GA1 - Mediastinum Flashcards
Superior border of mediastinum
place connection the cupola or the superior thoracic aperature
Inferior border of mediastinum
diaphragm or inferior thoracic aperature
anterior border of mediastinum
sternum and costal cartilages
posterior border of mediastinum
T1 to T12 vertebrae and related ribs
4 subdivisions of mediastinum
superior, anterior inferior, middle inferior, posterior inferior
superior mediastinum lies between
manubrium sterni and the upper 4 thoracic vertebrae
superior mediastinum is bounded below by? above by? lateral by?
the sternal plane, plane of the thoracic inlet, mediastinal pleurae
superior mediastinum contains lower ends of which small muscles?
sternohyoid, sternothyroid, and longus colli
superior mediastinum contains the remnants of?
thymus gland
superior mediastinum contains what veins?
internal thoracic veins, brachiocephalic veins, upper half of superior vena cava (SVC), left superior intercostal
superior mediastinum contains what arteries?
internal thoracic, aortic arch, brachiocephalic, left common carotid, subclavian
superior mediastinum contains what nerves?
R and L vagi and phrenic nerve, left recurrent laryngeal, cardiac, superficial part of the cardiac plexus
superior mediastinum contains what structures?
trachea and esophagus
superior mediastinum contains which duct?
thoracic
the thoracic duct is a
lymphatic structure in the mediastinum
anterior mediastinum contains which nodes and vessels
lymph
anterior mediastinum contains a small portion of
thymus
anterior mediastinum contains the mediastinal branches of the
internal thoracic vessels
anterior mediastinum contains which ligaments
sternopericardial
anterior mediastinum contains which tissue type?
fat
middle mediastinum contains the covering of the heart
pericardium
middle mediastinum contains which major organ
heart
middle mediastinum contains which aorta
ascending
middle mediastinum contains lower half of the
superior vena cava
superior vena cava receives the
azygous venous arch posteriorly
middle mediastinum contains which part of the trachea?
tracheal bifurcation and both main bronchi
middle mediastinum contains the pulmonary
trunk and R and L pulmonary arteries and veins
middle mediastinum contains the R and L ______ nerves accompanied by the _______ vessels
phrenic; pericardiacophrenic
middle mediastinum contains the deep part of the _____ plexus
cardiac
middle mediastinum contains _______ lymph nodes
tracheobronchial
posterior mediastinum contains descending
aorta and its branches
posterior mediastinum contains posterior ______ VAN
intercostal
posterior mediastinum contains which veins
azygos, hemiazygos, accessory hemiazygos
posterior mediastinum contains which trunk with what nerve?
sympathetic; splanchnic
posterior mediastinum contains which major structure
esophagus
posterior mediastinum contains which lymphatic structure?
thoracic duct
posterior mediastinum contains which nerves that wrap around esophagus also?
vagus
ascending aorta arises from the ____ and ends at ___/____
heart; T4/T5
2 parts of the aorta
thoracic and abdominal
thoracic aorta has 2 branches
visceral and parietal
visceral aorta has 4 branching arteries
EPBM: esophageal, pericardial, bronchial, mediastinal
parietal aorta has 3 branching arteries
SSP: subcostal, superior phrenic, posterior intercostal
parietal means
wall/somatic
visceral means
organs
superior vena cava is in the _____ _____ mediastinum and drains into
middle superior; right atrium
superior vena cava tributaries?
brachiocephalic, azygous
tributaries to the azygous v
right superior intercosal v., hemiazygos, accessory hemizygos
the union of the R and L brachiocephalic vv form the
superior vena cava
L 1st posterior intercostal v drains
directly to the L brachiocephalic v
L 2-4 posterior intercostal v for the
L superior intercostal v
L superior intercostal v drains into
L brachiocephalic v
L 5-8 posterior intercostal v join to form
the accessory hemizygos v
accessory hemizygos crosses at ____ to drain into the ____
T8; azygous
L 9-11 posterior intercostal v form
hemizygos
hemizygos crosses at ___ to drain into
T9; azygous
hemizygos formed by the union of
L subcostal v and L ascending lumbar vv
azygous v is formed by the union of
R ascending lumbar vv and R subcostal v
R 5-11 posterior intercostal vv drain into
azgous
R 2-4 posterior intercostal v joins to form
R superior intercostal v
R 1 intercostal v drains into
R brachiocephalic
2 branches of ascending aorta
L and R coronary aa
coronary arteries responsible for
blood supply to the heart
3 branches to the arch of the aorta
L brachiocephalic, L common carotid, L subclavian
mneumonic for branches of the descending aorta
organs perishable by masteration subsequently show incapacitation
directly infront of the azygos to the L is the
descending aorta
the esophagus lies in both the ____ and ___ mediastinum
posterior and superior
the esphagus is
a muscular collapsible tub about 10 inches long
the abdominal portion of the esophagus is about ____ long
1/2 in
esophagus enters the stomach at its
right side
abdominal portion of the esophagus is covered by ___ on its ___ and ____ side
peritoneum; anterior and lateral
anterior to the esophagus is the
left lobe of the liver
posterior to the esophagus is the
left crus of the diaphragm
blood supply of the abdominal portion of the esophagus
left gastric a
nerve supply to the esophagus
vagus and sympathetic n arising from T1-T4
blood supply to the thoracic portion of the esophagus
esophageal a
blood supply to the neck portion of the esophagus
inferior thyroid aa
vagus and sympathetic nerves arising from T1 -T4 form together to form
esophageal plexus
esophageal plexus has 3 fibers
GVA, preganglionic parasympathetic fibers, and postganglionic sympathetic fibers
preganglionic parasympathetic fibers of the esophagus
peristaltic movement; favors digestion
postganglionic sympathetic fibers
inhibits motility
visceral organs have 2 innervations
sympathetic and parasympathetic: opposite effects
T1-T4 sympathetic nerves are
postganglionic
thymus gland is
a flattened bilobed structure
thymus gland continues to grow until ____, but then
puberty; undergoes involution
when the thymus gland involutes, it
atrophies and replaced with fat
when the thymus is fresh it has
a pink lobulated appearance
thymus is the site of development of
T lymphocytes
thymus gland has a rich blood supply from
inferior thyroid and internal thoracic
the thymus gland is an _____ organ
immunological
the thymus gland is largest in _____; smaller in_____
childhood; adulthood
in the removal of the thymus
immunodeficiency occurs
the thymus secretes
thymosin
thymosin is responsible for
making lymphocytes immunocompetent
longest cranial n in the body that travels all the way down to the abdomen
vagus n
right vagus nerve enters thorax _____ to the right subclavian artery and gives off the ______ ____ nerve
anterior; recurrent laryngeal
left vagus nerve descends int he neck ____ to the left common carotid; gives off the left _____ ____ nerve
posterior; recurrent laryngeal
the left recurrent laryngeal nerve passes underneath the ____ ____ posterior to the _____ ____
aortic arch; ligamentum arteriosum
both vagi nerves breaks up into braches to form the 3 plexuses
pulmonary, cardiac, esophageal
vagus nerve enters the abdomen through the
esophageal opening
what is the sole motor nerve that supplies the diaphragm?
phrenic
phrenic nerve supplies sensory to the central portion of the
diaphragm
phrenic nerves arise from
ventral primary rami of C3, C4, and C5
motor branch of the cervical plexus
C3, C4, C5
phrenic nerve descends down to ____ and ____ mediastinum
superior; middle
what vessels run with the phrenic nerve?
pericardiacophrenic
ligamentum arteriosum is the remnant of the
ductus arteriosus
ligamentum arteriosum connects
aortic arch with pulmonary artery
after birth when the lungs expand the duct of the ductus arteriosum will
constrict and remove communication from artery and aorta
when the ducts of the ductus arteriosum constrict, it will undergo
fibrosus
Patent ductus arteriosus
when the ducts fail to close
PDA causes
blood from aorto to go into the pulmonary artery; increase pressure in pulmonary artery –> pulmonary embolism –> fluid in alveoli –> difficulty breathing –> cyanosis
thoracic duct is a ____ ____ vessel
thin walled; lymphatic
thoracic duct has no
smooth muscle; flimsy
thoracic duct returns all lymph from
all body below diaphragm and left half of the body above the diaphragm
thoracic duct arises as an occasional dilation called the
cisterna chyli
cisterna chyli is at the level of
L2
cisterna chyli recieves the
R and L lumbar trunks; intestinal trunk drains into the left Lumbar trunk
thoracic duct lies between
azygos and descending aorta
during surgery, the thoracic duct can get cut leading to the
leaking out of chyle into the thorax (chylothorax)
chylothorax
fluid in the chest
thoracynthesis
need to take fluid out of the thorax with a needle; fluid will confirm chyle
thoracic chain ganglia are regions of synapse between
pre and post sympathetic ganglionic neurons
thoracic chain ganglia contain
cell bodies of postganglionic sympathetic neurons
thoracic sympathetic trunk is the most _____ placed structure in the mediastinum
laterally
Thoracic sympathetic trunk leaves the thorax next to the ___ ____ passing behind the ___ ___ ___
T12 body; medial arcuate ligament
SP fibers destined to head and neck arise from
T1-T2; T3
grey rami communicans are
bundles of post-gg fibers passing from each thoracic ganglion to the corresponding nerve
SP fibers can enter the white rami and go up the sympathetic chain and synapse in the
cervical ganglion
3 options for a sympathetic postganglionic fiber after synapsing in the cervical ganglion
connect with cervical spinal nerves vi grey rami communicans; connect with carotid arteries; go down and form cardiac n going to the heart
thoracic splanchnic nerves
post ganglionic sympathetic fibers going to thoracic visceral organs T1-T4
abdominopelvic splanchnic nerves pass through
paravertebral ganglia and dont synapse
abdominopelvic splanchnic nerves are
pre gg sympathetic fibers
abdominopelvic splanchnic arise from
T5-T12
Abdominopelvic splanchnic pass through the diaphragm and synapse with the
prevertebral ganglia of the abdomen
greater splanchnic nerves
T5-T9
lesser splanchnic nerves
T10-T11
least splanchnic nerves
T12
cell body contains
nucleus and most of cytoplasn
prevertebral ganglia lies
infront of abdominal aorta
preganglionic sympathetic cell bodies in
lateral horn of T1-L2
parasympathetic postganglionic bodies lie in two ganglia
cranial and intramural (next to or within the target organ)
cranial ganglia: pre fibers are? post fibers are?
long/short
intramural ganglia: pre fibers are? post fibers are?
long/short
paravertebral ganlia: pre fibers are? post fibers are?
short/long
prevertebral ganglia: pre fibers are? post fibers are?
medium in length/ medium in length
abdominopelvic splanchnic nerves: pre fibers are? post fibers are?
medium in length/ medium length
above T1 and below L2 there is only
grey rami communicans
spinal nerves from ventral rami: T1-T11 go to? T12 goes to
intercostal; subcostal
spinal nerves from dorsal rami go directly to
skin and deep back muscles
typical thoracic intercostal nerves level
T3-T6
thoracoabdominal intercostal nerves level
T7-T11
Typical intercostal nerves have 2 branches
lateral cutaneous branch and an anterior cutaneous branch
dermatomes are
segments of skin supplied by a single spinal nerve; imaginary strip of skin