pleura, lung and mediastinum

Question 1

Mediastinum boundaries:

Answer 1

-Superiorly: Thoracic outlet and root of neck
Inferiorly:Diaphragm
Anteriorly:Sternum
Posteriorly:T1-T12

Question 2

Parts of the mediastinum:

Answer 2

Superior mediastinum:

Inferior mediastinum:
1)anterior mediastinum:Space between pericardium and sternum
2)Middle mediastinum; Consists of pericardium and heart
3)Posterior mediastinum; between pericardium and vertebral column

Question 3

Superior mediastinum boundaries:

Answer 3

Above: thoracic outlet
Below: transverse line on t4-t5
Anteriorly: Manubrium sterni
posteriorly: upper T4 vertebra
On each side: mediastinal surface of lung and its pleura

Question 4

contents of superior mediastinum:

Answer 4

-Thymus, trachea, thoracic duct
-Large veins and large arteries
-esophagus and sympathetic trunks

doesnt have the aorta and phrenic nerves

Question 5

Inferior mediastinum boundaries and contents:

Answer 5

Boundaries:
Front- body of sternum
Behind: lower eight thoracic vertebra

Contents:
Thymus (anterior)
Heart within pericardium and phrenic nerves(middle)
esophagus and thoracic duct (Posterior)
descending aorta and sympathetic trunks(Posterior)

doesnt have the large veins and arteries

Question 6

pleura consists of:

Answer 6

Parietal pleura- cervical pleura, costal pleura, diaphramatic plerua, mediastinal plerua
visceral pleura
plerual cavity
pleural fluid

Question 7

Parietal pleura:

Answer 7

Cervical pleura:
-reaches the neck
-lines under suprapleural membrane
**-is slightly above medial third of clavicle **

Costal plerua:
-lines inner surface of ribs, costal cartialage, back of sternum, intercostal spaces and sides of vertebral bodies
-diaphramatic pleura: covers thoracic surface of diaphragm
-Mediastinal pleural: becomes continous with visceral pleura
at the hilum, it is refelected as a cuff around the vessles and bronchi.

Question 8

Visceral plerua:

Answer 8

parietal and visceral pleura are continous with one another in a cuff

covers outer surfaces of lung except hilum

Question 9

Costodiaphragmatic recesses:

Answer 9

-between costal and diaphragmatic pleura
-during inspiration costal and diaphragmatic pleura separate

Question 9

pulmonary ligament, pleural cavity, pleural fluid:

Answer 9

Pulmonary ligament:
-loose fold hangs from pleural cuff
-allows movement of pulmonary vessles and large bronchi during respiration

Pleural fluid:reduces friction

Question 10

Costomediastinal recess:

Answer 10

-between costal and diaphragmatic pleura
-anterior borders of lung slide in and out during inh and exh

Question 11

Nerve supply of pleura:

4 areas: parietal
1 area visceral:

Answer 11

parietal pleura: sensitive to pain, temp, pressure and touch

-Costa pleura: Intercostal nerves

-mediastinal pleura: phrenic nerves

Diaphragmatic pleura:phrenic nerve (over dome) and lower 6 inercostral nerves.

-Visceral pleura: sensitive to stretch only
- Autonomic nerve supply from pulmonary plexus

Question 12

Morphology of lung:

Apex, base, mediastinal surface,hilum,ant post borders

Answer 12

Apex: reaches neck, 1 inch above clavicle
Base: Concave, sits on diaphragm
Costal surface: Convex
Mediastinal surface: Concave to fit pericardium
Hilum: Bronchi, vessles and nerves enter and leave this area
-Anterior border: thin and overlaps the heart, left side has cardiac notch nad lingula
-Posterior border: extends from C7-T10
Inferior border:contains costodiaphragmatic recess where thoracentisis is done, lower margins of parietal pleura cross 8th 10th and 12th rib

Question 13

Right lung:

Answer 13

-larger than left
-oblique fissure: runs from inferior border to posterior
-horizontal fissure: runs horizontally at 4th costal cartialage and meets with oblique fissure at midaxillary line
-middle lobe:small traingular lobe
-anterior border of right lung: begins behind sternoclavicular joint, runs down into sternal angle until it reaches xiphosternal joint.

Question 14

Left lung:

Answer 14

Lingula
Cardiac notch
anterior border of left lung:turns sharply downward to xiphosternal joint

Question 15

Root of lung:

Answer 15

contains:
1)Bronchi
2)pulmonary arteries and veins
3)Lymph vessles
4)nerves
5)bronchial arteries and veins

Question 16

Bronchopulmonary segments:

Answer 16

-Anatomical, functional and surgical units of lungs

Right lung bronchopulmonary segments:
-superior lobe: apical, posterior, anterior
-Middle lobe: lateral, medial
-Inferior lobe: Apical, anterior basal, posterior basal, medial basal, lateral basal

left lung bp segments:
Superior lobe: apical, anterior , posterior , superior and inferior lingular
Inferior Lobe: apical, anterior basal, posterior basal, lateral basal, medial basal

Question 17

Blood supply of lungs:

Answer 17

Bronchial arteries:
supply bronchi and connective tissue of lung and visceral pleura

Bronchial veins: communicate with pulmonary veins and drain into azygous and hemiazygous veins

Alveoli: receive deoxygenated bkood from terminal branches of pulm arteries
oxygenated blood leaves capillaries into tributaries of pulm vein

Question 18

Nerve supply of lungs:

Answer 18

at route of each lung: efferent and afferent autonomic nerve fibers

-formation:
-** Branches of sympathetic trunk: vasoconstriction and bronchodialation
-Parasympathetic fibres of vagus nerve**: efferent bronchoconstriction and vasodialation and inc gland secretion

-affrent impulses come from bronchial mucous membrane and from stretch receptors from alveolar walls pass to CNS.

Question 19

Lymph drainage of lungs:

Answer 19

not present in alveolar walls
Superficial plexus:
-Lies beneath visceral pleura
-drains over the surface of the lung towards the hilum

**Deep plexus: **
-travels along bronchi and pulmonary vessles toward the hilum of the lungs, passing thru pulmonary nodes.
-All the lypmph then enters bronchopulmonary nodes in hilum of lung.

-all lymph from the lung LEAVES HILUM and drains into TRACHEOBRONCHIAL NODES, then into BRONCHOMEDIASTINAL TRUNKS