Thorax, Heart, Lungs etc Flashcards
What is the origin of pectoralis major?
- Medial third of clavicle.
- Sternum.
- Costal cartilages.
What are the 4 vertical lines of the chest wall called?
- Mid-clavicular.
- Anterior axillary line.
- Mid axillary line.
- Posterior axillary line.
Insertion of Pec Major
Humerus
Action of Pec Major
Adduction and medial rotation of the humerus at the shoulder.
What is the insertion of pectoralis minor?
The coracoid process of the scapula.
What is the action of pectoralis minor?
Protraction of the shoulder.
What is the insertion of serratus anterior?
Costal surface of the scapula.
What is the action of serratus anterior?
Protraction of the scapula.
What is the innervation of the intercostal muscles?
The intercostal nerves.
What is the function of the lungs?
Oxygenates blood by bringing inspired air into contact with O2 poor blood in the pulmonary capillaries.
What is the Pleural Cavity?
A Potential space between the visceral and parietal pleura. It is continuous at the Hilum of the lung
Name 2 functions of the serous fluid within the pleural cavity?
- Lubricates the pleurae.
2. Creates a surface tension helping the lungs to expand on inspiration.
Name the 4 main structures that are found at the hilum of the lung.
- Pulmonary artery x1.
- Bronchus x1.
- Pulmonary vein x2.
What branch does the right main bronchus give off outside of the right lung?
Superior lobar bronchus.
What other smaller vessels are found at the hilum of the lung?
- Bronchial arteries.
- Pulmonary plexus of autonomic nerves.
- Lymph nodes.
Which lung are inhaled foreign bodies most likely to be found in and why?
The right lung. The right main bronchus is shorter and more vertical.
How many lobes does the right lung have and what are they called?
3 lobes.
Superior, middle and inferior.
How many lobes does the left lung have and what are they called?
2 lobes.
Superior and Inferior.
What is the fissure in the left lung called?
Oblique (lies along 6th rib).
What are the fissures in the right lung called?
Horizontal (extends from mid-axiallry line anteriorly along the 4th rib) and Oblique (lies along 6th rib).
Name the 3 surfaces of the lungs.
- Costal.
- Mediastinal.
- Diaphragmatic.
What is the action of parasympathetic innervation in the lung?
Bronchoconstriction and vasodilation of pulmonary vessels.
What is the action of sympathetic innervation in the lung?
Bronchodilation and vasoconstriction of vessels that are poorly ventilated.
What is the surface marking for the apex of the lung?
2 finger breadths (3cm) above the medial clavicle in the neck.
What are the surface markings for the lower border of the lung?
6th rib anteriorly, 8th rib in the mid-axillary line and 10th rib posteriorly.
What are the 3 branches of the arch of the aorta?
- Brachiocephalic trunk.
- Left common carotid artery.
- Left subclavian artery.
What are the branches of the brachiocephalic trunk?
Right common carotid (LHS). Right subclavian (RHS).
What is the ligamentum arteriosum a remnant of and what was its function in the foetus?
Remnant of the ductus arteriosum.
It’s function was to shunt blood between the pulmonary trunk and the aorta in order to bypass the non-functioning lungs.
What branch does the left vagus nerve give off as it crosses the arch of the aorta?
The left recurrent laryngeal nerve.
Briefly describe the anatomical course of the right phrenic nerve.
Lies on large veins (brachiocephalic, SVC etc) and along the right side of the heart. Crosses in front of root of the lung.
Briefly describe the anatomical course of the left phrenic nerve.
Crosses the arch of the aorta and descends in front of the root of the lung. ANTERIOR to the hilum of the lung
What spinal roots is the phrenic nerve derived?
C3, 4 and 5 (cervical plexus).
What does the phrenic nerve supply?
Motor innervation to the diaphragm.
Sensory innervation to the pleura, peritoneum and pericardium.
Does the phrenic nerve enter the diaphragm? If so where?
Yes. It pierces the central tendon of the diaphragm alongside the IVC on the right (T8).
Does the vagus nerve enter the diaphragm? If so where?
Yes. Through the oesophageal hiatus (T10).
What are the layers of the pericardium?
- Outer fibrous layer.
- Parietal serous layer.
- Visceral serous layer.
What structures form the left border of the heart?
- Left pulmonary artery.
- Left auricular appendage.
- Left ventricle.
What is the surface marking for the apex of the heart?
5th intercostal space in the left mid-clavicular line.
On what aspect of the heart would you find the left atrium?
The posterior aspect. It is closely related to the oesophagus.
Where is the RCA found?
In the atrio-ventricular sulcus
Name the 3 main branches of the RCA.
- Sino-atrial nodal branch.
- Right marginal branch.
- Posterior inter-ventricular branch.
In 90% of hearts where does the posterior inter-ventricular artery arise from?
RCA.
In 30% of hearts where does the posterior inter-ventricular artery arise from?
The circumflex artery.
In 20% of hearts where does the posterior inter-ventricular artery arise from?
The RCA and the circumflex artery
Name the 2 main branches of the LCA.
- Circumflex.
2. Left anterior descending (LAD).
In what sulcus does the circumflex artery lie? What other large vessel can be found here?
Left atrio-ventricular sulcus.
The coronary sinus can also be found here. IT passes posteriorly and drains into the RA
Where is the SAN located?
The upper aspect of the crista terminalis in the RA.
Where is the AVN located?
Inter-atrial septum.
At what phase of the cardiac cycle do the coronary arteries fill?
Diastole; when the ventricles are relaxed.
What 2 spaces does the crista terminalis divide in the RA?
It divides the smooth walled atrium from the trabeculated auricle - ridges = musculi pecanti.
What is the Fossa Ovalis a remnant of?
The Foramen Ovale. In the foetus the foramen ovale shunted blood from the RA to the LA so as to bypass the lungs.
In the ventricles, what are the chordae tendinae attached to?
The valves (mitral or tricuspid) and the papillary muscles.
How do the mitral and tricuspid valves work?
They open passively when the atria contract and then close afterwards to prevent backflow. The papillary muscles and chordae tendinae work to keep the valves closed during ventricular contraction.
How do the atrial and pulmonary valves work
They open passively when the ventricles contract. Towards the end of systole they close to prevent the back flow of blood. The pressure of blood on the valves keeps them closed.
How would you know if the atrial and pulmonary valves were incompetent?
You would get regurgitation of blood into the ventricles. This could be heard as a diastolic murmur.
Where can you hear the pulmonary valve?
Left of the sternum, 2nd intercostal space.
Where can you hear the aortic valve?
Right of the sternum, 2nd intercostal space.
What vessels are contained within the carotid sheath?
- Carotid artery.
- Jugular vein.
- Vagus nerve.
What vertebral level is the tracheal bifurcation?
T4.
Where does the azygous vein drain into?
The superior vena cava.
What are the names of the three splanchnic nerves?
The greater (T5-9), the lesser (T10-11) and the least (T12).
Occlusion of which vessel is most likely to result in a fatal heart attack?
The left main coronary artery.
Which artery provides the main blood supply to the left ventricle?
The left anterior descending artery.
Which vessel is most likely to become occluded without producing any symptoms?
Right marginal artery.
What is the function of the pericardium?
It provides a friction free surface to accommodate the heart’s sliding movements.
Where does the Posterior Descending Coronary artery come from either 70% of the time, 20% of the time, 10% of the time?
70% of the time, it PDC comes from the Right Margnal only. 20% of the time it comes from the Circumflex only
10% of the time it comes from both!
(this means that you could technically say it comes from the Circumflex artery 30% and Right marginal 80% of the time as well)
what is the surface on the right boarder (more medail) side of the heart?
Mediastinal
what is the surface on the anterior boarder of the heart?
Sternocostal
What is the surface on the posterior surface of the heart?
Diaphragmatic
What are the 3 layers of heart tissue?
Epicardium, Myocardium, Endocardium
what is the course of the left recurrent laryngeal nerve? what does it innervate?
Hooks under aortic arch. innervates muslces in larynx apart from Cricothyroid muscle
what is the course of the recurrent laryngeal nerve? what does it innervate?
Hooks under subclavian artery, then goes up to larynx. Innervates innervates muscles in larynx apart from Cricothyroid muscle
( The cricothyroid muscle is innervated by the superior laryngeal nerve.)
What does the superior laryngeal nerve innervate?
Internal - Sensory to the laryngopharynx and superior part of the larynx.-
External - The external laryngeal nerve innervates the cricothyroid muscle of the larynx.
Phrenic and vagus nerve - what is their relation to the hilum of the lung?
phrenic ANTERIOR to hilum of lung
Vagus POSTERIOR to hilum of lung
Where would referred pain be for the diaphragm?
in the neck, as it is innervated by C3, 4,5
Valve Osculation: where would you place the stethoscope to listen to the Apex beat of the heart?
5th Intercostal Space, Down in Left Midclavicular line
Valve Osculation: where would you place the stethoscope to listen to the Aortic and Pulmonary Valves?
Pulmonary valve: 2nd intercostal space at the left sternal edge.
Aortic valve: 2nd intercostal space at the right sternal edge.
(either sides of sternum)
Where would you listen to the Mitral valve?
Mitral valve: 5th intercostal space in the left midclavicular line - Same as APEX beat
Where would you listen to the Tricuspid valve?
Tricuspid valve: 4th or 5th intercostal space at the lower left sternal edge.
What are the Internal and innermost intercostal muscles role in respiration?
They are accessory muscles. Contract in deep/laboured Inhalation, relax passively in exhalation
What is the Bucket handle represented by?
The intercostal muscles moving up wards and outwards
What is the Pump handle represented by?
The rising of the sternum anteriorly and superiorly
What level does the IVC go through the Diaphragm?
Central Tendinous ring/Caval Hiatus at T8
What level does the Oesophagus, Vagus and Oesophageal branches of the of the left gastric artery pierce through the Diaphragm?
oesophageal Hiatus, T10
What level does the abdominal aorta, Thoracic duct and Azygous vein through the diaphragm?
Aortic Hiatus, T12
What direction do the inner intercostal muscle fibres run? what about the innermost intercostal muscle Fibres?
The internal intercostal muscle fibers run in a superomedial to an inferolateral direction, whereas the innermost intercostal muscles run in more of a perpendicular direction to the ribs.
what are the orientation of the lung hilums, on the right and left?
Right lung hilum
Bronchi most posterior
Pulmonary Artery middle
Pulmonary veins anterior, and one below
Left lung hilum
Pulmonary artery most superior
Pulmonary bronchi most posterior (and in the middle )
2 x pulmonary veins most inferior
(general rules of thumb - 2x pulmonary veins below, and pulmonary bronchi most posterior) look for cartilage for bronchi!
Pulmonary artery is either then the most superior or most anterior, generally)
What can tell you if you are looking at the right or left lung?
- look for the cardiac notch On the left lung (large indentation on inner surface of left lung from the heart)
- lingula (small tongue shaped out portion on the front inferior part of left lung)
What makes up the conducting airway? (first part)
Pharynx, larynx, trachea, Lobar bronchi, Segmental bronchi, terminal bronchi
What makes up the respiratory airway?
Respiratory bronchioles, Alveolar ducts, and Alveolar sacs (these 3 make up the acinus)
what level does the trachea bifurcate? what is this called
The carina, at level T4
What goes through the diaphragm at the caval Hiatus?
Inferior vena cava
Terminal branches of right phrenic nerve
at T8 level
What goes through the diaphragm at the Oesophageal Hiatus?
Oesophagus
Right and left vagus nerves
Oesophageal branches of left gastric artery/vein
at T10 level
What goes through the diaphragm at the Aortic Hiatus?
Aorta
Thoracic duct
Azygous vein
at T12
2,3,3,
Phrenic provides sensation to 3 places. What are they?
3 p’s:
Pleura, peritoneum, pericardium
where would you find the parietal pleura?
What is it innervated by?
– on thoracic wall against lungs, phrenic innervation (nociception). Needs anaesthetizing for surgery
Continuous with Visceral pleura at root of lung
Intrapleural fluid fills space, lubricating surfaces
where would you find the visceral pleura?
What is it innervated by?
Visceral – on lung surface, autonomic innervation
HAS SENSORY FIBRES THAT DETECT STRETCH
Continuous with parietal pleura at root of lung
Intrapleural fluid fills space, lubricating surfaces
What does the RCA supply?
( SA node, AV Node, Posterior IV septum)
What does the Right Marginal supply?
(Right Ventricle and APEX)
What does the Posterior Descending Artery
(Right ventricle, Left Ventricle, Posterior 1/3 of IV septum)
What does the left circumflex artery supply?
flexes around to the posterior (Left Atria and Left Vent.)
What is the name of the muscular ridge that separates the interior surface of the right
atrium?
The interatrial septum is the muscular ridge separating the interior surface of the right atrium.
Where are trabeculae carnae found, and what is there purpose?
Located on the inner surface of the left and right ventricles, these irregular
elevations of muscle prevent suction
What marks the divisions between the upper and lower respiratory tracts?
The True vocal folds mark the division
between the upper and lower respiratory tract.
