Respiration part 2 (A5) Flashcards
internal thoracic artery in relation to chest wall
run down the posterior aspect of the anterior chest wall
mediastinum
contains heart and great vessels
diaphragm description
skeletal muscle that forms floor of thorax/roof of abdomen, involved in VOLUNTARY control, sits slightly higher on right hand side as liver pulls it up slightly
visceral pleura
touches lung (around lung bud), continuous with parietal pleura
parietal pleura
touches chest wall, can be 2 types - diaphragmatic parietal pleura and mediastinal parietal pleura
pleural cavity
between lungs and chest wall, creates a vacuum, called a potential space as it is so small
how are lungs held to chest wall
pleural cavity holds lungs to chest wall and keeps them filled due to the surface tension created by the pleural fluid
costodiaphragmatic recess
extension of pleural cavities
vessels travelling to upper limb
subclavian artery/vein and nerves of the brachial plexus
position of internal thoracic artery and veins
travel down deep surface of anterior part of ribs
route of upper respiratory tract
nasal cavity/ nose or oral cavity/mouth -> larynx/voice box -> trachea/ windpipe -> 2 main bronchi/bronchus -> lungs
lung bud
pushes outwards from mediastinum in embryo and grows into lung pushing into pleural cavity (decreases in size)
hilum
/lung root contains main bronchus, pulmonary artery and two pulmonary veins (also pulmonary lymph nodes present- appear black due to carbon dioxide deposits)
what is the only vessel in the root of the lung that has cartilage within?
bronchus/ main bronchi (hyaline cartilage in walls)
surface markings on the medial aspect of right lung
from superior vena cava, and azygous vein
surface markings on medial aspect of left lung
due to aorta
phrenic nerves
combined anterior rami of cervical spinal nerves c3,4 and 5, found in the neck on the anterior surface of the scalenus anterior muscle and in the chest/thorax descending over the lateral aspects of the heart, supply motor and sensory fibres to the skeletal muscle of the diaphragm (C3,4,5 keep the diaphragm alive). pass through diaphragm then spread out on deep surface to innervate it
features of right lung
lung apex, superior lobe, horizontal fissure, middle lobe, oblique fissure, inferior lobe, base
features of left lung
lung apex, superior lobe, lingula (of superior lobe) oblique fissure, inferior lobe, base
where is the pleural fluid contained
within the pleural cavity/vacuum
mechanics of normal inspiration
diaphragm contracts and descends increasing vertical dimensions, intercostal muscles contract elevating ribs which increases A-P and lateral chest dimensions, chest walls pull the lungs outwards with them, causing pressure inside the lungs to drop creating negative pressure gradient and air flows into the lungs
why is normal quiet expiration described as passive
all muscles are relaxing, not contracting
accessory muscles of inspiration
pectoralis major and minor, sternocleidomastoid, scalene muscles (aid normal muscles of inspiration during forced inspiration eg. heavy exercise, high altitude, asthma etc, attached onto ribs/sternum and change dimensions of chest cavity increasing its size, therefore there is more room to breathe in more air)
mechanics of expiration
diaphragm relaxes and rises decreasing vertical chest dimensions, intercostal muscles relax lowering ribs decreasing A-P and lateral chest dimensions, elastic tissue of lungs recoil and air flows out of the lungs
accessory muscles of expiration
rectus abdominus (ab muscles) when they contract the diaphragm is actively pushed up into resting position by the compressed abdominus contents
carina
ridge between two main bronchi
cartilage of trachea
more C shaped than it is a full circle
lobar bronchi
one lobar bronchi per lobe of lung therefore the right lung has 3 and left lung only has 2
pneumothorax
air in pleural cavity, can be caused by an injury to the chest wall allowing air into the pleural cavity via a tear in the parietal pleura, or lung tissue may rupture causing release of air into the pleural cavity via tear in visceral pleura - both situations cause the vacuum to be lost and the lung collapses due to elastic recoil
where does the trachea bifurcate into the two main bronchi
at the level of the sternal angle
what is the most likely location to find an inhaled foreign body (if patient is in upright position when inhalation occurs)
lower lobe of right lung as it the right bronchus is wider, shorter and more verticle, if this is a possibility a chest radiograph/bronchoscopy can be carried out
