Lungs And Posterior Mediastinum

Front 1

Pleural Cavities

Back 1

Two cavities, one per lung.
A potential space parietal pleura and visceral pleura.

Parietal Pleura: innvervated by general sensory nerves, associated with walls of pleural cavity. Sensitive to pain.

Visceral pleura: adheres to/covers lung and innervated by visceral sensory nerve.

Divide based on what it's next to:
- costal part (next to ribs)
- diaphragmatic part (over mediastinum(
- cervical part (dome shaped layer over cervical extension of cavity at the cupula)

Front 2

Hilum of the lung

Back 2

Part of the lung where the root exits pleural cavity. Pleura reflects to enclose tube but root is not covered.

Front 3

Pleural Recesses

Back 3

Lungs don't fully occupy pleural cavity. This causes recesses to appear, where the two layers of pleura are distinct. Only during forced inspiration are these spaces filled.

Front 4

Tension Pneumothorax

Back 4

When trauma to chest wall (or lung damage from COPD) lets air enter the pleural cavity.

Three types:
- open pneumothorax: air enters cavity from outside
- closed pneumothorax: air enters pleural cavity from lung itself
- tension pneumothorax: air enters pleural cavity on each inspiration, but can't leave

When this happens, the surface tension between the pleural layers is broken and the lung collapses because of inherent elasticity.

Potential space becomes real space!!

Front 5

Justin Williams motor vehicle accident

Back 5

JW (sickle cell patient) is in wreck and gets tension pneumothorax.

Symptoms:
- diminished breath sounds on affected side
- distended neck veins
- tracheal deviation to opposite side

Treatment: needle decompression to let air out of pleural cavity (converts tension pneumothorax into open pneumothorax). Place chest tube.

Front 6

Root of lung

Back 6

Short tubular collection of structures connecting mediastinum and lung.

Covered by sleeve of mediastinal pleura.

Contains pulmonary artery, 2 pulmonary veins, main bronchus, bronchial vessels, nerves and lymphatics.

Front 7

Hilum of lung

Back 7

Bare area of lung outlined by reflection of visceral pleura off lung and onto root as pleura.

Front 8

Right Lung

Back 8

THREE lobes. (superior, middle, inferior).

TWO fissures: oblique and horizontal.

Front 9

Inhaled foreign body

Back 9

Right main bronchus is wider, more vertical so inhaled objects end up on right side.

Usually encoutered in kids around age 2.

Front 10

Left lung

Back 10

TWO lobes, ONE fissure.

Superior lobe (with lingula) and inferior lobe separated by fissure (oblique).

Front 11

Common lung diseases

Back 11

TB: Inhale TB bacteria, get localized lesions that rupture into bronchi

Emphysema: Destruction of alveolar walls, dilated spaces and loss of lung substance

Alveolar cell carcinoma: red rounded tumors develop in all parts of the lung

Secondary carcinoma: hard nodules around lung that came from different (primary) tumor)

Anthracosis: coal miner's lung is deposition of black carbon material in lung, fibrotic central region of lung

Front 12

Hierarchy of airways

Back 12

1) Trachea
2) Main bronchus
3) Lobar bronchus
4) Segmental bronchus
5) Bronchioles

Front 13

Bronchopulmonary segments

Back 13

Area of lung supplied by segmental bronchus, and its accompanying pulmonary artery branch.
Smallest functionally independent region of lung.

Also smallest area that can be removed without hurting rest of lung.

Each segment received its own airway and artery, and veins run between the segments (so they're shared).

Front 14

Bronchopulmonary segments of right lung

Back 14

Superior lobe: Apical segment (S1), posterior segment (S2), anterior segment (S3).

Middle lobe:
Medial segment (S4), lateral segment (S5)

Lower lobe:
Superior segment (S6), medial basal segment (S7), anterior basal segment (S8), lateral basal segment (S9), posterior basal segment (S10).

Front 15

Bronchopulmonary segments of left lung

Back 15

Superior lobe:
Apicoposterior segment (S1/2), anterior segment (S3), superior and inferior lingular segments (S4/S5).

Inferior lobe:
Superior segment (S6), anteromedial basal segment (S7/S8), lateral basal segment (S9), posterior basal segment (S10).

Front 16

Pulmonary arteries/veins

Back 16

Branches of the pulmonary trunk, carry deoxygenated blood from heart to lung.

Veins carry oxygenated blood from lungs to heart.

Front 17

Bronchial arteries

Back 17

Nutritive vascular system of lungs and visceral pleura. Branch off from aorta or its branches. Run with the bronchi.

Front 18

Bronchial veins

Back 18

Drain the parenchyma into the azygos system of veins.

Front 19

Innervation of the lungs

Back 19

Mostly the pulmonary plexus.
Collection of sympathetic/parasympathetic nerves at the bifurcation of the trachea.

Sympathetic (visceral motor) dilates the bronchioles.
Parasympathetic (visceral motor from vagus nerve) constricts the bronchioles.

Visceral sensory also gather information from lungs.

Front 20

Lymphatic drainage of lung

Back 20

Superficial and deep lymphatics drain into tracheobronchial lymph nodes around the roots of the lobar and main bronchi and along sides of trachea.

Efferent vessels from here drain into bronchomediastinal trunks.

Front 21

Phrenic nerve

Back 21

C345 keeps diag alive!

Somatic motor to diaphragm, general sensory from central diaphragm, mediastinal pleura, fibrous pericardium.

Front 22

Muscles of respiration

Back 22

Inspiration:
Accessory: sternocleidomastoid, scalenes (x3)
Principal: ext. intercostals, diaphragm

Expiration:
Quiet breathing: passive recoidl of lung and ribs.
Active breathing: int. intercostals, abdominal muscles.

Front 23

Movement of the thoracic cage

Back 23

Pump handle action (sternum moves up and down) and bucket handle movement (lateral rib movement)

Front 24

Movement of the diaphragm

Back 24

Phrenic nerve innervates, makes it contract and go flatter, allowing lungs to expand.

Front 25

How do we breathe?

Back 25

Pleural cavities (so lungs) expand, creating negative pressure in lungs. (more volume is less pressure).Pressure is higher in atmosphere than in lungs so air rushes in.

Front 26

Posterior mediastinum

Back 26

Bordered by:
ssternal angle T4/T5 (superior), diag (inferior), parietal pleura (lateral), pericardium and diag (anterior) and T5/T12 (posterior)

Contents: aorta, thoracic duct, azygos, and hemiazygos veins, esophagus and its plexus, sympathetic trunks and splanchnic nerves.

Front 27

Esophagus

Back 27

Descends on anterior bodies of vertebrae, innervated by sympathetic nerves and parasymp.(anterior vagal trunk, posterior vagal trunk)

Blood supply is esophageal arteries (from aorta), bronchial arteries, left gastric.

Drained by small vessels returning to azygos system.

Front 28

Azygos venous system

Back 28

Formed by union of abdomen veins on right side. Receives intercostal veins and empties into SVC.

Hemiazygos vein: travels on left (other) side, received lower 4 left intercostal veins.

Accessory hemiazygos vein: travels on left side and receives middle 4 left posterior intercostal veins.

Front 29

Thoracic Duct

Back 29

Begins in abdomen as cisterna chyli, many valves. Collects lymph from RLQ, LLQ, and LUQ.
(RUQ drained by right lymphatic duct).

Between aorta and azygos.

Empties into junction of left internal jugular and subclavian veins.

Front 30

Thoracic splanchnic nerves

Back 30

Sympathetic nerves that come from thorax but travel to abdomen and innervate organs.

Three (greater, lesser, least).

Means innards.