Thorax Flashcards
1
Q
Ostium primum
A
Failure of fusion of septum primum with endocardial cushions
= osmium primum defect lying immediately above AV boundary
–> may be associated with additional VSD
2
Q
Ostium secundum
A
Septum primum successfully fuses with endocardial cushions
BUT septum primum fails to sufficiently cover primum
When septum primum and secundum fuse the defect remains
3
Q
Ventricular septal defect
A
Most common defect
Large defects occurring in membranous part of septum just below aortic valves require surgical repair
Small defects in muscular septum may close spontaneously
4
Q
Patent ductus arteriosus
A
Irregular transmission of blood between the aorta and the pulmonary artery
Requires surgical correction as it increased load on left ventricle and lead to pulmonary HTN
During surgery, left recurrent laryngeal nerve at risk
5
Q
Fallots tetralogy
A
Ventricular septal defect
Pulmonary stenosis
Overiding aorta
Right ventricular hypertrophy
Causes Right - to - Left shunt = CYANOTIC
6
Q
Developmental parts of the diaphragm
A
Septum transversum –> central fibrous tendon
Foregut mesentery –> crura and median part
Ingrowth from body wall
Pleuroperitoneal membrane
7
Q
Failure of pleuroperineal part of development of diaphragm
A
= Bochdalek hernia
more common left vs right
8
Q
Structures crossing the neck of the first rib
A
Medial –> Lateral
Sympathetic trunk
Superior intercostal artery
T1 of brachial plexus
9
Q
Intercostal muscle layers
A
External intercostal: down and forwards
Internal intercostals: down and backwards
Neurovascular bundle lies here
Innermost intercostals: overlap more than one space
10
Q
Levels of trachea
A
C6 –> T5
11cm
11
Q
Lining of trachea
A
Columnar ciliated epithelium
Cartilaginous rings, open posteriorly U-shaped
12
Q
Trachealis
A
Muscle connecting open ends of U-shaped tracheal cartilage
13
Q
Azygous vein
A
RIGHT SIDED
arches over right main bronchus
14
Q
Right bronchus
A
Shorter, 2.5cm
Wider
More vertical
Azygous vein arches over right main bronchus to enter SVC
Pulmonary artery below then anterior to it
Branches to upper bronchus before entering lung
Divides into middle and lower bronchus within lung
15
Q
Left bronchus
A
Longer, 5cm
Branches into upper and lower once in lung
Pulmonary artery lies anterior and then above
16
Q
Lingula of the lung
A
Left lung equivalent of the middle lobe
-lies between cardiac notch and oblique fissure
17
Q
Bare areas of pleura
A
Medial end of 4th and 5th intercostal spaces
18
Q
Lower borders of the lung
A
6th rib in the midclavicular line
8th rib in the midaxillary line
10th rib at the lateral border of erector spinae
19
Q
Location of oblique fissure
A
T5 - 6th intercostal
~4cm from midline
20
Q
Location of horizontal fissure
A
Right lung
-passes horizontally and medially from the oblique fissure at the level of the 4th costal cartilage
21
Q
Pericardiocentesis without entering pleura
A
A needle passing through the left 4th and 5th
intercostal spaces immediately lateral to the sternal
edge will enter the pericardium without traversing
the pleura
22
Q
Medial arcuate ligament
A
Condensation of fascia of psoas major
Join anteriorly over aorta
23
Q
T10 diaphragmatic opening
A
Oesophagus
Vagus nerves
Branches of left gastric artery and vein
24
Q
Sympathetic chain enters through diaphragm…
A
Passes behind median arcuate ligament on substance of psoas major
25
Greater and lesser splanchnic nerves enters through diaphragm...
Greater and lesser splanchnic nerves pierce the
| crura
26
Accessory muscles of inspiration
Sternocleidomastoid
Scalenes
Pectoralis major
Pectoralis minor
Serratus anterior
27
Three surfaces of the heart
Antrior:
- Rigth atrium
- Right ventricle
- Narrow strip of left ventricle
- Auricle of left atrium
Posterior / base:
- Left ventricle
- Left atrium with 4 pulmonary veins entering it
Inferior / diaphragmatic :
- Rigth atrium with IVC entering it
- Lower part of right + left ventricles
28
Three borders of the heart
Right border
-Right atrium with IVC and SVC
Inferior border
- Right ventricle
- Apex of left ventricle
Left border
- Left ventricle
- Auricle of left atrium
29
Blood entering right atrium
Recieves blood from:
- SVC
- IVC
- Coronary sinus
- Anterior cardiac vein
30
Crista terminalis
RIGTH ATRIUM:
Runs between cavae-muscular ridge
Separating:
-Smooth-walled posterior part of atrium derived from sinus venosus
WITH
-Rougher area with pectinate muscles derived from atrium
31
Fossa ovalis
Site of fetal foramen ovale
Oval depression in intra-atrial septum
32
Leaflets of the tricuspid valve
Septal
Anterior
Posterior
33
Chordae tendinae
Present in right ventricle
Attach leaflets of tricuspid valves to papillary muscles within right ventricle
Prevent eversion of the tricuspid valve during ventricular contraction
34
Moderator band
RIGHT VENTRICLE
Muscle bundle crossing from the interventricular septum to the anterior wall of the hear
- Prevents over-distension of ventricles
- Conducts right branch of AV bunclde to anterior ventricular wall
35
Auricle of the left atrium
Extends forwards and to right and wraps overlapping pulmonary trunk
36
Left atrium
In the left atrium, the pectinate muscles, fewer and smaller than in the right atrium, are confined to the inner surface of its atrial appendage
Smaller than the right.
Consists of principal cavity and auricle
Four pulmonary veins open into the cavity (two from
each lung: superior and inferior)
Shallow depression on septal surface corresponds
to fossa ovalis of right atrium
37
Left ventricle
Three times thicker vs right
Chordae tendineae run from the ventricular surfaces
of cusps to papillary muscles
38
Cusps of mitral valve
Two cusps
Anterior - larger
Posterior
39
Aortic sinuses
Right coronary artery = anterior sinus
Left coronary artery = left posterior sinus
40
Location of sinoatrial node
Situated right atrial wall at upper end of crista terminalis
41
Location of AV node
Inter-atrial septum immediately above opening of coronary sinus
42
Right coronary artery
Arises from anterior aortic sinus
Passes to the right of pulmonary trunk between it and teh auricle of left atrium
Runs along atrioventricular groove around inferior border of the heart
--> anastomoses with left coronary artery at posterior interventricular groove
Branches
- Marginal branch, along lower border
- Posterior interventricular // posterior descending
- -> runs forward in interventricular groove to anastomose with branch of left coronary artery
43
Branches of right coronary artery
Branches
-Marginal branch, along lower border
- Posterior interventricular // posterior descending
- -> runs forward in interventricular groove to anastomose with branch of left coronary artery
44
Left coronary artery
Arises from left posterior sinus
Passes to left of pulmonary trunk to AV groove
Lies under cover of the left auricle where it divides into two equally sized branches.
-Anterior interventricular branch // left anterior descedning
--> runs down to apex in anterior interventricular groove supplying wall of ventricle
--> anastomoses with posterior interventricular branch
-Circumflex: continues round the left side of
the heart in the AV groove to anastomose with
the terminal branches of the right coronary
artery.
Larger vs RCA
45
Branches of left coronary atery
Lies under cover of the left auricle where it divides into two equally sized branches.
- Anterior interventricular branch // left anterior descedning
- -> runs down to apex in anterior interventricular groove supplying wall of ventricle
- -> anastomoses with posterior interventricular branch
-Circumflex: continues round the left side of
the heart in the AV groove to anastomose with
the terminal branches of the right coronary
artery.
46
‘Left dominance’
Left coronary and circumflex arteries may be larger
and longer than usual and give off the posterior
intraventricular artery before anastomosing with the
right coronary artery, which is smaller than usual
Rigth dominance is normal, 90%
47
‘Left dominance’
Left coronary and circumflex arteries may be larger
and longer than usual and give off the posterior
intraventricular artery before anastomosing with the
right coronary artery, which is smaller than usual
-10%
Rigth dominance is normal
48
Co-dominance
Right and left have equal contributions to posteiror interventricular artery
-10%
49
Three branch left main stem vairant
Left main stem may divide into three vs two branches
-3rd lies between the anterior interventricular and
circumflex arteries and may be large
-supplying the lateral wall of the left ventricle
50
Blood supply to SA node
60% population: right coronary artery
40%: circumflex artery of LCA
3% - dual supply
51
Blood supply to AV node
90%: supplied by right coronary artery
10%: circumflex artery of LCA supply
52
Coronary sinus
Main venous drainage
Lies in posterior atrioventricular groove
Drains into rigth atrium just to left of IVC
Tributaries of coronary sinus:
-great cardiac vein: ascends in anterior interventricular
groove next to anterior interventricular artery
-middle cardiac vein: drains posterior and inferior
surfaces of heart and lies next to the posterior interventricular artery
-small cardiac vein: accompanies marginal artery
and drains into termination of coronary sinus.
53
Venous drainage of the heart
Coronary sinus: main drainage
Venae cordis minimae: tiny veins draining directly into chambers of heart
Anterior cardiac veins: small veins that open up directlty into rigth atrium
54
Tributaries of the coronary sinus
Great cardiac vein: ascends in anterior interventricular groove next to anterior interventricular artery
Middle cardiac vein: drains posterior and inferior surfaces of heart, lies next to posterior interventricular artery
Small cardiac vein: accompanies marginal artery
and drains into termination of coronary sinus
55
Pericardium fusion sites
Apex: fuses with adventita of great vessels
Base: fuses with central tendon of diaphragm,
56
Level of pericaridum
T5 - T8
3rd to 6th costal cartilages
57
Transverse sinus of heart
Lies between the aorta and pulmonary trunk in front,
| and the SVC and left atrium behind.
58
Oblique sinus of heart
Bounded by the pulmonary veins
Forms a recess between pericardium and left atrium
59
Surface anatomy of the heart
Superior:
line from second left costal cartilage
to third right costal cartilage
Inferior:
line from the sixth right costal cartilage
to fifth left intercostal space, 9 cm from midline
60
Border between superior and inferior mediastinum
Angle of Louis
| T4/T5
61
Anatomical points at the Angle of Loius
Start and end of arotic arch
Bifurcation of trachea / end of trachea
Junction of superior and inferior mediastinum
Second intercostal joint / cartilage
Confluence of azygous vein and SVC (over rigth main bronchus)
Throacic duct passes from right to left
Ligamentum arteriosum
62
Level of superiormargin of manubrium
T 2 / T3
63
Level of joint between costal margin and sternum
T9 / T 10
Posterior margin of inferior thoracic aperture (T 12) is inferior to anterior magrin (joint of costal cartilage with sternum)
64
Superior margin of diaphragmatic proction
5th rib
65
Superior mediastinum level
T1 --> Angle of Louis T4/T5
66
Inferior mediastinum level
From T4/T5 to diaphragm
Split into
- Anterior
- Middle / pericardium
- Posterior
67
Dermatone over xiphoid process
T6
68
Dermatome over umbilicus
T10
69
Lactiferous ducts
Mammary glands consist of a series of ducts and secretory lobules
These ocnverge onto 15 - 20 lactiferous ducts that open indenendently on the nipple
70
Ligaments of Cooper
=suspensory ligaments
Exten from dermis of skin to pectoral fascia
Fluid accumulation within breast tissue and tensioning of ligaments --> peau d'orange = malignancy
71
Retromammary space
Layer of loose conective tissue that seperates breast from deep pectoral fascia
72
Base of attachment of breast
Ribs II - VII
2- 7
Sternum -->
Extend to mid-axillary line
73
Innervation of breast
2nd to 6th intercostal nerves
74
Innervation of nipple
4th intercostal nerve
75
Drainage of axillary nodes
75% lymphatic drainage from breast
Axillary nodes drain into subclavian trunks
76
Innervation of pectoralis major
Innervated by medial and lateral pectoral nerves
O:
- medial half of clavicle
- anterior surface of sternum
- costal cartilages 1 - 7
- aponeurosis of external oblique
I: lateral lap of intertubercular sulcus of humerus
F: adduction, medial rotation and flexion of the humerus
77
Innervation of pectoralis minor
Innervated by medial pectoral nerve
O: anterior surface of 3rd, 4th and 5th ribs
+ deep fascia overlying intercostal spaces
I: coracoid process of scapula
F: depresses tip of shoulder and protracts scapula
78
Innervation of subclavius
Innervated by nerve to subclavius
O: 1st rib at junction between rib and costal cartilage
I: groove on inferior middle third of clavicle
F: pulls clavicle medially to stabilise sternoclavicular joint
79
Three rib articulations with vertebral bodies
Two demofacets: corrospond with facets on head of rib
Inferior costal facet of vertebrae = part of head of rib below
Supeior costal facet of vertebrae = part of head of own rib
=costotransverse joint
Transverse costal facet at end of transverse process: articulates with tubercle of own rib
80
Variants in rib articulation
1st rib
- head articulated with superior and inferior facet on T1
i. e. does not articulate with vertebral body above C7
T 10 lacks inferior demifacets: only articulates with its own rib
T 11 often lacks infeiro demifacet
T 11 and T 12 lack transverse costal facets and inferior demifacets: both wholy articulate with their own rib just at the head
81
True ribs
1 - 7
82
False ribs
8 -12
11 - 12 = floating
83
Facets on head of rib
Separated by crest
Superior = smaller, articulates with inferior costal facet of vertebrae ABOVE
Inferior = larger, articulates with superior costal facet of OWN vertebra
84
Distinct features of 1st rib
Only articulates with T1
-one vertebral articulation
Scalene tubercle
Anterior groove
-sibclavian vein
Posterior groove
-subclavian artery
85
Facets of the body of the sternum
Upper demifacet - lower portion of rib 2
4 full facets for ribs 3 - 6
Lower demifacet - upper portion of rib 7
86
Attachment of crest of head of rib
Intra-articular ligament
Connects crest of head to intervertebral disc
Splits the joint into two synovial capsules: superior and inferior
87
Ligaments of rib articulation to vertebral body
Three
Costotransverse ligaments
- medial to costotransverse joint
- neck of rib to transverse process
Lateral costotransverse ligaments
- lateral to costotransverse joint
- transverse process to tubercle of rib
Superior costotransverse ligaments
superior surface of neck --> transverse process of vertebra above
88
1st sternocostal joint
Fibrocartilagenous
ALL OTHERS ARE SYNOVIAL
89
Internal thoracic arteries
Major branch of subclavian arteries
Passes anteriorly over dome of pleura and descends through superior thoracic apertue
1cm lateral to sternum
Anterior intercostal arteries branch off during descent
Two terminal branches
- Superior epigastric artery
- Musculophrenic artery
90
Anterior intercostal arteries
Lateral branches of internal thoracic artery
Supply upper six intercostal spaces
91
Musculophrenic artery
Terminal branch of internal throacic artery
Supplies lower six intercostal spaces
92
Intercostal node drainage
Upper six: bronchomediastinal
Lower six: thoracic duct
93
Intercostal nerves
Anteriro rami T1 - T11
94
Subcostal nerve
= anterior rami of T12
95
Branches of intercostal nerves
Lateral cutaneous branch
- Largest
- Pierces thoracic wall and divides into anterior and posterior branch
- Innervates overlying skin
Anterior cutaneous branch
- Emerge parasternally
- Supply skin over sternum
96
Intercostobrachial nerve
=Lateral cutaneous branch of second intercostal nerve
Contributes to somatic innervation of medial surface of upper arm
97
Level of xiphoid
T8 - T9
98
Main blood supply to diaphragm
Inferior phrenic arteries
99
Contents of each lung root
A pulmonary artery
Two pulmonary veins
A main bronchus
Bronchial vessels
Nerves
Lymphatics
100
Vagus nerve passes .... to root of lung
Both vagus nerves pass POSTERIORLY to roots of lung
101
Phrenic nerve passes ... to root off lung
Both phrenic nerves pass ANTERIORLY to roots of lung
102
Right main brinchus branhces...
In root of lung prior to entering lung
103
Surface marking of RIGHT oblique fissure
Spinous process T4
- ->crosses 5th interspace laterally
- -> follows contour of rib 6 anteriorly
104
Surface marking of LEFT oblique fissure
More oblique vs right
Curved line between spinous process T3/4
- -> 5th interspace laterally
- ->follows contour of rib 6
105
Bifurcation of pulmonary trunk
Angle of Louis
T4/T5
LEFT of midline
LEFT of bifurcation of trachea
106
Right pulmonary artery
Longer vs left
Passes anterior to right main bronchus
Passes posteriorly to ascending aorta, SVC and upper right pulmonary vein
In root of lung gives off superior branch to superior lobe
Continues into hilum, giving off another branch the recurrent branch of superior lobe
Then divides into middle and inferior lobes
107
Pulmonary veins
On each side:
- Superior pulmonary vein
- Inferior pulmonary vein
Carries blood back to left atrium
108
Bronchial arteries
1 right
-right bronchial artery from 3rd posterior intercostal artery
2 left
- left brocnhial arteries branch directly from anterior surface of throacic aorta
- -> superior left bronchial artery = T5
- -> inferior left bronchial artery = inferior to left bronchus
109
Bronchial veins
Drain into either pulmonary veins or left atrium
--> creates a shunt
OR superior intercostal vein / hemizygous vein
RIGHT
into azygous vein
