Thorax anatomy Flashcards
(95 cards)
1
Q
What anatomical landmark splits the mediastinum into superior and inferior?
A
Sternal angle (angle of Louis)
Found at L4/L5
2
Q
How is the inferior mediastinum further divided?
A
Anterior mediastinum
Middle mediastinum
Posterior mediastinum
3
Q
What structures are found in the Superior mediastinum?
A
There are 10
- SVC
- Brachiocephalic vein
- Arch of aorta
- Thoracic duct
- Trachea
- Oesophagus
- Thymus
- Vagus nerve (CNX)
- Phrenic nerve
- Left recurrent laryngeal nerve
4
Q
What are the 3 structures that lie in the Anterior mediastinum
A
Thymic remnants
Lymph nodes
Fat
5
Q
What are the structures found in the middle mediastinum?
A
- Pericardium
- Heart
- Aortic root
- Arch of azygos vein
- Main bronchi
6
Q
What structures are found in the Posterior mediastinum?
V DATES
A
V DATES
- Vagus nerve
- Descending aorta (Thoracic aorta)
- Azygos vein
- Thoracic duct
- Esophagus
- Sympathetic nerve trunks / Splanchic nerves
7
Q
What is the posterior boundary of the posterior mediastinum?
A
Last 8 thoracic vertebra
T5-T12
8
Q
What are the anterior and lateral borders of the posterior mediastinum?
A
Anteriorly: Heart + Pericardium
Laterally: Lung pleura
9
Q
If a patient had a stab wound to the sternal angle (L4-L5), what structure is most at risk of injury?
A
Arch of the aorta
10
Q
What anatomical structures are found beneath the upper part of the manubrium?
A
- Left common carotid
- Left brachiocephalic vein
- Left subclavian artery
- Brachiocephalic artery
11
Q
Which rib is found at the sternal angle?
A
2nd rib
12
Q
What is the most common site for injury of the Thoracic duct?
A
When crossing to the midline at the sternal angle
13
Q
During an oesophagectomy, where would the chyle accumulate if the thoracic duct is injured?
A
Posterior mediastinum
14
Q
At what levels of the vertebrae does trachea begin and end?
A
C6 - T5 (upper border)
15
Q
What is the arterial supply and venous drainage of the trachea?
A
Inferior thyroid arteries
Thyroid venous plexus
16
Q
What lies posterior to the trachea?
A
Oesophagus and vagus nerve
17
Q
What structures lie anterior to the trachea?
A
- Isthmus of thyroid
- Inferior thyroid veins
- Sternothyroid
- Sternohyoid
- Cervical fascia
- Anastomosing branches of the anterior jugular veins
18
Q
What structures run laterally to the trachea?
A
Common carotids
Right and Left thyroid lobes
Inferior thyroid arteries
Recurrent laryngeal nerves
19
Q
At which levels does the oesophagus begin and end?
A
C6 - T11
Pierces the diaphragm at T10
20
Q
What kind of epithelium is found in the oesophagus?
A
Non-keratinised stratified squamous epithelium
It has no serosa and so holds sutures poorly
21
Q
Where are the 4 areas of constriction of the oesophagus and distance from front incisors?
A
Cricoid cartilage: 15cm
Arch of the aorta: 22.5cm
Left principal bronchus: 27cm
Diaphragmatic hiatus: 40cm
22
Q
How is the oesophagus divided?
A
Divided into Upper (cervical), Middle (thoracic) and Lower (abdominal) thirds
23
Q
What is the blood supply of the upper third of the oesophagus and its lymphatic drainage?
A
Arterial: Inferior thyroid artery
Venous: Inferior thyroid vein
Lymphs: Deep cervical
24
Q
What is the blood supply and venous drainage of the middle third of the oesophagus?
A
Arterial: Aortic branches
Venous: Azygos branches
Lymphs: Mediastinal
25
What is the blood supply to and from the lower third of the oesophagus?
Arterial: Left gastric
Venous: Left gastric vein
Lymph: Gastric
26
In which part of the oesophagus do oesophageal varies arise?
Lower third
27
What is the nerve supply of the oesophagus?
Upper half: Recurrent laryngeal nerve
Lower half: Vagus (oesophageal plexus)
28
How many lobes are there in the left and right lung?
Left: 2
Right: 3
29
What is found above the hilum of the right lung?
Azygos vein and groove for the SVC
30
Where does the oesophagus lie in relation to the hilum of the right lung?
The oesophagus sits in a vertical groove posterior to the hilum
31
What structure lies anterior to the hilum of the left lung?
- Phrenic nerve
- Vagus nerve
32
What structure is found superior to the hilum of the left lung?
Aortic arch and more superiorly, the groove accommodating the left subclavian artery
33
What structure runs posterior to the hilum of the left lung?
Descending aorta
34
What is the posterior border of the lung cavity?
Transverse process of C7 - T10
35
At what costal level is the cardiac notch found?
Left lung deviates laterally from the sternum at the 4th costal cartilage to form the cardiac notch
36
At what vertebral levels are the hillas of the lung found?
T5, T6, T7
37
At what rib level does the lung end?
10th rib
38
Injury to the posterior 8th rib would cause injury to which structure?
Lung
39
Which vertebral levels does the oblique fissure of the lung originate from and where does it end?
T3/4 to T6
40
What are the most anterior structures in the hilum of the lung?
Pulmonary artery and vein
41
What structures lie most posteriorly in the lung hilums?
Main bronchus
42
What structures are found in the hilum of the lung?
- Pulmonary artery and vein (most ant)
- LN
- Bronchial artery and vein
- Autonomic nerves
- Main bronchus (most post.)
43
What is the name of the fascia that covers the lung apex?
Sibsons fascia
44
What are the 3 structures found in the intercostal space and based on this, where should a chest tube be inserted in relation to the rib?
VAN (from superior to inferior)
Intercostal Vein
Intercostal Artery
Intercostal Nerve
Insert tubes ABOVE the rib as structures are found directly below the rib
45
What is the most likely source of bleeding after insertion of a chest drain?
Intercostal artery
46
Where is the safest site for needle decompression and chest drains?
5th intercostal space, anterior to the mid-axillary line
47
What sensation is the visceral pleura sensitive to?
Stretch (supplied by autonomic fibres from the pulmonary plexus)
48
What sensations is the parietal pleura sensitive to?
Pain, Pressure, Temperature and Touch
49
What is the nerve supply of the costal pleura?
Intercostal nerves
50
What is the nerve supply of the mediastinal pleura?
Phrenic nerves
51
What is the thoracic continuation of the cisterna chyli?
Thoracic duct
52
At which vertebral level does the thoracic duct enter the thorax?
T12
53
What is the course of the thoracic duct?
- Enters thorax at T12
- Lies posterior to the oesophagus and passes to its left at T5
Lies within the posterior and superior mediastinum
54
Where does the lymphatic drainage of the left side of the head and neck join with the thoracic duct?
Just prior to its insertion into the left brachiocephalic vein
55
Why do some surgeons administer a cream coloured liquid to patients prior to an oesophagectomy?
The thoracic duct is colourless and lies closely to the oesophagus.
The cream aids with visualising the thoracic duct
56
What are the nerve roots of the phrenic nerve?
C3, 4, 5
57
What is the route of the right phrenic nerve?
- Travels down alongside internal jugular vein
- Crosses anterior to scalenus anterior and anterior to the 2nd part of the subclavian artery
- Runs posterior to the subclavian vein and internal thoracic artery to enter thorax
- In the superior mediastinum, travels anterior to Rt. Vagus and laterally to SVC
- In the middle mediastinum, travels to the right of the pericardium and passes over the Rt Atrium
- Exits diaphragm at T8 via vena cava hiatus
58
What is the path of the left phrenic nerve?
- Travels down alongside internal jugular vein
- Crosses anterior to 1st part of subclavian artery
- Runs posterior to the subclavian vein and internal thoracic artery to enter thorax
- Passes lateral to aortic arch and left ventricle and anterior to left hilum of the lung
- Pierces diaphragm alone
59
What are the 3 papillary muscles that attach to the Chordae tendanae and where are they found?
Found in the ventricles of the heart
- Anterior papillary
- Posterior papillary
- Septal papillary
60
What are the anatomical relations of the Transverse sinus of the heart?
Anteriorly lies: Aorta & Pulmonary trunk
Posterioly lies: SVC & Lt atrium
61
Where is the oblique sinus of the heart found?
Between the pericardium and left atrium
62
What makes up the inferior (diaphragmatic) surface of the heart?
Rt ventricle + part of Lt ventricle at apex
63
What makes up the anterior surface of the heart?
Rt atrium and Rt ventricle + part of Lt ventricle
64
A stab injury to the right side of the sternum would likely injure which part of the heart?
Rt atrium
Rt border of the heart is made up of the right atrium
65
What are the auscultatory areas of the heart?
All Patients Take Meds
Aortic: Rt 2nd ICS parasternally
Pulmonary: Lt 2nd ICS parasternally
Tricuspid: Lt 5th ICS parasternally
Mitral: Lt 5th ICS mid-clavicular line
66
What is the surface anatomy of artificial valve locations?
Aortic, Mitral, Tricuspid (AMT) - all parasternal
Aortic: Rt, 3rd ICS
Mitral: Lt, 4th ICS
Tricuspid: Rt 5th ICS
67
Where do the left and right coronary arteries arise from?
RCA: from ANTERIOR sinus of ascending aorta
LCA: from POSTERIOR sinus of ascending aorta
Both arise just above the aortic valve
68
What are the branches of the RCA?
- SA nodal art (60% of supply to SAN + Rt atrium)
- Rt marginal (rt ventricle)
- Posterior Intraventricular art (IV septum)
- AV nodal art (AVN)
69
What are the branches of the LCA?
- Circumflex art (gives rise to Left marginal aka Obtuse marginal artery (Lt ventricle) + SA nodal art (40% of supply to SAN))
- LAD aka Anterior Intraventricular art (RV + LV + IV Septum)
70
What 3 veins drain into the coronary sinus prior to draining into the right atrium and what is their path?
- Great cardiac vein: anterior inter-ventricular groove
- Middle cardia vein: posterior inter-ventricular groove
- Small cardiac vein: runs with marginal artery
71
Where does the anterior cardiac vein drain into?
Directly into Right atrium
72
What is the parasympathetic supply of the heart?
Right Vagus nerve - Indirect innervation
73
Where does the sympathetic supply of the heart originate from?
Cervical and Upper thoracic portions of the sympathetic trunks (Cardiac plexus - Direct innervation)
74
What are the first 2 main arteries that arise from the ascending aorta?
RCA and LCA
75
Where is the arch of the aorta found and what 4 vessels does it give rise to?
Arch is in the Superior Mediastinum (T4)
- Brachiocephalic (branches into Right subclavian and Right common carotid)
- Left common carotid
- Left subclavian
- Sometimes Thyrida ima artery
76
Which vessel is most at risk after a fracture injury to the medial third of the right clavicle?
1- Right subclavian vein
2- Right subclavian artery
77
Where does the descending aorta start and end?
Starts in the posterior mediastinum at T4 and ends at T12 (becomes abdominal aorta)
78
What 3 structures pierce the diaphragm and at what vertebral levels does this occur?
IVC: T8
Oesophagus + vagus: T10
Aortic hiatus: T12
79
When is the mediastinum considered to be widened?
greater than 6-8cm
80
What is the likely cause of a widened mediastinum in a patient with no trauma?
Aortic dissection of the Ascending aorta
81
What is the likely cause of a widened mediastinum in a patient who has suffered trauma?
Aortic dissection of the Isthmus (beginning of the Descending aorta)
82
What is the course of the vena azygos?
- Begins posterior to the IVC at L2
- Pierces diaphragm through aortic hiatus at T12
- Lies posterior to oesophagus at T4
- Crosses the oesophagus ABOVE the root of the lung before draining into SVC
83
How many intercostal veins are there?
11
the 12th vein is called Subcostal vein
84
Where do the first 3 left intercostal veins drain into?
Left brachiocephalic vein
85
What area of the body does the T1 dermatome correspond to?
Medial side of forearm
86
What is the dermatome of the umbilicus?
T10
87
What is the conus arteriosus?
Infundibulum - smooth walled outflow tract of the right ventricle leading to the pulmonary trunk
88
Where are trabeculae carnae found?
Right ventricle
89
From which structure is the central tendon of the diaphragm derived?
Septum transversum
90
What is the embryological origin of the pulmonary artery?
6th pharyngeal arch
91
Which structure is responsible for co-ordination of contraction of papillary muscles and where is it found?
Moderator band
Found in Rt ventricle
92
What vein drains the lateral wall of the left ventricle?
Left marginal vein
93
Through which structure is a cardioplegic agent delivered in retrograde?
Coronary sinus
94
What is the most likely site of origin of a ventricular septal defect?
Perimembranous
95
What arterial supply determines dominance of left coronary artery?
PDA
Posterior interventricular artery
