Week 5 Lungs and Trachea

Question 1

What are the lungs?

Answer 1

Vital organs of respiration

main function is to oxygenate blood

Question 2

What seperates the two lungs?

Answer 2

the heart, great vessels and other viscera in the mediastinum

Question 3

What is the Pleura?

Answer 3

Connective tissue that forms a closed sac called the pleural sac

Question 4

What are the layers of the pleura?

Answer 4

Outer parietal layer (lines the thoracic cage, diaphragm and media stinum

Inner visceral layer:
Lines the lungs

Thin layer exists between the two

Question 5

Where do the two layers of pleura become continuous with each other?

Answer 5

at the root of the lung

Question 6

What defines the right lung from the left?

Answer 6

heavier
Larger
shorter (right dome of diapragm sits higher)
wider (heart bulging on left)
Horizontal fissure

Question 7

What defines the left lung from the right?

Answer 7

Has a deep cardiac notch on the superior lobe of the left lung

Question 8

What are lung fissures

Answer 8

lungs are divided into lobes by fissures
They are grooves on the surface of an organmarking it into divisions
They extend from the surface of the lungs to the hilum, sometimes not complete

Question 9

How many lobes does the left lung have?

Answer 9

two

Question 10

How many lobes does the right lung have?

Answer 10

three

Question 11

How are the lobes of the lungs divided further into segments?

Answer 11

by the divisions of the bronchi that supply them

Question 12

What are the lungs covered in?

Answer 12

Cervical pleura

Question 13

How many surfaces of the lungs are there and what are they?

Answer 13

Costal surface (adjacent to sternum,costal cartilages and ribs)
Mediastinal surface (relates to the mediastinum and vertebrae and includes the hilum)
Diaphragmatic surface (rests on the convex dome of the diaphragm)

Question 14

where does the costal surface lie? What else constitutes the costal surface?

Answer 14

adjacent to the sternum, costal cartilages and ribs
it is large, smooth and convex
separates the ribs from the costal cartilages and intercostal muscles by pleura
posteriorly it relates to the thoracic vertebrae

Question 15

Where does the mediastinal surface lie? What else constitutes to this surface?

Answer 15

Relates to the mediastinum containing the the heart and the pericardium
has a pericardial cavity which is deeper in the left lung
is the location of the hilum and the root of the lung as well as pleural sleeve covering
it is the point at which the following structures leave and enter the lung:
main bronchus
pulmonary vessels
bronchial vessels
lymphatic vessels
nerves

Question 16

How is the root of the lung formed?

Answer 16

by the following structures that pass through the hilum;
main bronchus
pulmonary vessels
bronchial vessels
lymphatic vessels
nerves

the root of the lung is also enclosed in a pleural sleeve

Question 17

What structures are found on the mediastinal surface?

Answer 17

groove for the oesophagus
Cardiac impression (for heart)

Question 18

difference in mediastinal surface in right and left lung?

Answer 18

Left has a reater cardiac impression
left has a prominant continuous groove for the aortic arch and descending thoracic aorta
also has a smaller groove for the oesophagus

Question 19

details about the diaphragmatic surface?

Answer 19

Is concave
forms the base of the lung
rests on the dome of the diaphragm
has a deeper concavity due to the liver

Question 20

How many lung borders are there and what are they called?

Answer 20

3;
Anterior
inferior
posterior

Question 21

What forms the anterior border? What does it overlap?

Answer 21

The costal and mediastinal surfaces anteriorly

Overlaps the heart

Question 22

What forms the inferior border?

Answer 22

Circumscribes the diaphragmatic surface of the lung, separates this durface from the mediastinal and costal surfaces

Question 23

What forms the posterior border? Where does it lie?

Answer 23

where the costal and mediastinal surfaces meet posteriorlrly

lies either side of the thoracic vertebral column

Question 24

What is the arterial supply to the lung?

Answer 24

Left and right pulmonary arteries (oxygenate deoxygenated blood and contribute to the root of the lung)
These give off their first branch to the superior lobe before entering the hilum
Within the lung they divide further into lobar and segmental branches
arteries and bronchi are paired in the lungs

Question 25

What is the venous supply to the lungs?

Answer 25

Pulmonary veins Carry oxygenated blood to the left atrium of the heart from the lungs run independently from the arteries

Question 26

Bronchial arteries:

Answer 26

Supply the structures that comprise the root of the lung, the supporting tissues and pleura

Question 27

Where do the left bronchial arteries arise?

Answer 27

From the thoracic aorta (usually 2)

Question 28

Where does the right bronchial artery arise?

Answer 28

from either; the thoracic aorta the superior posterior intercostal artery the common trunk with left superior bronchial artery

Question 29

What is the function of the bronchial veins?

Answer 29

Drain part of the blood supplied to the lungs by the bronchial arteries Right by azygos veins Left by accessory azygos vein

Question 30

Nerve supply to the lungs?

Answer 30

Parasympathetic: Vagus Sympathetic: T1-T6 by cardiopulmonary splanchnic nerves

Question 31

Where are the lower borders of the lungs found anteriorly, laterally (within the mid axillary line) and posteriorly?

Answer 31

``` Anteriorly (midclavicular line): 6th rib Laterally (midaxillary line): 8th rib Posteriorly: 10th rib (the pleural sits 2 spaces lower) ```

Question 32

Where does the hilum sit?

Answer 32

behind 3rd and 4th costal cartilages at the sternal margins | level of T5-T7 vertebrae

Question 33

Where are the oblique fissures?

Answer 33

Fissures formed by the line from the Spinous process of T3 to T6 rib in the mid clavicular line

Question 34

Where are the Horizontal fissures?

Answer 34

found on the right 4th costal cartilage, meets the oblique fissure in the mid axillary line

Question 35

Where is the trachea?

Answer 35

Extends from the larynx into the thoraxwhere it divides into left and right main bronchi Inferior end of the larynx (C6 just below the cricoid cartilage) to the angle of Louis (T4-T5) IV disc

Question 36

What is the function of the trachea? How long is it?

Answer 36

Is a passage for air to the lungs 10cm long, may lengthen to 15cm during inspiration

Question 37

What is the trachea?

Answer 37

A large section of hyaline cartilaginous tube which is supported by incomplete cartilagenous rings (tracheal rings)

Question 38

Where does the trachea divide into left and right bronchi?

Answer 38

At the transverse thoracic plane

Question 39

What sits in relation to the trachea?

Answer 39

``` Laterally: Common carotid arteries Brachiocephallic trunk (on the right) Anteriorly: isthmus of the thyroid gland inferior thyroid veins Posteriorly: oesophagus ```

Question 40

What epithelium does the trachea have?

Answer 40

Pseudostratified columnar ciliated epithelium

Question 41

What is the blood supply to the trachea?

Answer 41

Inferior thyroid arteries bronchial arteries (these anastomose at the tracheal wall) Veins drain into the inferior thyroid plexus (left at the braciocephallic vein)

Question 42

Where do the main bronchi run?

Answer 42

Pass inferomlaterally from the bifurcation of the trachea to the hila of each lung

Question 43

What to the bronchi contain?

Answer 43

c shaped hyaline cartilaginous rings

Question 44

Right main bronchus

Answer 44

is wider, shorter and runs more vertically than the left and passes directly to the lung

Question 45

Left main bronchus

Answer 45

passes inferolaterally passes inferior to the arch of the aorta anterior to the oesophagus and thoracic aorta then passes into the hilum of the lung

Question 46

What happens to the bronchi when they enter the hilum

Answer 46

They branch to form the bronchial tree

Question 47

What do the main bronchi branch into?

Answer 47

Lobar (or secondary) bronchi

Question 48

How many lobar bronchi are there?

Answer 48

5: 2 on the left 3 on the right (each supplies the corresponding lobe)

Question 49

What do lobar bronchi divide into?

Answer 49

``` segmental bronchi (pyramidal in shape, separated by ajoining segments by connective tissue) Each segment is supplied independently by a tertiary bronchus and artery ```

Question 50

What do segmental bronchi divide into?

Answer 50

Terminal bronchioles

Question 51

What do terminal bronchioles divide into?

Answer 51

Respiratory bronchioles

Question 52

What do respiratory bronchioles give off?

Answer 52

2-5 alveolar ducts which give rise to 5-6 alveolar sacs

Question 53

What are all the segments of the bronchi?

Answer 53

``` Main bronchus (or primary) Lobar bronchus Segmental bronchus Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveolar sac Alveoli ```

Question 54

What is the arterial supply to the trachea

Answer 54

Bronchial arteries (usually 3, 2 on left and 1 on right) Left bronchial arteries arise from the left aspect of the thoracic aorta Right bronchial arteries arise off either; Thoracic aorta superior posterior intercostal artery common trunk with the left superior lobal bronchial artery

Question 55

Bronchial veins

Answer 55

Are a superficial system Drain the hila region and visceral pleura drain into the azygos vein on the right Drain into the accessory azygos on the left deep veins drain into a main pulmonary vein or directly into the left atrium