Thorax Flashcards
What is scarpa’s fascia?
What are its boundaries?
Thin strong fascia of the anterior abdominal wall overlying the fattier Camper’s fascia.
BOUNDARIES
- Upper thoracic wall
- Lateral: mid-axillary lines
- Inferior: fascia lata from pubic tubercle to below the inguinal ligament
Turns into Colles fascia over penis and scrotum
p307
Describe the trajectory of the superior intercostal artery.
What does it supply?
Course: from costocervical trunk behind scalenus anterior
Across front of neck of first rib, lateral to sympathetic trunk.
Supplies: upper two intercostal spaces
p315
Describe the drainage of the intercostal spaces
1 posterior intercostal vein
- drains into musculophrenic and internal thoracic veins
2 anterior intercostal veins
- 1st space to supreme intercostal vein
- lower 11 spaces drain into azygos on right,
- space 2-3 to superior intercostal vein
- lower 8 hemiazygos and accessory hemiazygos on left
Describe the course of the superior intercostal vein in relation to the vagus and phrenic nerves.
L) forward over arch of aorta, superficial to vagus, deep to phrenic, empties into L) brachiocephalic
p316
Where are the aortic bodies located and what is their nervous supply?
In adventitial layer under arch of aorta near the ligamentum arteriosum. Supplied by vagal fibres.
What are the borders of the superior mediastinum?
If an infection is in the neck, how is it limited to the superior mediastinum?
thoracic inlet above
horizontal plane through manubriosternal joint
from 2nd costal cartilages to lower T4 and upper T5 vertebral bodies
prevertebral and pretracheal fasciae extend from neck into superior mediastinum. pretracheal fascia attaches to T4 vertebra limiting posterior spread to superior mediastinum.
What are the contents of the middle mediastinum?
pericardium heart great vessels lung roots phrenic nerve (part that passes between pericardium and pleura)
What is the plane between the anterior and posterior mediastinum
At the bifurcation of the trachea, concavity of aortic arch, just above the bifurcation of the pulmonary trunk
Where is the ligamentum arteriosum? Which nervous structure is closely related to it?
From left pulmonary artery to concavity of aortic arch distal to where the subclavian branches off.
Left recurrent laryngeal nerve hooks around it..
What is the nervous and arterial supply of the serous and fibrous pericardium?
SEROUS
Parietal: phrenic
Visceral: not innervated lol
Art: nil
FIBROUS
phrenic nerve
Art: pericardiophrenic and internal thoracic and pericardial (from descending aorta to ventral side)
What are the two sinuses of the parietal pericardium?
TRANSVERSE
aorta and pulmonary trunk above
pulmonary veins below
OBLIQUE
sac between two left and two right pulmonary veins and inferior vena cava
anterior wall: posterior wall of LA
fig 4.18
How is the pericardium attached to other structures?
Fused to central tendon of diaphragm
Fibrous sac connected to upper and lower ends of sternum by sternopericardial ligaments
p335
Fuses to all great vessels EXCEPT IVC (central tendon is in the way)
What are the venae cordis minimae?
Small veins in walls of all 4 chambers of the heart opening directly into their respective chambers. Most frequent in right atrium.
What is the sulcus terminalis? What does it delineate?
Between SVC and R) auricle externally. Internally is a muscle band (crista terminalis) delineating smooth to the right and ridged (pectinate muscles) to the left in the auricle.
Where is the coronary sinus?
Where is the AV node in relation?
What is Koch’s Triangle? (bonus question hehe)
to the left of the fossa ovalis
to the left of the IVC orifice
above the cusp of the tricuspid valve
AV Node is above and to the left of the opening of the coronary sinus (in the interatrial septum) in Koch’s triangle
- septal cusp of tricuspid valve
- anteromedial margin of opening of coronary sinus
- tendon of todaro
p346
Blood supply of each of the SA and AV nodes
SA: R) coronary branch (SA nodal artery)
AV: terminal branch (AV nodal artery), RCA derived in 60% of people
Which heart valves have active competency? What does that mean?
Mitral and tricuspid valves are kept competent by active contraction of papillary muscles that pull on chordae in ventricular systole.
Aortic and pulmonary valves do not have these. Competency is the result of mutual pressure between the distended cups.
What are the surface markers for the valves of the heart?
All lie vertically behind the sternum. Fig 4.26 p344
AP: behind left border at 3rd costal cartilage (pulmonary higher)
MT: behind midline of lower sternum, mitral a little higher and to the left. (4th and 5th approx)
What limits the size of cardiac muscle fibres?
Each cardiac muscle fibre is supplied by a capillary. Oxidative metabolism and mitochondrial capacity prevent hypertrophy up to a certain point.
Increase in size is not met with increase in NUMBER of capillaries.
Describe the structures surrounding the left subclavian artery and what structures separate it from the left brachiocephalic vein. At what thoracic level does it arise?
Posterior: longus colli, oesophagus, thoracic duct
Medial: trachea, left recurrent laryngeal nerve
Separating: cardiac plexus, vagus, phrenic nerve
Arises from T3/4 vertebral disc
Which veins drain coronary system of the heart and where do they empty?
CORONARY SINUS
- posterior AV groove
- opens into RA to the left of IVC
GREAT CARDIAC VEIN
- up interventricular groove, over LA and obliquely into coronary sinus
MIDDLE CARDIAC VEIN
- posteriorly into great cardiac
SMALL CARDIAC VEIN
- anteroinferiorly into lower end of coronary sinus
POSTERIOR
- of left ventricle , into great cardiac vein
OBLIQUE (Marshalls)
- posteriorly over LA into great cardiac vein
ANTERIOR
- small horizontal veins over the RA draining independently
VENAE CORDAE MINIMI
From where do they left and right crus of the diaphragm arise? Which crus encircles the oesophagus?
Left crus L1-2
Right crus L1-3
RIGHT crus encircles
What are the origins and insertions of scalenes?
Anterior scalene: anterior tubercles of transverse processes C3-C6 inserts to first rib
Middle Scalene: Posterior tubercles C2-C6 inserts to first rib
Posterior scalene: posterior tubercles C4-C6 inserts 2nd rib
In principle, the pulmonary arteries and veins follow what pattern in their path through the lungs
Arteries follow airways
Veins are spaced between the bronchi