a superior and inferior lobar bronchus.

The right bronchus is 2.5 cm long and gives off three branches to the three lobes of the right lung.

Both lungs have 10 tertiary (segmental) bronchi.

The trachea and extra pulmonary bronchi have a framework of incomplete ‘rings’ of hyaline cartilage, united by fibrous tissue and smooth muscle.

Question 9

Which of the following numbers of segments is contained in the left lung?
(Please select 1 option)
	 12
	 11
	 10
	 8
	 5

Answer 9

10

The lungs are divided first into right and left, the left being smaller to accommodate the heart.

The lungs are further subdivided into lobes (three on the right, two on the left) by the oblique and horizontal fissures on the right and only the oblique fissure on the left.

Each lobe of the lung is further divided into pyramidal bronchopulmonary segments. Bronchopulmonary segments have the apex of the pyramid in the hilum whence they receive a tertiary bronchus, and appropriate blood vessels.

There are 10 segments of the right lung and typically 10 on the left although on the left it is not uncommon for one or more segmental bronchi to share a common stem.

Question 10

A smooth flat area of bone usually covered with cartilage, where a bone, such as a rib, articulates with another.

Answer 10

Facet
Facets, such as the superior and inferior facets on vertebrae, are flat and because they are covered in cartilage, help other bones to slide over them easily.

Question 11

The name given to a ridge on a bone.

Answer 11

Crest

A ridge of bone is known as a crest. There are ridges along the long bones of the arms and legs where muscles insert.

Question 12

The name given to a passage or tunnel through a bone.

Answer 12

Foramen

A channel in a bone is known as a foramen

Question 13

The name given to parts of a bone which are projecting and/or spike-like.

Answer 13

Process

Projections are known as processes. An example includes the styloid processes.

Question 14

The name given to small raised eminences on bones.

Answer 14

Tubercle

Small raised eminences on bones are known as tubercles. These are different from trochanters as they are much larger.

Question 15

You are examining a patient with left sided weakness and test reflex knee extension.

Answer 15

L3/L4

Limb reflexes:

Biceps	C5/C6
Triceps	C7/C8
Supinator	C5/C6
Knee	L3/L4
Ankle	S1/S2

Question 16

A knife stabbed horizontally through the fourth intercostal space to the right of the sternum is most likely to damage which of the following?
(Please select 1 option)
	 Descending aorta
	 Hemiazygos vein
	 Right brachiocephalic vein
	 Right pulmonary artery
	 Thoracic duct

Answer 16

Right pulmonary artery

The hemiazygos vein, descending aorta and thoracic duct are found on the left.

The right brachiocephalic vein is formed behind the sternoclavicular joints by the union of the internal jugular and subclavian veins.

The left and right brachiocephalic veins join at the middle of the right border of the manubrium to form the superior vena cava.

The superior vena cava enters the right atrium at the level of the right third costal cartilage.

Question 17

Which of the following is true regarding the superior mediastinum?
(Please select 1 option)
Contains the right recurrent laryngeal nerve
Has the heart and the pericardium as its contents
Has the mediastinal pleura laterally
Is bounded by the bodies of T3-T6 vertebrae posteriorly
Is traversed by the hemiazygos vein

Answer 17

Has the mediastinal pleura laterally

The superior mediastinum is the space between

The manubrium of the sternum anteriorly
The anterior surface of the bodies of T1-T4 vertebrae posteriorly
The plane of the thoracic inlet superiorly
The plane of the sternal angle inferiorly
The mediastinal pleura laterally.
The contents of the superior mediastinum include

Left brachiocephalic vein
Right brachiocephalic vein
Superior vena cava
Azygos vein
Brachiocephalic artery
Left common carotid artery
Left subclavian artery
Left and right vagus nerves
Left recurrent laryngeal nerve
Left and right phrenic nerves
Trachea
Oesophagus.
The heart and pericardium are the contents of the middle mediastinum, while the descending aorta, thoracic duct, azygos vein (on the right) and the hemiazygos vein (on the left side) are contents of the posterior mediastinum.

Question 18

Which of the following is correct regarding the diaphragm?
(Please select 1 option)
Has an aperture for the oesophagus at the level of the twelfth thoracic vertebra
Is not attached to the pericardium
Motor innervation is received from the lower six intercostal nerves
Sensory innervations are derived solely from the anterior primary rami of the third, fourth and fifth cervical nerves
Vena caval opening lies within the central tendon

Answer 18

Vena caval opening lies within the central tendon This is the correct answerThis is the correct answer
The inferior vena cava enters the pericardium through the central tendon of the diaphragm. It has an aperture for the oesophagus at the level of the tenth thoracic vertebra. It is attached to the pericardium especially over the central tendon.

The diaphragm receives both sensory and motor innervation from C3, C4 and C5 through the phrenic nerve.

Peripherally, the diaphragm also receives some sensory innervation from lower intercostal nerves.

Question 19

Which of the following is true regarding the female breast?
(Please select 1 option)
Develops lactiferous ducts at puberty
Is derived embryologically from endoderm
Is drained by the internal thoracic vein
Lies between the first and fifth rib
Lies only partially in the superficial fascia

Answer 19

Is drained by the internal thoracic vein

At the end of the first month of embryonic development the mammary gland begins to develop as a solid bud of epidermis into the underlying mesenchyme.

This primary bud occurs from the cranial part of the mammary ridges, thickened strips of ectoderm. Each primary bud give rise to several secondary buds that develop into the lactiferous ducts and their branches that make up the mammary gland.

The arteries supplying the breast are derived from

Lateral thoracic artery
Internal thoracic artery
Intercostal arteries.
The internal thoracic artery and its perforating branches supply a medial part of the breast. The lateral thoracic artery supplies a lateral part of the breast. Profound part is supplied by intercostal arteries and their branches.

The veins describe an anastomotic circle round the base of the nipple, called circulus venosus by Haller. From this, large branches transmit the blood from medial part of the breast into internal thoracic veins, and from the lateral part of the breast into lateral thoracic vein and intercostal veins.

The lymph vessels of the breast are situated into two layers (superficial and profound), making networks that are interconnected. Superficial lymph vessels transmit the lymph fluid into axillary lymph nodes.

Question 20

Which of the following is true concerning the oesophagus?
(Please select 1 option)
Drains all of its blood into the azygos and hemiazygos veins
Is 40 cm in length in the adult
Is lined by stratified squamous epithelium in the upper one-third
Is lined by transitional epithelium in the lower one-third
Passes behind the left main bronchus in the thorax

Answer 20

Passes behind the left main bronchus in the thorax This is the correct answerThis is the correct answer
Oesophagus is a muscular tube of foregut origin.

It begins at the cricoid cartilage (C6), passes through the diaphragm at T10 level and ends in the stomach at T11 level. It is 25 centimetres long. (The incisor to gastro-oesophageal junction length is 40 cm and not the length of the oesophagus).

It is lined by stratified squamous epithelium in its upper two thirds and stratified columnar epithelium in its lower third.

The normal indentations on the oesophagus are from the aortic arch, left bronchus and the diaphragm. It is narrowest at its origin.

It is supplied by:

The inferior thyroid arteries in the neck
Branches of bronchial arteries and aorta in the thorax, and
Branches from the left gastric artery.
The venous drainage similarly is also distributed:

To the brachiocephalic veins in the neck
Azygos system in the thorax, and
The lower end drains into the portal system through the cardiac and left gastric veins.
The nerve supply is from the recurrent laryngeal nerves and the middle cervical sympathetic ganglion for the upper third of the oesophagus.

The middle and lower third receive parasympathetic supply from the vagus and sympathetic supply from the thoracic sympathetic chain.

The cervical oesophagus drains into the deep cervical nodes
Thoracic oesophagus drains into tracheo-bronchial and posterior mediastinal nodes, and
The abdominal oesophagus drains into the gastric and celiac nodes.
However, the lymphatics traverse long distances within the wall of the oesophagus before draining. This is said to be the reason for synchronous or metachronous lesions seen in oesophageal cancer.

Question 21

Which of the following is true of the scalenus anterior?
(Please select 1 option)
Inserts into the scalene tubercle on the second rib
Is an accessory muscle of respiration
Is pierced by the phrenic nerve
Lies anterior to the suprascapular artery
Separates the subclavian artery and brachial plexus

Answer 21

Is an accessory muscle of respiration

The scalenus anterior is a flat muscle that arises from four slips from the four typical cervical vertebrae (C3-6) and is inserted on the scalene tubercle on the first rib. It is one of the accessory muscles of respiration, but is more important as an anatomical landmark.

Its anterior relations are:

Phrenic nerve
Ascending cervical artery
Transverse cervical artery
Suprascapular artery, and
Internal jugular vein.
The subclavian vein lies in the groove on the first rib in front of the attachment of scalenus anterior.

The trunks of the brachial plexus lie lateral to scalenus anterior.

The subclavian artery is divided into three parts:

First part is medial to it
Second part is behind (posterior) to the muscle, and
The third part is lateral to it.

Question 22

Which of the following anatomical relations of the scalenus muscles is true?
(Please select 1 option)
The ascending cervical artery lies lateral to the phrenic nerve
The phrenic nerve passes behind scalenus anterior
The subclavian artery and vein are separated by scalenus medius
The subclavian vein forms the brachiocephalic vein at the lateral border of scalenus anterior
The trunks of the brachial plexus emerge from the lateral border of scalenus anterior

Answer 22

The trunks of the brachial plexus emerge from the lateral border of scalenus anterior This is the correct answerThis is the correct answer
The ascending cervical artery, medial to the phrenic nerve on scalenus anterior, can easily be mistaken for the phrenic nerve at operation.

The phrenic nerve passes inferiorly across scalenus anterior and medius.

The subclavian artery and vein are separated by scalenus anterior.

The subclavian vein joins with the internal jugular to form the brachiocephalic vein at the medial border of scalenus anterior.

The trunks of the brachial plexus emerge from the lateral border of scalenus anterior.

Question 23

Which of the following nerve roots, if compressed by a herniated disc, would result in a diminished knee jerk?
(Please select 1 option)
	 L4
	 L5
	 S1
	 S2
	 S3

Answer 23

L4

L3/L4 nerve root compression results in a diminished knee jerk.

Question 24

The greater sciatic foramen does not transmit which of the following?
(Please select 1 option)
	 Internal pudendal vessels
	 Piriformis muscle
	 Posterior femoral cutaneous nerve
	 Sacrospinous ligament
	 Sciatic nerve

Answer 24

Sacrospinous ligament

The greater sciatic foramen transmits all of the above, apart from the sacrospinous ligament which forms part of the foramen itself and the tendon of the obturator internus muscle which passes through the lesser sciatic foramen.

Question 25

Utilising the posterior approach to perform a nephrectomy, which of the following will the surgeon find?
(Please select 1 option)
The perirenal fat is exterior to the renal fascia (of Gerota)
The peritoneum needs to be opened
The pleura reaches below the level of the twelfth rib
The renal artery is anterior to the renal vein
The subcostal nerve is anterior to the kidney

Answer 25

The pleura reaches below the level of the twelfth rib

The renal artery is posterior to the renal vein.

The kidney is retroperitoneal and the perirenal fat is enclosed in the renal fascia.

The pleura reach to the line of the lateral arcuate ligament from under which the subcostal nerve emerges, posterior to the kidneys.

Whichever approach you use the renal vein will normally be anterior to the renal artery. Occasionally the left renal vein is posterior to the aorta which can make open aortic aneurysm surgery hazardous if you have not looked carefully at the CT scan.

Question 26

Which of the following is true regarding the oesophagus?
(Please select 1 option)
Is crossed by the arch of aorta on its left and the azygos vein on the right in the superior mediastinum
Lies behind the pre-vertebral fascia at the level of the cervical vertebrae
Lies in front of the left bronchus in the superior mediastinum
Lies in front of the left lobe of liver when it enters the abdomen
Lies to the right of the inferior vena cava in the abdomen

Answer 26

Is crossed by the arch of aorta on its left and the azygos vein on the right in the superior mediastinum

The cervical portion of the oesophagus lies in front of the pre-vertebral fascia. Here it runs slightly inclined to the left of the midline, but enters the thoracic inlet along the midline in front of the body of T1 vertebrae. It then passes through the superior mediastinum, lying slightly to the left of the midline behind the left bronchus.

In the superior mediastinum, the oesophagus is crossed by the arch of the aorta on its left and the azygos vein on the right. It enters the abdominal cavity through an aperture in the diaphragm at the level of T10 vertebra.

Once the oesophagus enters the abdomen, the anterior vagal trunk and plexus, peritoneum and the posterior surface of left lobe of liver lie anterior to it and the posterior vagal trunk and plexus, diaphragm and gastrophrenic ligament lie posteriorly.

The inferior vena cava lies on the right whilst on its left are the fibres of the right crus of diaphragm.

Question 27

A cross-section CT scan cut at the level of the suprasternal notch will show which of the following?
(Please select 1 option)
Apices of the lungs
Origin of the ascending aorta
Superior vena cava entering the heart
The oesophagus lying against the body of T1
Tracheal carina

Answer 27

Apices of the lungs

At the level of the sternal notch you would expect to see the left and right brachiocephalic vein form from the subclavian and internal jugular veins.

The aortic arch reaches to just below the level of the sternal notch.

The tracheal carina is at the level of the manubrial-sternal joint.

The level of the suprasternal notch is at the lower body of T2.

Question 28

A 62 year old male complains of back pain. He has had a recent fall. Walking causes pain of the left lower leg. On examination he is noted to have reduced sensation over the knee.

Answer 28

L3

Sensation over the knee is equivalent to the L3 dermatome. The four nerves involved include the infrapatellar branch of the saphenous nerve, the lateral cutaneous nerve of the thigh, anterior cutaneous nerve of the thigh (both lateral and medial branches).

Question 29

A 42 year old woman is found to have a burst fracture of the C5 vertebral body. After a few months where would the level of injury be?

Answer 29

C6

A C5 burst fracture usually injures the C6 spinal cord situated at the C5 vertebrae and also the C4 spinal roots that exits the spinal column between the C4 and C5 vertebra. Such an injury should cause a loss of sensations in C4 dermatome and weak deltoids. Due to oedema , the biceps (C5) may be initially weak but should recover. The wrist extensors (C6), however, should remain weak and sensation at and below C6 should be severely compromised. A neurosurgeon would conclude that there is a burst fracture at C5 from the x-rays, an initial sensory level at C4 (the first abnormal sensory dermatome) and the partial loss of deltoids and biceps would imply a motor level at C4 (the highest abnormal muscle level). Over time, as the patient recovers the C4 roots and the C5 spinal cord, both the sensory level and motor level should end up at C6. Such recovery is often attributed to ‘root’ recovery.

Question 30

An 18 year old lady with troublesome hyperhidrosis of the hands and arms is due to undergo a sympathectomy to treat the condition. Which of the following should the surgeons divide to most effectively treat her condition?

	A.	Sympathetic ganglia at T1, T2 and T3
	B.	Sympathetic ganglia at T2 and T3
	C.	Sympathetic ganglia at T1 and T2
	D.	Stellate ganglion
	E.	Superior cervical ganglion

Answer 30

T2 & 3

To treat hyperhidrosis the sympathetic ganglia at T2 and T3 should be divided. Dividing the other structures listed would either carry a risk of Horners syndrome or be ineffective.

Question 31

A 53 year old man with a carcinoma of the lower third of the oesophagus is undergoing an oesophagogastrectomy. As the surgeons mobilise the lower part of the oesophagus, where are they most likely to encounter the thoracic duct?

	A.	Anterior to the oesophagus
	B.	On the left side of the oesophagus
	C.	On the right side of the oesophagus
	D.	Immediately anterior to the azygos vein
	E.	Posterior to the oesophagus

Answer 31

Posterior oesophagus

The thoracic duct lies posterior to the oesophagus and passes to the left at the level of the Angle of Louis. It enters the thorax at T12 together with the aorta.

The thoracic duct lies posterior to the oesophagus and passes to the left at the level of the Angle of Louis. It enters the thorax at T12 together with the aorta.

Thoracic duct

Continuation of the cisterna chyli in the abdomen.
Enters the thorax at T12
Lies posterior to the oesophagus for most of its intrathoracic course. Passes to the left at T5.
Lymphatics draining the left side of the head and neck join the thoracic duct prior to its insertion into the left brachiocephalic vein.
Lymphatics draining the right side of the head and neck drain via the subclavian and jugular trunks into the right lymphatic duct and thence into the mediastinal trunk and eventually the right brachiocephalic vein.
Its location in the thorax makes it prone to injury during oesophageal surgery. Some surgeons administer cream to patients prior to oesophagectomy so that it is easier to identify the cut ends of the duct.