Lecture 1: Lungs and the Pleura

Question 1

which layer does the respiratory system develop from and when

Answer 1

4-6 weeks from endoderm

Question 2

what is the process of development of the respiratory system

Answer 2

• endodermal outpouches form lung buds and bronchial buds
• rapid division of the airways
• lungs push out against thoracic cavity, taking visceral pleura with them

Question 3

what are the pleurae of the lung

Answer 3

innermost is visceral

outermost is parietal

Question 4

what are the parts of the parietal pleura and what are they innervated by

Answer 4

• cervical, first intercostal nerve
• costal, intercostal nerves
• mediastinal, phrenic nerve
• diaphragmatic, lower intercostal and phrenic nerves

Question 5

what happens in pneumothorax or haemothorax

Answer 5

surface tension between pleural layers is lost and the lung can collapse

Question 6

what are the pleural cavity recesses

Answer 6

• costomediastinal recess on left lung, where heart sits

- costodiaphragmatic recess

Question 7

what are the visceral pleura innervated by

Answer 7

autonomic (sympathetic and parasympathetic) from pulmonary plexuses

Question 8

features of left lung

Answer 8

• 2 lobes
• oblique fissure
• cardiac notch
• lingula

Question 9

features of right lung

Answer 9

• 3 lobes

- oblique and horizontal fissures

Question 10

what are the surfaces of the lung

Answer 10

• costal
• mediastinal
• diaphragmatic

Question 11

features of hilum

Answer 11

• visceral pleura folds back in on itself to form parietal pleura
• pulmonary ligament which allows structures of hilum to move with lung movement

Question 12

components of the hilum

Answer 12

• bronchi (most posterior)
• pulmonary arteries (most superior) and veins (most inferior)
• bronchial arteries and veins
• pulmonary plexus
• lymph vessels and nodes

Question 13

where do the bronchial arteries descend from

Answer 13

left: descending aorta
right: intercostal arteries

Question 14

where do the bronchial veins terminate

Answer 14

Azygos system of veins

Question 15

what are the lungs innervated by

Answer 15

• sympathetic from sympathetic trunk

- parasympathetic from vagus

Question 16

effects of sympathetic and parasympathetic nerves on lungs

Answer 16

sympathetic
- dilates bronchial muscles
- constricts pulmonary vasculature
parasympathetic
- constricts bronchial muscles
- dilates pulmonary vasculature

Question 17

what are the main lymph nodes

Answer 17

• bronchopulmonary (hilar nodes)
• tracheobronchial
• paratracheal

Question 18

which vertebrae does the trachea run from

Answer 18

C6 to T4/5

Question 19

what is the trachea made up of

Answer 19

• anteriorly: c-shaped cartilage rings

- posteriorly: trachealis muscle

Question 20

where does the trachealis muscle bifurcate

Answer 20

level of sternal angle, T4/5

Question 21

what is the cartilage where the trachea bifurcates called

Answer 21

carina

Question 22

how many bronchopulmonary segments are there

Answer 22

10 in right lung, 8-10 in left

Question 23

what are the types of bronchioles

Answer 23

• terminal, just conduits with no gas exchange occurring

- respiratory, have alveolar duct ended in alveolar sac surrounded by alveoli

Question 24

what are the types of alveolar cells

Answer 24

Type 1, 95%

Type 2, 5% secrete pulmonary surfactant which prevents alveoli from collapsing due to surface tension