Thorax I - Lungs

Question 1

Thoracic Cavity

Answer 1

• divides into three subdivisions - two pulmonary cavities and teh mediastinum

Question 2

Mediastinum

Answer 2

• the middle componenent of the thoracic cavity (between the two pleural cavities)
• contains the heart, great vessels, and trachea

Question 3

Borders of the Mediastinum

Answer 3

Superior - superior thoracic aperture

Inferior - Diaphragm

Lateral - Pleural cavities and the lungs

Anterior - Sternum

Posterior - Thoracic vertebrae

Superior & Inferior portions divided by plane that passes through the sternal angle and the transverse thoracic plane (bw 4th and 5th thoracic vertebrae

Question 4

Pulmonary Cavities

Answer 4

• aka Pleural Cavities
• the lateral cavities of the thoracic cavities
• lined with pleura and contain the lungs

Question 5

Pleura

Answer 5

• serious membrane that lines the pulmonary cavities and forms the outer surface of the lungs

Question 6

Parietal Pleura

Answer 6

• the serous membrane that lines the pulmonary cavities

Question 7

Visceral Pleura

Answer 7

• the serous membrane that lines the surface of the lungs
• made up of a simple squamous epithelial membrane

Question 8

Pleural Cavity

Answer 8

• potential space between the parietal pleura and the visceral pleura
• contains only a slight amount of serous fluid

Question 9

Hilum

Answer 9

• the root of the lungs
• continuous with the pleura
• contains the primary bronchi and pulmonary arteries/veins

Question 10

Divisions of the Parietal Pleura

Answer 10

Costal Pleura

Cervical Pleura

Medial Pleura

Diaphragmatic Pleura

Question 11

Pleural Reflections

Answer 11

Transitions between pleural divisions

Question 12

Pleural Recesses

Answer 12

• potential spaces between parietal pleura

Examples: Costomediastinal Recesss, Costodiaphragmatic Recess

Question 13

Costodiaphragmatic Recess

Answer 13

• the inferior-most portion of the pleural cavity
• where the costal parietal pleura reflects to become diaphragmatic parietal pleura
• lung does not extend fully into this recess

Question 14

Oblique Fissure

Answer 14

• the fissure located in both lungs that extends diagonally

Right Lobe: divides middle lobe and lower lobe

Left Lobe: divides upper and lower lobe

Question 15

Horizontal Fissure

Answer 15

• aka minor fissure
• the fissure in the right lung that separates the upper and middle lobe

Question 16

Trachea

Answer 16

• windpipe
• tube that conveys air to and from the lungs
• contains C-shaped rings of catilage, smooth muscle, and connective tissue

Question 17

Trachea Bifurcation

Answer 17

• where the traches splits into the two main (primary) bronchi
• at the level of the T4/T5 intervertebral disc

Question 18

Carina

Answer 18

• the bifurcation ridge on the internal aspect of the trachea

Question 19

Main (Primary) Bronchi

Answer 19

• the first branches from the trachea, located where the trachea bifurcates (carina)
• at the level of the _sternal angl_e and T4/T5 vertebrae
• enters the lung at the hilum

Right Main Bronchus - more vertical

Question 20

Lobar (Secondary) Bronchi

Answer 20

• bronchal divisions from the main bronchi
• supply individual lobes
• named for the lobes they supply:

Upper Lobe Bronchus

Middle Lobe Bronchus

Lower Lobe Bronchus

Question 21

Segmental (Tertiary) Bronchi

Answer 21

• divisions after the lobar bronchi
• named by a number or segment name (i.e. apical segment bronchus)

Question 22

Intermediate Bronchus

Answer 22

• located in the right lobe
• after main bronchi, bronchi divide into Upper Lobe Bronchi and Intermediate Bronchus
• Intermediate Bronchus divides into Middle Lobe Bronchi and Lower Lobe Bronchi

Question 23

Superior Thoracic Aperture

Answer 23

• the superior boundary of the thoracic cavity
• an opening along the plane of the 1st rib
• the apex of the lungs extend above

Question 24

Diaphragm

Answer 24

• the inferior boundary of the the thoracic cavity
• separates the thorax from the abdomen

Question 25

Upper Lobes of the Lung

Answer 25

- located superior and anterior to the oblique fissure

Question 26

Lower Lobes of the Lung

Answer 26

- located inferior and posterior to the oblique fissure

Question 27

Middle Lobe of the Right Lung

Answer 27

- located lateral and anterior between the oblique and horizontal fissure

Question 28

Lung Apex

Answer 28

- extends several centimeters superior to the clavicle

Question 29

Surface Projections of the Lung and Pleura

Answer 29

Surface Projections of Lung: Ribs 6-8-10 Surface Projections of the Pleara: Ribs 8-10-12 (anterior-lateral-posterior)

Question 30

Division of the Respiratory Tree

Answer 30

Left Lung: Trachea (windpipe) → Main Bronchus → Lobar Bronchi (2) → Segmental Bronchi Right Lung: Trachea (windpipe) → Main Bronchus → Upper Lobar Bronchi (3) → Segmental Bronchi → Intermediate Bronchus → Middle and Lower Lobar Bronchi (2) → Segmental Bronchi

Question 31

**Pulmonary Arteries**

Answer 31

- carry deoxygenated blood from the right heart to the lungs - branches travel alongside the bronchi into each lung segment

Question 32

**Pulmonary Veins**

Answer 32

- carry oxygenated blood from lung capillaries to the left side of the heart - travel between adjacent lung segments receiving blood from both

Question 33

**Bronchial Arteries**

Answer 33

- supply the bronchial tree and lung with oxygenated blood

Question 34

**Lymphatic Drainage**

Answer 34

- from the lung and visceral pleura towards and through the hilum

Question 35

**Bronchopulmonary Nodes**

Answer 35

- lymph nodes clustered around lobar and main bronchi at the hilum

Question 36

**Tracheobronchial Nodes**

Answer 36

- lymph nodes that surround the bifurcation of the trachea at the carina

Question 37

Inspiration

Answer 37

- comes from contraction of diaphragm muscles - the diaphragm is flattened and moves inferiorly, aided by the intercostal muscles (elevate ribs laterally - bucket handle; elevate libs anteriorly - pump-handle - deep/forced inspiration requires use of other accessory muscles

Question 38

Expiration

Answer 38

- passive - diaphragm relaxes and moves superiorly and intercostal muscles relax allowing ribs to move back into position - inherent elasticity of lung tissue expels air - forced exhalation - requires abdominal muscles (i.e. coughing)