sp14_-_human_anatomy_exam_4_20141210195212 Flashcards
What makes up the thoracic skeleton?
- 12 pairs of ribs and costal cartilages- 12 thoracic vertebrae and intervertebral discs- sternum
What is the superior thoracic aperture also known as? What travels through it?
- thoracic inlet- trachea, esophagus, vessels, and nerves
What are the boundaries of the superior thoracic aperture?
- posterior: T1 vertebrae- lateral: first pair of ribs and their costal cartilages- anterior: superior border of the manubrium
What is the inferior thoracic aperture also known as?
thoracic outlet
What are the boundaries of inferior thoracic outlet?
- posterior: T12 vertebrae- posterolateral: 11th and 12th pairs of ribs- anterolateral: joined costal cartilages of ribs 7-10 (forming the costal margin)- anterior: the xiphisternal joint
What are some of the structures that pass through the diaphragm? That pass behind it?
- pass through: IVC (T8) and esophagus (T10)- pass behind: aorta (T12)
What is the difference between true, false, and floating ribs? Name which rib numbers fall under what category.
- true ribs: ribs 1-7; attach directly to sternum through their own costal cartilages- false ribs: ribs 8-10; have cartilages that are joined to the cartilage of the rib just superior to them (indirect connection to sternum)- floating (free) ribs: ribs 11 and 12; have rudimentary cartilages that do not connect even indirectly with the sternum; they end in the posterior abdominal muscles
Name the 4 major bony structures of a rib and describe each.
- head: articulates with 2 vertebral bodies and 1 disc- tubercle: articulates with 1 transverse process- body: region of greatest curve; angle is found here- costal groove: formed by intercostal veins, arteries, and nerves
Name the 3 major bony structures of the sternum and describe each.
- manubrium: has clavicular notch for sternoclavicular joint- body: joins manubrium at the sternal angle (of Louis)- xiphoid process: lowest point of the sternum
What is the name of the joint between the manubrium and sternum? At what vertebral level is this joint found?
- manubriosternal joint at the sternal angle of Louis- found opposite the second pair of costal cartilages at the level of the T4/T5 intervertebral disc
What type of joint is the manubriosternal joint? The xiphisternal joint?
- manubriosternal joint: secondary cartilaginous joint (symphysis and slightly moveable)- xiphisternal: primary cartilaginous joint (synchondrosis and immovable)
What are the two heads of the pectoralis major muscle?
clavicular and sternocostal heads
What envelopes pectoralis minor? What pierces this fascia?
- clavipectoral fascia- thoracoacromial artery and cephalic vein
What is the supensory ligament of the axilla composed of?
clavipectoral fascia (envelopes pectoralis minor) and costocoracoid membrane
What composes the anterior thoracic wall? (bones, muscles, vessels, and nerves)
- ribs and sternum- pectoral, intercostal, and subcostal muscles- intercostal vessels and nerves- internal thoracic vessels and nerves
Name the 3 intercostal muscles. What is the general direction of the fibers of each?
- external intercostal muscle: down and in (direction of fingers when you put your hands in your pocket)- internal intercostal muscle: up and out (perpendicular direction to external)- innermost intercostal muscle: more vertical fibers
Where is the subcostal muscle found?
on the internal surface of the lower ribs; each band of muscle attaches to every other rib so it looks like it is passing over some ribs
Name all 8 muscles of the thoracic wall.
- external intercostal muscle- internal intercostal muscle- innermost intercostal muscle- transversus thoracis muscle- subcostal muscle- levatores costarum muscle- serratus posterior superior muscle- serratus posterior inferior muscle
Which posterior serratus muscle is associated with inspiration? With exspiration?
- inspiration: serratus posterior SUPERIOR muscle- exspiration: serratus posterior INFERIOR muscle
What is the name of the vessels/nerves in the costal groove and what is their orientation? What is the name of the vessels/nerves found above each rib and what is their orientation?
- costal groove: intercostal vessels/nerve; from superior to inferior, VAN (“driving a VAN from coast-to-coast, or inter-coastal”)- above each rib: collateral branches; from superior to inferior, NAV
Between what layers do intercostal and collateral nerves and vessels travel?
between the internal and innermost intercostal muscles
Where is the safest site for a needle to insert into the anterior thoracic wall?
slightly above the rib so that it does not hit the intercostal or collateral nerves and vessels
What do the intercostal and collateral vessels and nerves join to become when they reach the sternum?
anterior perforating branches of the intercostal nerves and vessels
What are the posterior intercostal arteries branches of?
the aorta
What type of membrane is the pleura?
serous secreting membrane that reduces friction
What are the 2 layers of the pleura? What are the differences between the two in terms of what they cover and their pain sensitivity?
- parietal pleura: covers thoracic walls; very sensitive to pain due to the intercostal and phrenic nerves- visceral pleura: covers the lunges; NOT sensitive to pain because no sensory nerve supply
Where do the 2 layers of pleura meet?
at the root of the lung
Where is the middle mediastinum located in regards to the pleura?
between the layers of parietal pleura that surround the lungs
What is the clinical significance of the pleural cavities (between the 2 layers of pleura)?
- potential cavity that can become an actual cavity- pathological fluid (effusion) may fill the space and compress the lungs which makes breathing difficult- pleural effusions are visible on chest films and can obscure the lung in film
What are the 4 parts of the parietal pleura?
- cervical pleura (at the top of the lung)- costal pleura (against the ribs)- diaphragmatic pleura- mediastinal pleura
What is the difference between pneumothorax and hemothorax?
- pneumothorax: accumulation of air in the pleural cavity; collapse the lung due to its own elasticity- hemothorax: accumulation of blood in the pleural cavity; may cause adhesion and infection if not removed
What is pleurisy?
- inflammation of the pleura- usually leads to formation of pleural adhesion- between the parietal and visceral pleura- can produce exquisite pain relative to parietal pleura
What is a pleural tap used for? Where should it be performed?
- used for aspiration of fluids- often performed in midaxillary line or slightly posterior- needle usually inserted through intercostal space 6 or 7 (if it is in 8 or 9, it may pierce the diaphragm, liver, or spleen)- needle is positioned close to the superior border of the rib to avoid injury to the intercostal nerves and vessels
How many lobes are in the right lung? Name them. How many in the left lung? Name them.
- right lung: 3 (upper/superior, middle, and lower/inferior)- left lung: 2 (upper/superior and lower/inferior)
In what lung(s) can you find an oblique (major) fissure? In what lung(s) can you find a horizontal (minor) fissure?
- oblique: both lungs- horizontal: right lung only
In general, what is the layout of the hilum (pulmonary vessels and bronchi)? What is the exception?
- pulmonary artery: most superior structure- pulmonary veins: most anterior/inferior structure- bronchi: most posterior structure- EXCEPTION: on the right lung, the bronchi are more superior to the pulmonary arteries
What does the root of the lung connect? What covers it? What does it consist of?
- connects lung to the mediastinum- covered in a sleeve of pleura- consists of bronchi and pulmonary vessels
Where is the pulmonary ligament found? What is contained within it?
- inferior portion of the sleeve of pleura that covers the root of the lung- contains only a few lymph vessels
True or false: Lymph nodes are present, along with the pulmonary vessels and bronchi, in the hilum of each lung.
true
Describe the path of the phrenic nerve in regards to the roots of the lungs. What does it also run closely to?
- passes anterior to the roots- closely applied to the pericardial sac
Along what nerve do the pericardiacophrenic vessels run? What are they branches of?
- runs with the phrenic nerve- branches of the internal thoracic arteries and brachiocephalic veins
Describe the path of the vagus nerve in regards to the roots of the lungs. What does it also run closely to?
- passes posteriorly to the roots of the lungs- closely applied to trachea, esophagus, and aorta
What do the bronchial arteries supply? What are they branches of?
- supplies nutrients to bronchi and lungs- branches of the aorta
What is the sympathetic input to the right and left pulmonary plexuses and cardiac plexus? The parasympathetic input?
- sympathetic: fibers from the paravertebral ganglion of the sympathetic trunk- parasympathetic: fibers from the vagus nerves
Where does the right lymphatic duct and the thoracic duct drain?
at the venous angle (junction of the subclavian and internal jugular veins)
What structure does the right recurrent laryngeal nerve curve under? The left recurrent laryngeal nerve?
- right recurrent laryngeal: under the subclavian artery- left recurrent laryngeal: under the aortic arch
Describe the splitting of the bronchi.
trachea -> 2 primary (main) bronchi -> 2-3 secondary (lobar) bronchi each -> 8-10 tertiary (segmental) bronchi
Each bronchi segment is supplied by a single branch of the pulmonary artery. Why is this clinically significant?
allows for removal of individual lung segments in cases of diseased segments
What are the boundaries of the mediastinum?
- median space between the 2 pleural sacs- extends from thoracic inlet to the diaphragm- extends from the sternum to the 12th thoracic vertebrae
What is the inferior boundary of the superior mediastinum?
the sternal angle and T4-T5 IV disc
What are the borders of the anterior mediastinum?
between the sternum and the pericardium
What are the contents of the middle mediastinum?
- pericardium and heart- phrenic nerves applied to the pericardium- pericardiacophrenic vessels- roots of the great vessels to and from the heart
What are the boundaries of the posterior mediastinum?
between the pericardium and T5-T12 vertebrae
What is the pericardium?
tough fibrous sac lined with serous membrane
What are the 2 portions of the pericardium? Describe each.
- fibrous portion: attached to the diaphragm inferiorly- serous portion: divided into the parietal and visceral layers
What are the 8 roots that pierce the pericardium?
SVC, IVC, aorta, pulmonary trunk, and 4 pulmonary veins
What layer of the pericardium is also called the epicardium?
visceral pericardium
What layer of the serous portion of the pericardium lines the outer fibrous pericardium?
parietal pericardium
What is the pericardial sac?
complete inner pericardial membrane (parietal and visceral layers)
What is the pericardial cavity?
inside the pericardial sac; potential space between the serous and parietal layers; contains only a small amount of serous fluid
What is pericardial effusion? What condition is it associated with?
- accumulation of fluid in the pericardial cavity that results in compression of the heart- common in conjunction with congestive heart failure
What is hemopericardium? What conditions is it associated with? What does it lead to?
- accumulation of blood in the pericardial cavity- associated with penetrating heart wounds or perforated heart muscle following MI- arterial bleeding into the cavity leads to CARDIAC TAMPONADE (compression of the heart and roots of the great vessels)
Name the 4 chambers of the heart and the borders of the heart that they occupy.
- right atrium: right border- right ventricle: inferior border and anterior surface- left atrium (base): superior border and posterior surface- left ventricle: left border and apex
Does the majority of the heart sit to the right or left of the midline of the body?
2/3 of the heart sits to the left of the midline
Where is the best place to listen to the auscultation of the heart?
left 5th intercostal space
What lies in the atrioventricular (AV) groove (AKA coronary sulcus)?
- coronary artery lies in this on the right side- coronary sinus lies in this on the left side
What is the name of the two grooves/sulci that are between the left and right ventricles?
- anterior interventricular (IV) groove/sulcus- posterior interventricular (IV) groove/sulcus
What is the name of the septum that separates the right and left atrium?
interatrial (IA) septum
What is the name of the septum that separates the right and left ventricles?
interventricular (IV) septum
What is the surface texture of the right and left atrial wall? Of the right and left auricle (roof)?
- atrial wall: smooth muscular surface- auricle (roof): rough with pectinate muscles
What is the vertical ridge that separates the smooth atrial wall from the rough pectinate auricle surface?
crista terminalis
What is the depression in the interatrial wall?
fossa ovalis
What is the AV orifice?
leads into the right ventricle from the right atrium
What are the openings through which blood flows into the right atrium?
- SVC and IVC- coronary sinus
What is the sinus venarum?
the smooth, thin-walled posterior part of the right atrium on which the SVC, IVC, and coronary sinus open
What is the right AV valve also known as (tricuspid or bicuspid)? Name the cusps.
- tricuspid- anterior, septal, and posterior cusps
What anchors the cusps of the AV valves?
chordae tendineae attached to papillary muscles
What is the significance of each of the papillary attaching to 2 adjacent cusps?
to prevent separation of the cusps and to prevent them from inverting and blood going back into the right atrium
What is the largest of the papillary muscles in the right ventricle? What is the smallest?
- largest: anterior papillary muscle- smallest: septal papillary; often multiple muscles
What are the irregular muscular elevations along the wall of the right ventricle?
trabeculae carneae
What is the curved muscular bundle that runs from the inferior part of the interventricular septum to the base of the anterior papillary muscle?
septomarginal trabecula (moderator band)
What is the purpose of the septomarginal trabecula (moderator band)?
carries part of the right bundle branches of the AV bundle to the anterior papillary muscle
In the right ventricle, what is the name for the outflow track that leads to the pulmonary trunk?
conus arteriosus
What embryonic structure is the conus arteriosus derived from?
embryonic bulbus cordis
What enters into the left atrium?
4 pulmonary veins enter the atrium posteriorly
What can be seen in the left atrium on the IA wall?
valve of foramen ovale
Which auricle is larger: right or left?
right
What is the left AV valve also called? Name the cusps.
- bicuspid valve or mitral valve- anterior and posterior cusps
How many papillary muscles are in the left ventricle? Name them.
2; anterior and posterior and they control both cusps
Which ventricle has larger papillary muscles?
left ventricle has larger papillary muscles (although it only has 2)
What is the difference in the trabeculae carneae between the left and right ventricles?
trabeculae carneae is finer and more numerous in the left than those in the right ventricle
True or false: The right ventricle forms the apex of the heart.
FALSE. The LEFT ventricle forms the apex of the heart.
True or false: The moderator band is larger in the left ventricle than the right ventricle.
FALSE. There is no moderator band in the left ventricle!
Is the muscular wall thicker in the right or left ventricle? By how much?
muscle wall in the left ventricle is typically 3x thicker (1-1.5 cm thick)
What is the difference between the aortic vestibule and the aortic orifice?
aortic vestibule is the smooth-walled non-muscular superioanterior outflow part of the left ventriclethat leads to the aortic orifice which is surrounded by a fibrous ring to which the cusps of the aortic valve are attached
Which is of the great vessels (aorta or pulmonary trunk) is more anterior?
- pulmonary trunk: more anterior- aorta: more posterior*think “AP” and “PA”
How many cusps make up the aortic semilunar valve? Name them.
three: left, right, and posterior
How many cusps make up the pulmonary semilunar valve? Name them.
three: left, right, and anterior
What is the ligamentum arteriosum? Where is it located? What was its original purpose?
- remnant of the fetal ductus arteriosus- located between the left pulmonary artery and aorta- served to shunt blood from the right ventricle to the aorta since the lungs were not functional
Where is the ligamentum arteriosum located with reference to the left recurrent laryngeal nerve?
left recurrent laryngeal nerve is posterior to the ligament
Where does the right coronary arise from? What sulcus does it travel in?
- arises from the right side of the ascending aorta just superior to the right aortic semilunar cusp- travels in the coronary sulcus around the right side of the heart
What does the right coronary artery become as it turns inferior?
posterior interventricular artery
What is the first branch of the right coronary artery?
anterior right atrial branch
What is the branch of the anterior right atrial artery? What does it supply?
Sinuatrial Nodal Artery; supplies the SA node (the “pacemaker of the heart”)
What could occur if there was occlusion of the SA nodal artery?
failure of the SA node: sinus arrest or sinus block and cardiac arrhythmia
What does the right marginal artery branch off of? What does it supply?
- branch of the right coronary artery- supplies the lateral right ventricle
What is another name for the posterior interventricular artery? Which sulcus does it run in? What does it travel toward?
- posterior descending artery (PDA)- runs in the posterior IV sulcus- travels towards the apex of the heart
Name the branches of the right coronary artery.
- anterior right atrial branch (with sinuatrial nodal branch)- anterior right ventricular branch- right marginal branch- posterior interventricular (not necessarily a branch, continues as this)
Where does the left coronary artery arise from? What does it divide into?
- arises from the left side of the ascending aorta originating just superior to the left aortic semilunar cusp- divides into anterior interventricular artery and circumflex arteries
What is the anterior interventricular artery also called? What sulcus does it run in? Where does it travel toward toward?
- left anterior descending artery (LAD)- runs in the anterior IV sulcus- travels towards the apex of the heart
What two arteries anastomose at the apex of the heart?
anterior interventricular artery (LAD) and posterior interventricular artery (PDA)
In what sulcus does the circumflex artery run? What does it supply?
- runs in the coronary sulcus (atrioventricular sulcus that circumnavigates the heart)- circles around the left side of the heart to supply the posterior aspect of the left ventricle
What branch does the circumflex artery give off? What does it supply?
left marginal branch that supplies the lateral left ventricle
What does the circumflex artery become as it turns inferior?
posterior left ventricular artery
What is the difference in dominance between the right and left coronary arteries?
- right coronary artery dominant: 65%; crosses over to supply the left ventricle posteriorly- left coronary artery dominant: 15%; crosses over to supply the right ventricle posteriorly- balanced arterial pattern: 20%
What does it mean to be more dominant in terms of the coronary artery?
the dominant coronary artery gives off the posterior interventricular artery and supplies more of the heart
What is the coronary sinus? In what sulcus does it lie? Where does it drain into?
- vein into which most of the veins of the heart drain- lied in posterior portion of the coronary sulcus- opens into the right atrium (between the IVC and AV orifice)
With what arteries does the great cardiac vein travel? Where does it empty?
- travels with the anterior interventricular artery in the anterior IV sulcus and then runs in the coronary sulcus superiorly to travel with the circumflex artery around the left side of the heart- empties into the coronary sinus posteriorly
With what artery does the middle cardiac vein travel? Where does it empty?
- travels with posterior interventricular artery in the posterior IV sulcus- empties into the coronary sinus superiorly
With what arteries does the small cardiac vein travel? Where does it empty?
- travels with the right marginal artery along the lateral right ventricle and then turns right to run in the coronary sulcus superiorly and travels with the right coronary artery around the right side of the heart- empties into the coronary sinus posteriorly
True or false: If the right marginal vein does not join the small cardiac vein, it enters the right atrium directly.
true
With what arteries do the anterior cardiac veins travel? Where does it empty?
- travels with the anterior right ventricular arteries- ascends toward the right auricle and empties DIRECTLY into the right atrium
What cardiac vein does not empty into the coronary sinus?
anterior cardiac veins
What vessels are sometimes imported to become vessels of the heart? How is this done?
- great saphenous vein (most common), internal thoracic artery, and radial artery- harvested from the anterior/medial region of the thigh/leg (great saphenous vein); can be sutured into aorta and distal branch of a coronary artery; must consider the arrangement of the valves within the saphenous vein!
Why is it possible to harvest an artery without removing blood supply to that area?
because of anastomoses
True or false: The heart requires CNS innervation to initiate a heartbeat.
FALSE. With sufficient oxygen and nutrition, a heart will beat without CNS initiation.
True or false: The ANS has an effect on the heartbeat.
true
From where does the heart receive sympathetic innervation? Parasympathetic innervation?
- sympathetic: T1-T5- parasympathetic: vagus nerve (CN X)
True or false: There are both parasympathetic and sympathetic nerve fibers n the superficial and deep cardiac plexuses of nerves.
true
Does the cardiac plexus contain pre- or post-ganglionic sympathetic fibers? Parasympathetic fibers?
- post-ganglionic sympathetic fibers- pre-ganglionic parasympathetic fibers
Where do the cell bodies of the post-ganglionic parasympathetic fibers lie?
near the SA and AV nodes and along the coronary arteries
What are the effects of sympathetic stimulation of the heart?
- stimulation of the nodal tissue increases the heart rate and the force of the contractions- produces dilation of the coronary arteries to supply more oxygen and nutrients to the myocardium during periods of increased activity
What are the effects of parasympathetic stimulation of the heart?
- slows the heart rate and reduces the force of contraction- constricts the coronary arteries to save energy between periods of increased demand
What is the location of the superficial cardiac plexus? The deep cardiac plexus?
- superficial: inferior to the aortic arch and between it and the pulmonary trunk- deep: between the aortic arch and the tracheal bifurcation
What do the nerve branches of the coronary plexus affect?
- nodal tissue and other components of the conductive system- coronary blood vessels- atrial and ventricular musculature
What does the conduction system of the heart consist of?
SA node, AV node, and AV bundle
Where is the SA node located? The AV node and bundle?
- SA node: in crista terminalis between the right atrium and SVC- AV node and bundle: in IA septum near the coronary sinus opening
True or false: The SA and AV nodes are seen in the gross lab as small bumps.
FALSE. The nodes are too small to be seen grossly.
Describe the conduction pathway.
- impulses initiated by the SA node travel to the AV node- propagation allow for atrial contraction- impulses then travel to the AV bundle and IV septum- bundle divides into right and left bundle branches- Purkinje fibers travel to ventricles for contraction
What are the subendocardial plexus of ventricular conduction cells know as?
purkinje fibers (network of specialized cells that spreads throughout the ventricle to supply the ventricular musculature including the papillary muscles)
What would occur if there were damage to the conduction system of the heart?
cardiac arrhythmia
What would occur if there were damage to the AV node? How may this be controlled?
- heart block (impairment of the system with uncoordinated contraction so the ventricles may contract at their own rate)- pacemaker may be inserted to control the contractions
Describe the placement of a pacemaker.
- battery pack inserted subcutaneously below the clavicle- electrode threaded down through the SVC to the right atrium and passed through the AV valve into the right ventricle- electrode terminal firmly fixed to trabeculae carneae and placed in contact with the endocardium of the ventricular wall
How is the retropharyngeal space related to the superior mediastinum?
the retropharyngeal space between the buccopharyngeal and alar deep cervical fascia layers communicates from the base of the skull into the superior mediastinum
What are the contents of the superior mediastinum?
- thymus gland- great vessels (brachiocephalic veins, superior part of SVC, arch of aorta and the roots of its major branches)- vagus and phrenic nerves- cardiac plexus of nerves- LEFT recurrent laryngeal nerve- trachea- esophagus- thoracic duct
What are the 3 major branches of the aortic arch?
- brachiocephalic trunk- left common carotid- left subclavian artery
Which is longer: the right or left brachiocephalic vein?
left
Where is the thymus gland located? What is the difference between the thymus in a child vs. an adult?
- just posterior to the manubrium; lies anterior to the brachiocephalic veins- prominent and active in childhood and puberty; functionally inactive and atrophies in adults (may appear as a fatty mass in older individuals)
Where do the right and left brachiocephalic veins converge and what do they become?
converge at the right margin of the manubrium and become the SVC draining into the right atrium
Where does the left brachiocephalic cross the trachea? Why is this clinically significant?
- left brachiocephalic vein crosses trachea anteriorly- it may be injured during an emergency tracheotomy if it is performed too low
At what level(s) does the aortic arch begin and end? What does it arch over?
- begins and ends at the same level = sternal angle or T4/T5- arches over the left pulmonary artery and left main bronchus
True or false: The aortic arch lies at the inferior plane of the superior mediastinum.
true
Between what 2 structures does the vagus nerve enter the thorax? Does it descend anterior or posterior to the root of the lung?
- enters thorax between the subclavian artery and vein- descends posterior to the root of the lung
Between what 2 structures does the phrenic nerve enter the thorax? Does it descend anterior or posterior to the root of the lung?
- enters the thorax between subclavian artery and vein- descends anterior to the root of the lung
What are the origin of the fibers that make up the phrenic nerve? What type of innervation is provided by the phrenic nerve and what does it innervate?
- anterior rami of C3-C5- somatic innervation to the diaphragm
Is the trachea anterior or posterior to the esophagus?
trachea descends immediately anterior to the esophagus
Where does the trachea bifurcate? What is this bifurcation called? What structures can be found here?
- bifurcates at the inferior limit of the superior mediastinum around the base of the T4 vertebrae- carina- numerous lymph nodes are found at the carina
Into which bronchi are foreign bodies usually aspirated? Why?
- foreign bodies usually aspirated into the right main bronchus- the right bronchus is shorter and wider and also more vertically oriented than the left
True or false: The carina is usually positioned right of the median plane.
FALSE. The carina is usually left of the median plane.
Is the esophagus anterior or posterior to the trachea? Where does it pierce the diaphragm? What does it empty into?
- esophagus is immediately posterior to the trachea- pierces the diaphragm at the esophageal hiatus at T10- empties into the stomach
True or false: The esophagus is typically collapsed anterior to posterior.
true
What is a hiatal (hiatus) hernia?
the stomach herniaes through the esophageal hiatus
What are the two types of hiatal hernias? Describe each (what occurs, which is more common, etc.)
- sliding hiatal hernia: stomach slides freely into the thorax; most common; often asymptomatic2. paraesophageal hernia: fundus goes through the hiatus; often fixed in the position, risking the gastric blood supply
The retropharyngeal space is located between what 2 fascial layers?
the alar layer of prevertebral fascia and the buccopharyngeal fasica
What is the alar layer of the prevertebral fascia?
the anterior layer of the prevertebral fascia
What is the “danger space”?
the space between the alar part of the prevertebral fascial layer and the prevertebral part of the prevertebral fascial layer
True or false: An infection in the retropharyngeal space cannot spread to the danger space.
FALSE. An infection may spread from the retropharyngeal space into the danger space.
What are the contents of the posterior mediastinum?
- esophagus and esophageal plexus- azygos system of veins- descending aorta- thoracic duct- thoracic splanchnic nerves
What are the origin of the fibers of the greater thoracic splanchnic nerves? To what ganglion does the greater splanchnic nerve travel?
T5-T9(10); celiac ganglion
What nerves make up the esophageal plexus? Which forms the anterior vagal trunk and which forms the posterior vagal trunk? What is the reason for this orientation?
- left and right vagus nerves along with sympathetics- left vagus nerve forms the anterior vagal trunk and right vagus nerve forms the posterior vagal trunk- due to rotation of the gut during development
What is the purpose of the azygos system of veins?
provides venous drainage for the thorax
What does the azygos vein drain? Where does it drain to?
- azygos vein drains intercostal veins from the right side of the thorax- arches over the right superior bronchus to drain into the SVC
What does the hemiazygos and accessory hemiazygos veins drain? Where do they drain to? Which is superior and which is inferior?
- hemiazygos and accessory hemiasygos veins drain the left thorax- both drain to the azygos vein- the accessory hemiazygos vein is superior and the hemiazygos vein is inferior (think alphabetical order!)
Does the descending aorta lie to the left or right of the esophagus? What arteries does it give rise to?
- lies just left of the esophagus- gives rise to the posterior intercostal arteries as well as supplies branches to the trachea, bronchi, and esophagus
Between what structures does the thoracic duct travel? How does it pass through the diaphragm?
- thoracic duct travels posterior to the esophagus and anterior to the vertebral bodies; located between azygos vein and descending aorta- passes through the diaphragm with the descending aorta
Where does the thoracic duct enter the venous system?
enters venous angle between the left subclavian vein and left internal jugular vein
What is chylothrax? How can this occur? Is this visible on chest films?
- chylothorax: accumulation of lymph in the pleural cavity- results from a torn or leaking thoracic duct often from lymphoma or trauma during thoracic surgery- a type of pleural effusion is visible on chest films
Are the thoracic splanchnic nerves sympathetic or parasympathetic?
sympathetic
True or false: The thoracic splanchnic nerves innervate the thorax.
FALSE. The thoracic splanchnic nerves innervate the abdomen.
How do the thoracic splanchnic nerves pierce the diaphragm? Which is most medial? Most lateral?
- pass posterior to the diaphragm under the medial arcuate ligament or through the crura of the diaphragm; trunks are covered with parietal pleura- most medial: greater splanchnic nerve- most lateral: least splanchnic nerve
What are the origin of the fibers of the lesser thoracic splanchnic nerves? To what ganglion does the lesser splanchnic nerve travel?
T10-T11; aorticorenal ganglion
What are the origin of the fibers of the least thoracic splanchnic nerves? To what plexus does the least splanchnic nerve travel?
T12; renal plexus
What is the origin of the sympathetic nerves of the thorax? The parasympathetic? What are the 3 plexuses that they form?
- sympathetic: originate from T1-T5- parasympathetic: originate from CN X- commingle to form the cardiac, pulmonary, and esophageal plexuses
True or false: The esophagus is typically collapsed anterior to posterior.
true
