Resp 3 - Anatomy 3 Flashcards
Name the intercostal muscles from superficial to deep:
External
Internal
Innermost
In what direction do the fibres of the External Intercostal muscles run? What is their role?
Down and anteriorly
Pull ribs up and out = 30% chest expansion during quiet respiration
In which direction do the fibres of the Internal and Innermost Intercostal muscles run? What is their role?
Down and posteriorly
Pull ribs down during forced expiration
What do the intercostal nerves supply?
- Intercostal muscles
- Parietal pleura
- Overlying skin
Define the origins of the diaphragm:
- Xiphoid process
- Interior 7-12 costal cartilages
- Arcuate ligament
- Crura of diaghragm
What is the insertion of the diaphragm?
Central tendon of the diaphragm
Which 2 muscles are responsible for chest expansion in quiet respiration?
1) External Intercostal muscles ~ 30%
2) Diaphragm ~ 70%
Which nerve supplies the diaphragm? What are its roots?
Phrenic nerve
C3, C4, C5 keeps the diaphragm alive
How many openings does the diaphragm have, what structures pass through them?
3:
@ T8 = Inferior Vena Cava
@ T10 = Oesophagus
@ T12 = Abdominal Aorta
At which spinal level does the Aorta pass through the diaphragm?
T12
At which spinal level does the IVC pass through the diaphragm?
T8
At which spinal level does the oesophagus pass through the diaphragm?
T10
In what order do the intercostal nerves, arteries and veins run along the ribs from superior to inferior?
Vein, Artery, Nerve (VAN)
Where should a needle be inserted for pleural aspiration/chest drain, and why?
Upper border of rib, to avoid intercostal neurovascular supply
Which arteries supply the parietal pleura?
Intercostal arteries
Where do the Intercostal arteries arise from?
Anterior segment = Internal Thoracic artery
Posterior segment = Superior Intercostal artery
Where do the intercostal veins drain into?
Anterior segment = Internal Thoracic vein
Posterior segment: RHS = Azygos, LHS = Hemiazygous
How much pleural fluid is usually present?
~ 10-20 ml
Name the 3 reflections of the pleura:
Anterior = Sternal Posterior = Vertebral Inferior = Costal
What is responsible for producing and absorbing pleural fluid?
Capillaries of parietal surface = Produce pleural fluid
Parietal lymph nodes = Absorb pleural fluid
What are the main functions of the pleural fluid?
- Reduce friction
- Create surface tension = cohesion (when chest expands, so does lungs)
What is the blood supply to and from the visceral pleura?
Bronchial arteries
Bronchial veins
What is the main difference between the nerve supply to the parietal and visceral pleura?
Parietal = Somatic and Autonomic Visceral = Autonomic only (no pain)
What is the Carina?
Ridge at the base of the trachea which separates the L and R bronchi
What is the name of the ridge separating the entrances to the R and L bronchi?
Carina
How many lobar bronchi are there in each lung?
Right lung = 3
Left lung = 2
What is the name of the airway supplying each bronchpulmoanry segment?
Segmental bronchi
What is a bronchopulmonary segment?
Pyramidal area of lung, each supplied by a segmental bronchus, artery and vein. (Branches of pulmonary and bronchial)
How are bronchopulmonary segments useful in surgery?
Can be isolated and removed with minimal bleeding, air leakage or interference with other segments
Where do the Bronchial arteries arise from?
Right = 3rd Intercostal artery Left = Aorta
How is the blood supply to the lungs maintained after a pulmonary embolus?
Anastamoses are present between the pulmonary and bronchial arteries (dual blood supply)
Which veins drain most of the blood supplied by the Bronchial arteries?
Pulmonary veins
Name the parasympathetic nerve which has afferent and efferent fibres in the lungs:
Vagus nerve
Name the 2 lymphatic plexuses in the lungs, and the lymph node they drain to:
1) Superficial sub-pleural lymphatic plexus (deep to visceral pleura)
2) Deep bronchopulmonary lymphatic plexus (in submucosa of bronchi and peribronchial tissue)
Hilar lymph nodes
Define the mediastinum:
Central compartment of thoracic cavity, between the 2 pleural sacs
Name the 4 divisions of the mediastinum:
1) Superior
2) Anterior
3) Middle
4) Posterior
Name the borders of the superior mediastinum:
Superior = Thoracic inlet Inferior = Sternal angle line Anterior = Manubrium Lateral = Pleural sacs Posterior Vertebral bodies T1-4
Name the contents of the superior mediastinum:
- Great vessels
- Nerves (Vagus, Phrenic, Cardiac and sympathetic trunk)
- Oesophagus
- Trachea
- Thymus
- Thoracic duct
Name the borders of the anterior mediastinum:
Superior = Sternal angle line Inferior = Diaphragm Anterior = Body of sternum and Transverse Thoracis muscles Lateral = Mediastinal pleura (part of parietal pleura) Posterior = Pericardium
Name the contents of the anterior mediastinum:
Nothing
Except Thymus in childhood - receeds in adulthood
Name the borders of the middle mediastinum:
Superior = Sternal angle line Inferior = Diaphragm Anterior = Anterior margin of Pericardium Lateral = Mediastinal pleura Posterior = Posterior margin of Pericardium
Name the contents of the Middle Mediastinum:
- Heart + Pericardium
- Tracheal bifurcation + L/R bronchi
- Great vessels
- Nerves (cardiac plexus + phrenic)
- Tracheobronchial lymph nodes
Name the borders of the Posterior Mediastinum:
Superior = Sternal angle line Inferior = Diaphragm Anterior = Posterior margin of the Pericardium Lateral = Mediastinal pleura Posterior = Vertebral bodies T5-12
Name the contents of the Posterior Mediastinum:
- Thoracic Aorta
- Thoracic duct
- Oesophagus
- Azygos vein system
- Sympathetic trunk
