Mediastinum and Lungs Flashcards
1
Q
Mediastinum?
A
- area between two pleural sacs
- superior
- Inferior has three divisions (middle, anterior, posterior)
2
Q
Superior Mediastinum? contents?
A
- sternal angle to T4
- contains trachea, esophagus, and important neural structures
3
Q
Inferior mediastinum? Contents?
A
- Middle
- heart and pericardium - Anterior
- posterior to sternum and anterior to pericardium
- sternopericardial ligaments
- lymph nodes (cancer)
- thymus gland
- thyroid gland (can descend to substernal) - Posterior
- anterior to vertebral bodies and posterior to pericardium
- esophagus, thoracic duct, Vagus nerve
4
Q
Esophagus location?
A
- extends lower end of pharynx to stomach
- midline structure
- no adventitia
5
Q
Esophagus function?
A
- distensible: will accommodate anything that can be swallowed
- superior part: striated muscle for voluntary initiation of swallowing
- inferior part: smooth muscle for autonomic control of swallowing
6
Q
Esophagus innervation?
A
-Vagus nerve runs behind it
7
Q
Left recurrent laryngeal nerve? Clinical significance?
A
- branch of Vagus nerve goes back up and wraps around Aorta
- hoarse voice could be caused by Aortic aneurysm (very rare)
- put on differential
8
Q
Varicose veins of esophagus?
A
- anastomosis of veins with left gastric veins
- associated with portal hypertension
- blood backs up into these veins of hepatic portal system
- can cause acid reflux and bleeding
9
Q
Thoracic Duct path? Function?
A
- Starts in abdomen as dilated lymph duct called Cisterna Chyli
- goes through aortic opening and travels in posterior mediastinum
- enters at junction of left Internal Jugular vein and Left Subclavian vein
- Function: receives lymph from most of the body including left side of head and neck
10
Q
Trachea structure?
A
- midline, mobile
- 16-20 C shaped bars of hyaline cartilage on anterior side
- elastic fibers on posterior side
- enclosed by fibrous muscle covering
- divides T5/T6
- 10 cm in length
11
Q
Carina of Trachea?
A
- ridge down midline of trachea
- anterior posterior ridge where trachea branches
- richly innervated by Vagus nerve
12
Q
If someone swallows something, where will it most likely go?
A
- right main stem bronchi
- larger and more midline with trachea
13
Q
What supplies the main bronchi with blood?
A
- bronchial arteries
- supply non-respiratory areas of lungs and visceral pleura with oxygenated blood
- from Aorta
14
Q
When someone get’s ear cleaned out, why would they cough?
A
- external ear: Auricular Temporal nerve
- connected with Vagus nerve to larynx and trachea
- Vagus nerve wanders everywhere (esophagus, cardiac plexus to slow HR, abdomen)
15
Q
Function of lungs?
A
-gas exchange: O2 in, CO2 out
16
Q
How are lungs attached?
A
- attached to heart and trachea by root and pulmonary ligaments
- double fold of mediastinal pleura
- root of hilum (bronchi, artery, vein, autonomic nerve fibers)
17
Q
Left lung lobes?
A
- Superior and inferior lobes separated by an oblique fissure
- Clinical: pneumonias can be specific to one lobe
- has lingula
18
Q
Right lung lobes?
A
- horizontal fissure separates superior and middle lobes
- oblique fissure separates inferior from middle and superior lobes
19
Q
Lung Pleura?
A
- Parietal pleura
- lines chest cavity
- diaphragmatic
- mediastinal (Phrenic N.)
- costal (Intercostal N.)
- apical - Visceral pleura
- rests on lungs
- sends projections inwards
- no sensory innervation
20
Q
Parietal pleura innervation and blood supply?
A
- Phrenic N. (sensory and motor)
- Intercostal N.
- Intercostal arteries
21
Q
Visceral pleura blood supply and innervation?
A
- Bronchial arteries
- no sensory innervation
22
Q
Pleural cavity where pleural effusions occur?
A
- between parietal and visceral pleura
- fluid accumulates here
- Pleurocentesis: removal of fluid from pleural cavity (stick needle superior to rib into pleural cavity)
23
Q
Costal endothoracic fascia?
A
- thin layer of fascia separates costal pleura from ribs
- thickened superiorly over apex of lungs (simpson’s fascia)
24
Q
Costomediastinal recess?
A
- only on left side
- goes over bare area of heart
- where lingual of lung extends to pericardium
25
Costodiaphagmatic recess?
- found on both right and left sides
- surrounds area of diaphragm
- during deep respiration lung extends inferiorly into recess
- when taking fluid from lungs, tell patient not to take deep breath
26
Cupola?
suprapleural membrane over apex of lungs
27
Hilar lympadenopathy?
swollen lymph nodes around hilum
28
Bronchopulmonary segments?
- third order branch
- largest within lobe
- 10 segments each lung
- separated by septa from visceral pleura
- pulmonary veins are intersegmental
- pulmonary arteries accompany bronchi
- pneumonia can occur in segments and not spread to others
29
Ventilation?
moving air inward via muscles of respiration
30
Diffusion in alveoli? Thickened membrane?
- O2 and CO2 diffuse through alveolar membrane
- CO2 takes less effort to diffuse
Pulmonary Fibrosis
- if alveolar membrane thickens, patients cannot get enough O2
- treat with O2 tank
31
Expiration?
passive process that allows air to flow in and out of lungs by elastic fibers
32
Pulmonary artery?
- bring deoxygenated blood from right ventricle to lungs
| - elastic
33
Pulmonary veins?
- bring oxygenated blood from lungs back to heart
- enter left atrium
- no valves
- 4 veins
34
Bronchial arteries?
- come off Aorta
| - supply non respiratory areas of lungs with blood
35
Bronchial veins?
-drain from lungs to azygous, hemiazygous, or intercostal veins
36
Azygous vein?
drains into superior vena cava
37
Lymph drainage of hilum?
- pulmonary nodes
| - tracheobronchial nodes
38
Lung innervation?
autonomic
39
Diameter of lungs after Inspiration?
1. vertical diameter: contraction of diaphragm
2. AP diameter: shape of ribs, intercostals
3. Transverse diameter: shape of ribs, intercostals
