thorax Flashcards
what does the thorax include?
sternum, costal cartilages, ribs, thoracic vertebrae, structures they enclose
what structures are at the top and bottom of the thorax?
superior thoracic aperture and inferior thoracic aperture
the thorax is split into 3 compartments, what are they?
left pleural cavity, right pleural cavity and mediastinum
what is the bone running down the centre of the chest called?
the sternum
what does the sternum contain?
manibrium, sternum, xiphoid process
what holds the chest together?
costal cartilage
what is the large dip between the neck and collar bone known as?
jugular notch
what are ribs 1-7 classified as?
true ribs
what are ribs 8-10 classified as?
false ribs
what are ribs 11-12 classified as?
floating ribs
what is the main function of ribs?
respiration
what is the name for the central compartment t of the thoracic cavity (excluding lungs)?
mediastinum
the mediastinum is sub categorised into 2 sections, what are these?
superior and inferior mediastinum
the inferior mediastinum is sub categorised into 3 sections, what are these?
anterior, middle and posterior
what structures are contained within the superior mediastinum?
great vessels, phrenic and vagus nerves, sympathetic trunk, part of thymus
what structures are contained within the anterior mediastinum?
fat and some thymus
what structures are contained within the middle mediastinum?
heart
what structures are contained within the posterior mediastinum?
descending thoracic aorta, hemiazygous veins, thoracic duct, oesophagus, vagus and splanchnic nerves
what is the 1st branch of the aorta?
coronary arteries
what do the left and right brachiocephalic veins do?
return blood to superior vena cava
what does the brachiocephalic artery divide into?
carotid and subclavian arteries
which vein drains head and neck?
internal jugular vein
which arteries supply the arms?
subclavian
which vein drains pulmonary trunk and breast tissue?
internal thoracic vein
which structure surround the heart and holds everything in place?
pericardium
the vagus nerve branches in the thorax, where does the left branch supply?
gut
what does the trachea divide into?
2 principle bronchi
where do the diaphragm muscle fibres arise from and converge towards?
arise radially from the costal margin and converge to insert into central tendon
the muscle of the diaphragm us higher on what side and why?
right - position of liver beneath
which type of muscle does the diaphragm consist of?
skeletal
which nerve supplies the diaphragm?
phrenic (cervival nerve 3, 4 and 5)
what happens to the diaphragm muscle during inspiration?
muscle flattens to increase capacity of thoracic cavity
what happens to the diaphragm muscle during expiration?
diaphragm returns to dome shape
fold in the diaphragm enclose what?
oesophagus and inferior vena cava
what happens to intra-abdominal pressure during contraction?
increased
what happens to thoracic pressure during contraction?
decreased
what does the thoracic cage consist of ?
12 ribs, manibrium, sternum and xiphoid process
what structure is used for palpitations of trachea to assess position?
jugular notch
where is the manubriosternal joint?
2nd rib
internal thoracic arteries are used for what clinical procedure?
coronary artery bypass
what is the function of connective tissue in the mediastinum?
allow cushioning and small degree of movement
why are there no valves in the vena cava?
blood falls in the direction of gravity
how many valves are in the aortic valve
3
where is the aortic sinus?
above aortic valve
what do coronary arteries arise from?
aortic sinus
when do aortic valves close?
ventricular diastole
what may the right av valve and left av valve be known as?
right - tricuspid valves
left - bicuspid
when do tricuspid valves close?
ventricular systole
what are valves kept in place by?
chordae tendinae holding valves vie papillary muscles
what is the name for an abnormal heart sound?
murmur
how many coronary arteries are there?
2
what is unique about coronary arteries?
they are end arteries
what would occur if coronary arteries were completely occluded?
myocardial infarction
what is the function of coronary arteries?
supply heart with oxygenated blood
how much bigger is the left ventricle compared to the the right?
3x
what kind of artery is the aorta?
elastic
what is the name for the prominence of the aorta as it changes direction in the chest?
aortic knuckle
why does the aorta not collapse during ventricular systole?
elastic recoil
what branches of the aorta pass into the neck?
brachiocephalic trunk, left common artery and left subclavian artery
what kind of innervation does the phrenic nerve provide to the diaphragm?
muscular - diaphragm
sensory - fibrous pericardium and peritoneum
what is the function of the arterial system?
deliver oxygenated blood round body
what are the 3 main types of vessel in arterial system?
elastic, muscular and arterioles
give examples of elastic arteries?
aorta, common carotid, subclavian, pulmonary
give examples of muscular arteries?
radial femoral, coronary, cerebral
what is the function of the venous system?
collecting system
what is the structural difference of veins compared to arteries?
veins have less elastic and muscle in their walls
