the thorax Flashcards
what is included in the thorax
sternum
costal cartilages
ribs
thoracic vertebrae
structures enclosed
how can the shape of the thorax be described
irregular
what are the two apertures of the thorax
the superior and inferior thoracic apertures.
what is the superior thoracic aperture
the opening at the root of the neck that is continuous with the neck
what is the inferior thoracic aperture
the opening which is closed by the diaphragm
what are the three compartments of the thorax
right and left pleural cavities and the mediastinum
what is found in the pleural cavities
the lungs
what is at the top of the thorax
- first thoracic vertebrae
- first rib
- manubrium of the sternum
what is the jugular notch
the area where the trachea can be felt, and can make deviation clear, indicating any pathologies in the lungs like collapse or fluid
what are the pectoral girdle
bones which connect to the arm on each side
what is included in the pectoral girdle
clavicle and scapula
what is the clavicle
collar bone
what is the scapula
shoulder blade
what does the sternal angle show
where the second rib is
what is the sternal angle useful for
counting ribs inferiorly and laterally for chest drain insertion
what is effusion
fluid in the pneumothorax
where is the costochondral joint
the joint between the costal cartilages and the ribs
how many true ribs are there
7
what are the true ribs
1-7, as their costal cartilage links directly with the sternum
what are the false ribs
8-10
how many false ribs are there
3
why are they called false ribs
their costal cartilages are attached to the cartilage of the higher rib
what are the floating ribs
the vertebral ribs, 11 and 12, that are short and not attached to the sternum at all. instead, their costal cartilage terminates within the musculature of the lateral abdominal wall
what is the intercostal space
the space between the ribs
what is the intervertebral discs
the discs between the vertebrae
what is the mediastinum
the central portion of the thoracic cavity, surrounded by the left and right pleural sacs
what can the mediastinum be divided into
superior, anterior, middle, posterior
what is found in the upper portion of the superior mediastinum
first thoracic vertebrae
what is found in the lower portion of the superior mediastinum
sternal angle, which is the landmark for the second rib
what are the regions of the inferior mediastinum
anterior
middle
posterior
what is found in the anterior mediastinum
the fat and thymus gland
what is found in the middle mediastinum
the heart
what is found in the posterior mediastinum
the aorta and the oesophagus
what is the common carotid artery responsible for
blood supply to the head and neck
what are the great vessels
- venae cavae
- pulmonary trunk and its branches
- pulmonary veins
- aorta
what do the superior and inferior venae cavae do
drain venous blood from the head and neck and above the level of the heart, and below the level of the heart. both enter the right atrium of the heart
where does the pulmonary trunk exit the heart
the right ventricle
what does the internal carotid artery do
supply 80% of brain blood supply
describe the blood supply of the brain
80% internal carotid
20% vertebral artery
what does the external carotid artery supply
face
tongue
head external to the brain
what are the first main branches of the aorta
the coronary arteries
where is the brachiocephalic trunk
right side of the body
what does the brachiocephalic trunk give rise to
the right subclavian and the common carotid arteries
which blood is found in the pulmonary arteries
deoxygenated blood
what do the right and left internal jugular veins drain
the head and neck, including the brain down to join the right and left subclavian veins
what do the left and right subclavian veins drain
the left and upper right limbs
what forms the brachiocephalic veins on the left and right side
the internal jugular and subclavians
what does the superior vena cava drain
everything above the level of the heart
what forms the superior vena cava
the unity of the left and right brachiocephalic veins
what blood is found in the pulmonary veins
oxygenated blood
what is the longus colli
a paired muscle found on the anterior vertebral column that results in contralateral contraction and both contracting results in neck flexion for bending down
what is the largest lymphatic drainage
the thoracic duct
where does the sympathetic trunk arise from
the first thoracic vertebrae to the second lower lumbar vetebrae
what does the sympathetic trunk do
increase heart rate and breathing and take blood away from the gut
what type of artery is the aorta
elastic
what is the main artery of the body
the aorta
which chamber does the aortic arch arise from
the left ventricle
what is the rest and digest nerve
the vagus nerve
what does the vagus nerve do
increase gut motility, reduce heart rate and breathing rate
describe the hemiazygous vein
comes from the left lumbar ascending vein
it drains from the posterior trunk muscles and skin into the azygous
describe the accessory hemiazygous vein
superior hemiazygous vein coursing through the posterior mediastinum, receives tributaries along the way
what are the tributaries of the accessory hemiazygous vein
fifth, sixth, seventh and eighth posterior intercostal veins, left superior intercostal vein, and the left bronchial veins
describe the route of the accessory hemiazygous vein
usually crosses the midline and terminates by draining into the azygous vein at the level of the seventh thoracic vertebrae
describe the greater splanchnic nerve
a paired visceral nerve carrying autonomic fibres and sensory fibres from internal organs to the abdominal organs. all carry sympathetic fibres
which nerves does the greater splanchnic receive
nerves from the fifth to the eighth vertebrae
function of the internal thoracic vessels
supplies and drains the skin and muscles of the anterior aspect of the thoracic cage and the superior aspect of the abdominal wall, typical ribs, breasts, parietal pleura, sternum, pericardium and the thymys
what is the left auricle
part of the left atrium
what does the phrenic nerve innervate
the diaphragm
what forms the phrenic nerve
cervical nerves 3-5
what is the recurrent laryngeal nerve
part of the vagus nerve innervating the muscles of the larynx and sensation to the larynx, found below the vocal folds
what is the cardiac plexus
this provides nerves to the heart
describe the diaphragm
a musculotendinous structure that is dome shaped on either side, but is higher on the right than on the left due to the position of the liver
where do the muscle fibres of the diaphragm arise from
the costal margins, converging to insert into the central tendon
what kind of muscle is the diaphragm
skeletal muscle
what supplies the diaphragm
the phrenic nerve
what does the phrenic nerve contain
motor and senosry fibres
what happens to the diaphragm as we inhale
the muscle flattens to increase capacity of the thoracic cavity
what happens to the diaphragm when we exhale
the diaphragm returns to its dome shape
describe the costodiaphragmatic recess
larger of the recesses found between the costal and diaphragmatic pleura of the right and left pleural cavities. provides space for the lungs to fill, but fluid can accumulate here
how is air expelled
relaxation of the diaphragm coupled with the elastic recoil of the lungs
what is the function of the ribcage
functions more for breathing than protection due to the spaces in between
describe the irregularity of the shape of the diaphragm
it is narrow at the top and wider at the bottom
do the lungs enter the neck
yes, up to the medial third of the clavicle
where is CPR undertaken
the xyphoid process of the sternum
why are the floating ribs risky
they can fracture and puncture organs like the spleen
why are the floating ribs so prone to trauma
because they do not join with the costal cartilages and the rest of the ribcage
what is referred pain
pathology on one side but pain felt on the other, because the nerves can get muddled and the brain gets confused
examples of referred pain
irritation of the gall bladder felt as shoulder tip pain
hip pathology felt as knee pain and vice versa
does the aorta pass through the diaphragm. explain your answer
no, it sits behind it. this prevents the lungs compressing the aorta during inhalation
describe the opening of the superior thoracic aperture
narrow, and open to be continuous with the neck
describe the opening of the inferior thoracic aperture
large, closed off by the diaphragm
describe the mediastinum
soft tissue partition, orientated longitudinally in a median sagittal position.
what is within the mediastinum
heart
oesophagus
trachea
major nerves
major systemic blood vessels
what separates the left and right pleural cavities
the mediastinum
are the pleural cavities completely separated from each other
yes
why do abnormal events in the root of the neck impact the lungs
the apex of the lung extends into the root of the neck
what machinery is necessary for breathing
diaphragm
thoracic wall
ribs
lungs
what passes through the mediastinum
oesophagus
vagus nerves
thoracic duct
what comprises the thoracic wall
- skeletal muscle
- 12 vertebrae
- 12 ribs on each side
- three layers of flat muscle
- sternum
what composes the distal end of each rib
costal cartilage
function of costal cartilage
compose the distal end of each rib to attach to the sternum. contributes to the elasticity and mobility of the wall
what seals the inferior thoracic aperture
musculotendinous diaphragm
what forms the central tendon
the conversion of the muscle fibres of the diaphragm
what lines the pleural cavities
mesothelial membrane called the pleura
what attaches each lung to the mediastinum
a root formed from the
- airway
- pulmonary blood vessels
- lymphatic tissues
- nerves
what is the axillary inlet
a gateway to the upper limb and lies on each side of the superior thoracic aperture. formed by the superior margin of the scapula, posteriorly, and the clavicle anteriorly
where does the oesphagus penetrate the diaphragm
the oesophageal hiatus. an opening to the left of the midline of VX
where do all preganglionic sympathetic nervous system come out
the spinal cord in the spinal nerves T1-L2
which spinal nerve do the preganglionic sympathetic fibres destined for the head leave from
T1
what is the major contribution to the phrenic nerves
C4 from the cervical plexus
describe the route taken by the phrenic nerves
vertically through the neck and superior thoracic aperture, and through the mediastinum to supply motor innervation to the entire diaphragm.
is the phrenic nerve in front or behind the lungs
in front
why is the root of the phrenic nerve so far from the diaphragm
the tissue that gives rise to the diaphragm originates to the ultimate location of the diaphragm, which is why its innervation has cervical origin
what are the muscles of the thorax
major and minor pectoralis, subclavius
