Anatomy of the Thorax 7 Flashcards
What are the three internal compartments of the thoracic cavity?
- Central Mediastinum (and heart)
- Left Pleural cavity (and lung surrounded by 2 layers of simple squamous and the fluid filled pleural cavity)
- Right Pleural cavity (and lung surrounded by 2 layers of simple squamous and the fluid filled pleural cavity)
What is the role of the diaphragm?
Diaphragm movement changes thoracic volume- controls breathing process- inspiration/expiration.
contracts on inhalation/inspiration to enlarge the thoracic cavity - creates a vacuum pulling air down the open airways.
How many lobes are there of the lung?
- 2
- 3
- 4
- 5
- 6
5 lobes
Label
Which articulation can you palpate?
Describe its location.
The jugular notch -a large, visible dip in between the neck in humans → between the clavicles, and above the manubrium of the sternum.
What is the transthoracic plane?
An imaginary horizontal plane used to divide the mediastinum into the superior mediastinum and the inferior mediastinum. Inferior part of the aorta, where trachea bifurcates into two bronchi.
Horizontally travels through the sternal angle and the area between the T4 and T5 thoracic vertebrae.
How many nerves are in the thoracic spine?
What are the main nerves associated with the thorax?
12 thoracic spine nerves. Somatic nervous control-
- Phrenic nerve travels anterior to root of lung-originates from anterior rami of C3, C4 and C5 provides motor and sensory innervation.
- Vagus nerve travels posterior- passes through neck and thorax to the abdomen. It is a cranial nerve carrying parasympathetic supply to organs.
A) What direction do the muscles of the thoracic cage run?
B) What intercostal muscles have fibres that run antero-inferiorly?
- 90 degree like superficial abdominal muscles
- External intercostals
What do the intercostal spaces contain?
- x3 intercostal muscle groups- external, internal and innermost
- Intercostal nerves, arteries, veins (at intercostal groove)
- Pleura
What opening of the diaphragm does the vagus nerve pass through?
Oesophegeal hiatus
What is the pleura made up of? x2 layers
What are each layer of the pleural cavity separated by?
- Inner layer (visceral) that wraps around the lungs and is stuck to them.
- The outer layer (parietal) lines the ribs, diaphragm and mediastinum.
Serous layer -simple squamous epithelium, with serous fluid in between- with a negative pressure.
What is the role of the pleura?
A thin layer of tissue (visceral inner and parietal outer) that covers the lungs and lines the interior walls of the chest cavity. It protects and cushions the lungs.
The tissue secretes a small amount of serous fluid that acts as a lubricant allowing the lungs to move in the chest cavity while breathing.
What are the main differences between the two layers of pleura including innervation, location, role?
Parietal- outer layer- innervated by costal nerves (somatic sensory fibres)-good localisation of pain. Lines the boundaries of the cavity- costal thoracic wall, diaphragm and mediastinum.
Visceral- inner layer- innervated by visceral fibres- poor localisation of pain. Lines the surface of the lung itself
How many lobes does the left and right lung contain?
Right- 3
Left -2
Label
If a patient were to inhale something- where would it end up? Why?
In their right lung - lesser angle of convergence (more vertically relative to the hilum) and the diameter, larger
What are the types of movements the thorax allows for?
Pump Handle: superior and anterior movement of sternum- anterior posterior expansion.
Bucket handle: elevation and lateral - expansion
Define inspiration, what are the primary and secondary muscles involved?
The increase in volume in the the thoracic area by breathing in air.
- Diaphragm- primary
- Scalene muscles- of neck
- sternocleidmastoid
- external intercostals
What are the accessory muscles involved in expiration? For passive recoil of lungs
- Abdominal wall muscles
- Internal intercostals
- Passive recoil of lungs
How many synovial joints does a typical rib (2-9) have with vertebrae?
3.
Whereas ribs 1, 10-12 articulate with just 1.
What happens if the pleura is damaged?
Lungs collapse
Label
What is the hilum of the lungs?
The point of entry on the lungs for bronchi, blood vessels and nerves, (pulmonary arteries-off right ventricle and veins-to left atrium)
**In Embryonic hearts what are the two ways that you can avoid pulmonary circulation
- Foramen ovali allows for blood to move from right atria to left atria- becomes Fossa Ovalis after birth
- Ductus artisosis (connects the aorta and left pulmonary artery) - Becomes the ligamentum arteriosum
What endocrine gland is at the level of the sternal angle?
Thymus - innervated by phenic nerve and internal thoracic arteries
Arteries and nerves that pass anterior and posterior medial plane of the thorax (lungs)*
Phrenic nerve and internal thoracic arteries run anterior
vagus nerve and aorta run posterior
What is happening here?
Myocardial hypertrophy
What is the term for what is shown in this image? And the key structures?
Sternal angle- Angle of Louis- Located at T4, T5 /Rib 2. Found at the articulation between manubrium and body of sternum.
Key structures:
- arch of aorta
- bifurcation of the trachea into bronchia
- emergence of pulmonary trunk
- superior vena cava