Anatomy Exam 3 Thorax Flashcards
Describe the intercostal neurovascular bundle?
Vein is Superior Artery is Middle Nerve is Inferior Think NAV, nerve is closest to the Navel
What structures are found in the Mediastinum
- Heart
- Great Vessels
- Trachea
- Esophagus
Number of lobes R and L lungs
L - 2
R - 3
Fissure of the left lung
Oblique and divides the upper and lower lobes
Fissures of the Right lung
Oblique divides the upper and lower. Horizontal divides the superior and middle
Right lung relations
- R brachiocephalic vein
- SVC
- Pericardium of RA
- Azygous Vein
- R vagus nerve
Left lung Relations
- Pericardium
- Aorta
- L phrenic nerve
Boarders of the heart
Inferior - costal and diaphragmatic
Anterior - Costal and mediastina
Posterior - rounded and non distinct
What is the costodiaphragmatic recess?
Potential space within the pleural cavity at the junction of the inferior boarder. During forced inspiration, lung fills the void. During expiration it is filled with fluid
Describe the SNS innervation of the bronchi
The pulmonary plexus resides posterior to the lung root. SNS fibers originate in the upper thoracic ganglia, they supply smooth muscle and pulmonary blood vessles
Describe the PNS innervation of the lungs
The pulmonary plexus resides posterior to the lung root. PNS fibers are derived from the Vagus nerve and supply bronchial smooth muscle and mucous glands
Boundaries of the mediastinum
Superior - Superior Thoracic Aperture
Inferior - Diaphragm
Anterior - Sternum
Posterior - Vertebral bodies
Mediastinal divisions
Superior
Inferior
Compartments of the Inferior mediastinum
- Middle (largest)
- Anterior
- Posterior
Contents of the Middle Mediastinum
Heart and fibrous pericardium
Contents of the Anterior Mediastinum
Fat and Thymus gland remnants
Contents of the Posterior mediastinum
- Esophagus
- Descending thoracic aorta
- Thoracic Duct
- SNS trunks
Contents of the superior mediastinum
- SVC and tributaries
- Aortic Arch and branches
- Trachea
- Esophagus
- Thorasic duct
- R and L Vagus and Phrenic nerves
Neurovasculature of the fibrous pericardium
- innervation by the phrenic nerves
- Supply by internal thoracic arteries
- Drainage pericardiophrenic veins
What are the 2 reflections formed by the continuation of the visceral and parietal serous pericardium
- Transverse pericardial sinus
2. Oblique pericardial sinus
What comprises the transverse pericardial sinus?
Two sleeves
- Surrounds the ascending aorta and pulmonary trunk
- Surrounds the SVC, IVC and pulmonary veins
Right border of the heart
- RA
- Between the 3rd and 6th intercostal and 3 CM right of midline
Left border of the heart
- LV and L Auricle
- Slopes upward/ medially
- L 5th ICS to L 2nd ICS
Inferior border of the Heart
- RA and RV
- R 6th ICS to L 5th ICS
Anterior (sternocostal)surface of the heart
- RA, RV, -small strip of the LV and L Auricle
Posterior (base) Surface of the heart
- LA, small portion of RA
Inferior (diaphragmatic) surface of the heart
- RV and LV
Distinguishing features of the RA
- Right Auricle (overlaps the ascending aorta)
- Crista terminalis (anterior wall)
- Musculi pectinati (ridges)
- Fossa Ovalis (posterior/ septal wall)
- Coronary sinus drainage
- Valve of IVC (remnant of fetal development)
What is anatomically significant about the level of the 4th thoracic vertebrae
- Trachea bifurcates
- Aorta arches
- Pulmonary artery divides to left and right
What is the moderator band?
- AKA septomarginal trabeculae
- Carries part of the RBB to the anterior papillary muscle
- Thus it facilitates conduction time
Describe the Brachiocephalic veins
- Formed by the union of the subclavian and internal jugular
- Drains into the SVC
What drains into the R brachiocephalic vein?
- Right Vertebral vein
- Right Internal Thoracic Vein
What drains into the Left Brachiocephalic vein?
- Left Vertebral Vein
- Left Internal Thoracic Vein
- Superior intercostal veins
- Inferior Thyroid Vein
What drains into the SVC
- Azygous Vein
- R and L brachiocephalic
The R phrenic nerve follows what vessels
- R brachiocephalic and SVC
The L phrenic nerve follows which vessel
Lateral to the L common carotid and crosses the aortic arch
Which roots give rise to the phrenic nerves
- C3, C4 and C5
- C3,4,5 keep the diaphragm alive
Innervation of the phrenic nerve results in what
- Motor function of the diaphragm
- Sensory to the fibrous and parietal serous pericardium
- Sensory to mediastinal and diaphragmatic pleura
- Sensory to the peritoneum
Neurovasculature of the trachea
- Inferior thyroid arteries and veins
- Recurrent laryngeal nerve provides sensory and PNS
Neurovasculature of the esophagus
- Supplied by the Inferior thyroid, descending aorta and gastric arteries
- Drained by brachiocepalic and left gastric vein with azygous veins (portacaval anastomosis)
- Innervation by vagi and recurrent laryngeal branches
Path of the R vagus nerve
Enters the thorax posterior to the bifurcation of the brachiocephalic artery right of the trachea. Posterior to the R lung root and to the esophagus
Path of the L vagus nerve
Descends posterior to the L common carotid, crosses the Aortic Arch, gives of the L recurrent laryngeal and continues posterior to the L lung root to the esophagus
What do the L and R vagus nerves form when they meet
The esophageal plexus. The anterior and posterior terminal branches continue with the esophagus
Where does the Aorta leave the thorax
T12 through the diaphragm
What branches off of the Descending Thoracic Aorta
- Posterior intercostal arteries which supply 3-11 ICS then anastomose with the anterior intercostal arteries
- Bronchial Arteries
- Esophageal Arteries
Course of the Thoracic Duct
- Arises from the cysterna chili
- travels between the descending aorta and the azygous vein through the posterior and superior mediastinum
- Terminates at the confluence of L subclavian and L internal jugular veins
What areas drain into the Azygous vein
- Posterior thoracic wall
- bronchi
- pericardium
- intrathoracic esophagus
What drains the Right 1st ICS
R brachiocephalic
What drains the Right 2,3 ICS
R superior thoracic intercostal veins
What drains the left 2,3 ICS
L Superior Intercostal Vein (drains into the L Brachiocephalic)
What drains the Left 1st ICS
L Brachiocephalic Vein
What drains the right 4-11 ICS
The posterior intercostal veins
What drains the left 8-11 ICS
Hemi-Azygous Vein
What drains the left 4-7 ICS
Accessory Hemi-Azygois vein
What is a stellate ganglion
Fusion of vertebral ganglia most commonly the inferior cervical and superior thoracic
The autonomic prevertebral plexus innervates what
Thoracic structures such as the heart, lungs and esophagus
Lower thoracic ganglia form what
- Greater splanchnic
- Lesser splanchnic
- Least splanchnic
all which continue into the abdomen
Thorax Definition
The trunk comprised of; the sternum, costal cartilages, ribs, thoracic vertebrae. And the structures within
Define the thoracic outlet
The opening at the superior portion of the thorax comprised of; the first ribs, their costal cartilages and the manubrium.
What is Thoracic Outlet Syndrome
Compression of structures in the Thoracic Outlet by space occupying tumors
What is unique anatomically about the Axillary Tail of the breast?
It is the only portion of the breast which lays beneath the deep fascia
Why are the function of the fibrous septa (Ligaments of Astley Cooper) in the breast?
- To subdivide the 15-20 glandular lobes
2. To loosely attach the skin of the breast to the deep fascia of the chest wall
What are clinical findings of breast cancer?
- Dimpling of the skin due to the attachment of the fibrous septa
- Lack of mobility when the pectoris major is flexed indicates that the breast is fixed to the chest wall muscle
What is the blood supply of the breast?
- Internal Thoracic Artery
- 2nd- 4th Intercostal Arteries
- Lateral Thoracic artery
- Thoracocromial Artery
Describe the Lymph drainage of the breast
Superior and Lateral aspects drain via the infraclavicular and pectoral into the central and apical axillary nodes.
Inferior and Medial aspects drain into the bronchomediastinal trunk to the root of the neck