Lecture 1: Lungs and the Pleura Flashcards
which layer does the respiratory system develop from and when
4-6 weeks from endoderm
what is the process of development of the respiratory system
- endodermal outpouches form lung buds and bronchial buds
- rapid division of the airways
- lungs push out against thoracic cavity, taking visceral pleura with them
what are the pleurae of the lung
innermost is visceral
outermost is parietal
what are the parts of the parietal pleura and what are they innervated by
- cervical, first intercostal nerve
- costal, intercostal nerves
- mediastinal, phrenic nerve
- diaphragmatic, lower intercostal and phrenic nerves
what happens in pneumothorax or haemothorax
surface tension between pleural layers is lost and the lung can collapse
what are the pleural cavity recesses
- costomediastinal recess on left lung, where heart sits
- costodiaphragmatic recess
what are the visceral pleura innervated by
autonomic (sympathetic and parasympathetic) from pulmonary plexuses
features of left lung
- 2 lobes
- oblique fissure
- cardiac notch
- lingula
features of right lung
- 3 lobes
- oblique and horizontal fissures
what are the surfaces of the lung
- costal
- mediastinal
- diaphragmatic
features of hilum
- visceral pleura folds back in on itself to form parietal pleura
- pulmonary ligament which allows structures of hilum to move with lung movement
components of the hilum
- bronchi (most posterior)
- pulmonary arteries (most superior) and veins (most inferior)
- bronchial arteries and veins
- pulmonary plexus
- lymph vessels and nodes
where do the bronchial arteries descend from
left: descending aorta
right: intercostal arteries
where do the bronchial veins terminate
Azygos system of veins
what are the lungs innervated by
- sympathetic from sympathetic trunk
- parasympathetic from vagus
effects of sympathetic and parasympathetic nerves on lungs
sympathetic - dilates bronchial muscles - constricts pulmonary vasculature parasympathetic - constricts bronchial muscles - dilates pulmonary vasculature
what are the main lymph nodes
- bronchopulmonary (hilar nodes)
- tracheobronchial
- paratracheal
which vertebrae does the trachea run from
C6 to T4/5
what is the trachea made up of
- anteriorly: c-shaped cartilage rings
- posteriorly: trachealis muscle
where does the trachealis muscle bifurcate
level of sternal angle, T4/5
what is the cartilage where the trachea bifurcates called
carina
how many bronchopulmonary segments are there
10 in right lung, 8-10 in left
what are the types of bronchioles
- terminal, just conduits with no gas exchange occurring
- respiratory, have alveolar duct ended in alveolar sac surrounded by alveoli
what are the types of alveolar cells
Type 1, 95%
Type 2, 5% secrete pulmonary surfactant which prevents alveoli from collapsing due to surface tension
