Thorax Flashcards
The thorax is a region of the trunk, what does it include?
- Sternum
- Costal cartilages (bars of hyaline cartilage connected to the ribs
- Ribs
- Thoracic vertebrae
- Structures they enclose
What shape is the thorax?
Cone shaped
What is the superior thoracic aperture?
- The upper chest opening
- At the root of the neck and in continuity with the neck
What is the inferior thoracic aperture?
- The skeletal muscle at the bottom of the thorax
- Also known as the thoracic outlet which is closed by the diaphragm
What are the 3 compartments of the thorax?
- Right pleural cavity
- Left pleural cavity
- Mediastinum
What is the jugular notch?
A notch on the manubrium
What are the great vessels located in the thorax?
- Venae cava
- Pulmonary trunk and main branches
- Pulmonary veins
- Aorta
What is the first branch of the aorta?
Coronary arteries
What vessels come off of the arch of the aorta?
2 on left side which are the left common carotid and the left subclavian
1 on the right side which is called the brachiocephalic trunk, which splits into 2: the right common carotid and the right subclavian
The internal carotid artery supplies what % of blood to the brain?
80%
What is the function of the pulmonary trunk?
Takes deoxygenated blood back to the lungs
Where does the inferior vena cava drain blood from?
Everywhere below the level of the heart
Where does the superior vena cava drain blood from?
Everywhere above the level of the heart
What do the R and L pulmonary veins take blood to?
Take oxygenated blood back to the heart
Where does the internal jugular vein drain blood from?
Drains facial structures and the brain
The diaphragm is a musculotendinous structure. What does this mean?
It is made of muscles and tendons
In the diaphragm, muscle fibres arise radially from the costal margins and converge to inset into the central tendon. What are the costal margins and the central tendon?
Costal margins - Cartilage along the edge of the 8th through to the 10th ribs in the middle of the chest. Marks the lower region of the chest and the location of the diaphragm
Central tendon - a broad connective tissue sheet that forms the diaphragm. It is composed of interlacing fibres that arise from the lumbar vertebrae, the costal margin and the xiphoid process of the sternum
The muscle of the diaphragm is ‘dome-shaped’ on each side but is higher on the right than the left. Why?
Due to the position of the liver beneath
What kind of muscle is the diaphragm?
Skeletal muscle under voluntary and involuntary control
Which nerve is the diaphragm supplied by?
The phrenic nerve - Cervical 3,4 and 5
What is referred pain?
Pathology in one part of the body but pain is shown in another part of the body
What types of fibres does the phrenic nerve contain?
- Motor and sensory
What happens to the shape of the diaphragm on inspiration and expiration?
- On inspiration, the muscle flattens to increase the capacity of the thoracic cavity
- On expiration, the diaphragm returns to its ‘dome-shape’
