The Thorax Flashcards
What is the thorax?
Area between the neck and abdomen
What is the framework of the thorax?
Bones, muscles, cartilage
What is the main functions of the thorax?
- Respiration
- Protection of vital organs of chest
- Pathways
What is the thoracic cage formed by?
- Sternum and costal cartilages (anterior)
- Ribs and inter coastal spaces
- Vertebral column (posterior)
How many thoracic vertebrae are there?
12
What are the parts of the sternum?
- Manubrium
- Body
- Xiphoid
What is the manubrium?
- “Handle”
- Superior part
- Square shaped
What is the body of the sternum?
- Long and narrow
- Ribs attach to the body lateral
A hinge joint is located where in the sternum and why?
It is located between the body and the manubrium and used for breathing
What is the Xiphoid?
Smaller inferior tip
What is the suprasternal or jugular notch
- Central depression
- Located on the superior surface of the manubrium
What is the sternal angle?
- Hinge joint
- Palpable ridge approximately 5 cm below the notch
- Level of aortic arch
Where is the Xiphoid process located ?
Where the right and left costal margins meet
What are the true ribs? And how many are their?
True ribs are connected directly with the sternum. There are seven of them
What are the false ribs? How many are there?
There are 5 false ribs and they are indirectly connected with the sternum.
What are the two sections of the false ribs?
- Ribs 8-10 that has costal cartilage which articulate with each rib above
- Ribs 11-12 which are floating ribs
The thoracic cavity is subdivided into how many compartments? What are they?
Three compartments
1. Two pleural spaces
2. Mediastinum
What is the thoracic inlet?
- Superior thoracic aperture
- Small yet very important
What are the numerous structures that pass through the thoracic inlet?
- Trachea and esophagus
- Arteries and veins
- Nerves and lymph
- Apex of lungs
What is the thoracic outlet?
- Larger then inlet
- Diaphragm forms the partition between the thorax and the abdomen
What is the diaphragm?
- Partition between thoracic and abdominal
- Upward arching dome
What attaches the diaphragm to the lumbar or spine?
Crura
Where are the openings in the diaphragm?
- Aorta at T12
- Esophagus at T10
- IVC at T8
What are the Anterior muscles of the chest?
Pectoralis muscles
What are the posterior muscles of the chest?
- Trapezius and latissimus (superficial)
- Rhomboid and elevator scapulae (deep to trapezium muscle)
What are the intercostal muscles?
- Located between the ribs
- Allow for expansion/ contractions during respiration
How many layers of the intercostal muscles are there?
Three layers
1. External
2. Internal
3. Innermost
What is the apex of the lungs?
Domed, superior portion that projects above the inlet
What is the base of the lungs?
- Inferior aspect
- Broad
- Rest on diaphragm; extends lower in the back and sides than in the front
What is the hilum of the lungs?
Depression on the mediastinal surface where structures enter and exit.
What are the structures of the hilum?
- Primary bronchi
- Pulmonary blood vessels
- Lymph nodes
- Nerves
What is the primary bronchi?
Right and left
What is the secondary bronchi?
- Branch from the primary bronchi
- One branch per lobe of lung
Right lung = 3; Left lung = 2
What is the tertiary bronchi?
- Bronchial tree
- Alveoli
What is the alveoli?
Functional unit of the lung; oxygen and carbon dioxide exchange
What is the pleura?
A double membrane sac which encloses the lungs
What is the visceral layer of the pleura?
Inner layer that adheres directly to the lung surface
What is the parietal layer of the pleura?
- Lines the wall of the thoracic cavity
- Adheres to the upper surface of diaphragm
What are the pleural cavities?
- Right and left spaces of the thoracic cavity
- Situated lateral to the mediastinum
- Fluid or air can collect in these cavities
What is a pleural effusion?
Fluid in the cavity
What is a pneumothorax?
Air in the cavity
What is the function of the thymus gland?
Immunity
What is the location of the thymus gland?
- Anterior to the great vessels
- Posterior to the manubrium
What is the size of the thymus gland?
- Largest during childhood
- Atrophies with age and almost disappears
What is the thymus gland?
Bilobed structure