G: Superior, Posterior Mediastinum Flashcards
The medastinum is subdivided into 4 smaller regions _____
superior
inferior (anterior, middle posterior)
Mediastinum extends from the ___ to the ___ (superior to inferior)
and from __ to __ (anterior to posterior)
thoracic inlet to diaphragm
sternum to 12th thoracic vertebrae
The retropharyngeal space is between __ and __
between buccopharyngeal fascia and alar fascia
The retropharyngeal space communicates from the ___ of the skull to the ___ mediastinum
base of skull to superior mediastinum
Sternal angle articulates w. rib __
Sternal angle is at what vertebral level
2
vertebral level t4/5
Anterior mediastinum is between __ and ___
Middle mediastinum is between __ and __
Posterior mediastinum is between __ and __
anterior - between sternum and pericardium
middle - between pericardium and related structures
posterior - between pericardium and T5-T12
Anterior mediastinum is a continuation of the __ fascia
pretracheal fascia
What are the contents of the superior mediastinum?
- thymus gland
- SVC and great vv
- arch of aorta and great aa
- vagus nn and phrenic nn
- trachea and esophagus
- thoracic duct
Thymus gland lies
posterior to ___
anterior to ___
posterior to manubrium
anterior to brachiocephalic vv
Thymus gland is prominent and active in ___ prior to ___
It’s function during this period is for ____
active in childhood prior to puberty
function - T CELL MATURATION
t cell maturation in childhood prior to puberty occurs in the ___
thymus gland
The thymus gland in adults is functionally ___
This appears as a ____
functionally inactive
this atrophies
appears as fatty mass in older adults
What veins are found in the superior mediastinum?
SVC and great veins
great veins = azygos vein, right brachiocephalic vein, left brachiocephalic vein
The LEFT brachiocephalic vein crosses the ___ anteriorly
trachea
The azygos vein empties into the ____
This vein drains the ____
empties into superior vena cava
drains superior to the superior right bronchus
The aortic arch begins and ends at the same level: ____
sternal angle or T4/5
What are the 3 portions of the aorta
- ascending aorta coming out of left ventricle
- arch of aorta begins/ends in superior mediastinum (t4/5)
- descending aorta
The ascending aorta is found in the ___ mediastinum
The descending aorta is found in the ___ mediastinum
both in inferior mediastinum
ascending - middle mediastinum
descending - posterior mediastinum
Aortic arch arces over ____ and ____
left main bronchus and right pulmonary artery
The aortic arch gives rise to 3 great arteries before descending.
What are they?
brachiocephalic trunk
left common carotid artery
left subclavian artery
vagus nerve and phrenic nerves pass through the ____ between a vein and an artery
thoracic inlet
vagus nerve and phrenic nerve are located in ___ mediastinum
superior
Aortic arch is found in the ___ mediastinum
superior
Vagus nerve descends ____ to root of lung
posterior
Vagus nerve provides ___ innervation to ____
parasympathetic innervation to thorax and abdomen
What kind of parasympathetic innervation does vagus nerve carry?
pre-synaptic parasympathetic
Phrenic nerve is what vertebral levels?
Descends ___ to root of lung
C3-4-5 keep me breathing and a live
descends anterior to root of lung
Phrenic nerve supplies __ innervation to ___
somatic innervation to diaphragm
The phrenic nerve follows the course on the _____ via ____
follows course of pericardial sac
via pericardiacophrenic a/v
How do right and left phrenic n get through the diaphragm?
right phrenic - pierces through w/ inferior vena cava @ hiatus (T8)
left phrenic - pierces diaphragm alone right under apex of heart
The trachea is located in the ___ mediasitnum
superior
Trachea descends immediately ___ to the esophagus
anterior
Trachea bifurcates at the inferior limit of the ___
What vertebral level is this?
superior mediastinum
T4/5 (corresponds to sternal angle and rib 2 articulation with manubrial @ manubriaosternal joint)
What is the carina of the trachea?
internal ridge at the bifurcation of the trachea
Numerous ___ are found around the carina
lymph nodes
The carina is usually positioned ___ to median plane
This results in foreign bodies being aspirated into ____
carina is positioned Left of median plane
so Right bronchi is more vortically oriented than left, so right bronchus aspirates more foreign bodies usually
Right main bronchus is shorter and wider than left main bronchus as well
Esophagus
- begins in the ___
- descends immediately ___ to trachea
- pierces diaphragm at ____
- empties into the ___
begins in neck
descends immediately posterior to trachea
pierces diaphragm @ esopahgeal hiatus (T10)
empties into the stomach
Arteries supplying the esophagus arise from ___, ___ and ___
branches to esophagus are branches of:
- thoracic a
- bronchial a
- ascending left gastric a
Venous drainage of the esophagus via __, ___ and ___
azygos vein
hemiazygos vein
left gastric vein
Lymphatics draining the esophageal area are ___
posterior to mediastinum
What is a hiatal hernia?
stomach may herniate through esophageal HIATUS
What are the 2 types of hiatal hernias?
- sliding hiatal hernia
2. paraesophageal hernia
Describe a sliding hiatal hernia
stomach slides freely in the thorax
most common
often asymptomatic
Describe a paraesophageal hernia
fundus goes through hiatus
often fixed in position = risking gastric blood supply!
The danger space is between __ and __
This continues from __ of skull to __ mediastinum
between alar layer and prevertebral layer
from base of skull to posterior mediastinum
infection from the retropharyngeal space can spread into the ___
danger space
