Anatomy of thorax Flashcards
What are the functions of the Thorax?
protection of vital organs
Facilitates respiratory movements
How many vertebrae and ribs are there?
12
What is the costal margin?
When ribs share costal cartilage T7-10
Why is T8-10 aka false ribs?
link together before attaching to sternum
What are T11-12 Ribs?
floating ribs
What sits between ribs?
intercostal muscles
What is neurovascular bundle?
ribs has own set of vessels/nerves between innermost and internal fibres
What are the 2 articulation attachments for the rib?
posterior vertebrae and sternum ( to sternum via costal cartilage)
What is sternum made up of ?
Manubrium
body
Xiphoid
What does the sterna angle do?
divide into inferior and superior thorax
What is the thoracic inlet?q
how thoracic cavity communicates with root of neck, into the thorax
T1 vertebra and superior border of manubrium
what pass through thoracic inlet?
esophagus
trachea
apices of lungs
What is the Thoracic Outlet?
how thoracic cavity communicates with abdomen
What are boundaries of thoracic outlet?
Anterior margin of T12
ribs 11/12
Costal margin
Xiphisternal joint - between xiphoid and mesosternum
What is the Diaphragm?
muscle that separates the thorax from abdomen
What muscle fibres does diaphragm have?
radiating fibres from central tendon and attach to costal margin and onto vertebrae
What does inspiration do?
diaphragm moves downwards so thoracic vol. increase
and pressure decreases
Why does diaphragm have apertures ?
to allow vessels, nerves and oesophagus to travel from thorax to enter abdomen
Where does Aorta travel in diaphragm
behind it at T12
Where does inferior vena cava travel?
central tendon at T8
Where does Oesophagus travel in diaphragm
at T10
What happens to diaphragm in inhalation ?
flattens
What happens to diaphragm in exhalation ?
Domed
What is the most Anterior out of the three main openings?
Inferior vena cava
What are the 3 layers to intercostal muscles?
External intercostal
Internal
innermost
What happens when external fibres contract?
pull rib up and out
What groove does ribs have?
Costal
How does innermost fibres run?
Same direction as internal
What do the upper ribs do?
increase Anterior-Posterior diameter, move up
What do Lower ribs do?
Increase Transverse diameter , move out
What happens when we breathe in?
- ribcage up and out
- increase distance between sternum and thoracic vertebrae
What does the Mediastinum midline region enclose?
heart, major vessels and nerves, trachea, oesophagus
What are the major vessels enclosed by mediastinum?
Brachiocephalic veins
superior vena cava
aorta arch
What are 2 pleural sacs lined with?
Visceral and Parietal pleura that create Pleural Sac
What is visceral layer attached to?
Lungs
What is parietal layer attached to?
Thoracic cavity
What is Pleural cavity?
Small space between visceral and parietal pleura
What does Serous Pleural Fluid do?
reduces friction
creates surface tension between layers
What does the right lung have?
3 LOBES- superior, middle and inferior
2 FISSURES- horizontal and oblique
What does left lung have
2 LOBES- Superior and inferior
1 Oblique fissure
What is the Hilum?
medial aspect of lung where vessels leave/enter
What is Pulmonary ligament?
Where 2 pleura’s connect together so movement within lung
What vessels in Hilum?
Pulmonary artery enters and Pulmonary Vein leaves
What are the divisions of Mediastinum?
plane via Sternal angle and lower border of T4
What are the subdivisions of Mediastinum?
Superior and Inferior Mediastinum
What is Inferior Mediastinum divided into?
Anterior, Middle and Posterior mediastinum
What does superior mediastinum house?
oesophagus, trachea and vessells
What does middle part of inferior mediastinum house
heart and pericardium
What does Posterior part of inferior mediastinum house
vessels, tubes and nerves
What does Superior Mediastinum house?
Arch of Aorta Thymus superior vena cava Brachiocephalic trunk left subclavian artery Left common carotid artery Trachea/ oesophagus
What does Anterior part of inferior mediastinum house
Thymus
What does Posterior part of inferior mediastinum house
Thoracic aorta
Azygos veins
Thoracic duct
Where does thoracic aorta originate ?
T4 and passes posteriorly to diaphragm
Where does Azygos vein?
at T12 w/ aorta and drains the right chest
