Thorax Part 2 Flashcards
What does the thoracic cavity include?
2 pulmonary cavities – lungs and pleura with one central compartment of the mediastinum
Where is the mediastinum?
T4/T5 (sternal angle)
What does the mediastinum divide into?
superior and inferior parts
What is located in the superior mediastinum?
4 arteries: arch of aorta, brachiocephalic, left common carotid, left subclavian
4 nerves: R&L vagus and phrenic nerves
3 veins: R&L brachiocephalic, SVC
trachea & esophagus, thymus, thoracic duct
What is the inferior mediastinum divided into?
MAP - middle, anterior, posterior
What is in the posterior mediastinum?
4th-12th thoracic vertebrae, includes descending aorta, axygos0hemiazygos veins, lymphnodes, thoracic duct
What is in the anterior mediastinum?
thymus and lymph nodes
What are the boundaries of the anterior mediastinum?
superior horizontal plane, inferior diaphragm, anterior body & xiphoid process, posterior heart
What is included in the middle mediastinum?
heart, pericardium, ascending aorta, L&R main bronchi, tracheal bifurcation , vena cava, R&L pulmonary veins and phrenic nerves, lymph nodes
What is the steps of surface to deep of the thoracic duct?
thymus -> veins -> arteries -> nerves -> trachea -> esophagus -> thoracic duct
What does the vagus nerve branch off into?
left recurrent laryngeal nerve
Where is a mediastinoscopy?
superior and middle mediastinum staging
What are the two pleural layers with a cavity in between?
visceral (can’t differentiate), parietal (sensitive to pain, temp, touch, adhering to mediastinum versus not). Parietal attaches to chest wall and visceral is against organs
What is the pleural cavity?
between parietal and visceral layers; contains pleural fluid for lubrication of lungs to inhale and exhale
What are recesses?
area between visceral and parietal where lungs can expand
How many lobes does the right lung have?
- larger.
How many lobes does the left lung have?
2, cardiac notch, lingula - tongue like process off left
What divides the lungs into lobes?
fissures
What is the pulmonary innervation?
cardiac plexus and vagus nerve
How are the lungs nerve supplied?
pulmonary plexi
Where is the sympathetic innervation of the thorax?
T1-L2/L3
gray – to spinal cord
white – from spinal cord
Where is the parasympathetic innervation?
cranial and S2-S4; rest and digest…key=R&L vagus nerves
What does the parasympathetic stimulation cause?
vasodilation and bronchoconstriction
How many pulmonary veins are there?
2 on each side for 4 total
Where does the pulmonary artery deliver blood to?
lungs
Where does the pulmonary veins deliver blood to?
heart
What is the hilum?
pulmonary blood vessels enter and leave through here, with a primary bronchus on each side. Two pulmonary arteries, four pulmonary veins
What is a pulmonary embolus?
DVT travels to the heart lodging itself in the pulmonary arteries; FATAL issue
Where is the carina of the bronchi?
at sternal angle
What is the bronchial’s blood supply?
left bronchial arises from thoracic aorta
right bronchial arises from posterior intercostal arteries (5/6 posterior intercostal artery)
How does the bronchi drain?
right vein = azygous
left vein = hemi-azygous vein
deep = deep lung parenchyma and drain into pulmonary veins
Where is the azygous vein?
Deep on right side of body, originates at 12th thoracic vertebrae and branches over hilum and joins SVC
What is the azygous vein’s job?
transports deoxygenated blood from posterior thorax and abdomen into superior vena cava
Where is the hemiazygos?
T9 from left renal
Where is the accessory hemazygous?
T8 drains into azygous, drains left superior hemithorax
What is the drainage process of the azygos venous process?
hemiazygous–>azygous–> SVC, entering through the aortic hiatus
What is an azygous lobe?
during embryo development, M>F, 1% of people have an extra little lobe with displaced azygous vein that creates another fissure (no bronchus though)
What are types of alveoli?
type I 95% and type II 5% (infants need extra of this pulmonary surfactant to keep tension and alveolis from collapsing)
What is respiratory distress syndrome?
apnea, cyanosis, grunting, inspiratory stridoer, nasal flaring, poor feeding….common in preterm neonates, prevents alveoli collapse with pulmonary surfactant
What is the blue bloater?
chronic bronchitis common with overweight, cyanotic, edema, wheezing, smokers
What is the pink puffer?
old and thin, dyspnea, quiet chest
What is the innervation of the middle mediastinum?
pericardiacophrenic artery and phrenic nerve c3-c5, vagus nerve
What is the pericardium?
very thick sack that makes up two layers that surround the heart
What are the layers of the pericardium?
fibrous (anchor, prevents heart from filling with excess blood) and serous (inner layer)
What are the three heart layers?
epicardium (outer/visceral), myocardium (muscular wall of the heart), endocardium (covers inner surface of heart)
What is a cardiac tamponade?
emergency medical condition fluid buildup of pericardial sac that prevents refilling of ventricles
What is Beck’s triad for a cardiac tamponade?
hypotension, jugular venous distension, muffled heart sounds. Treated with needle asperation along left sternal border of 5th intercostal space
This is a reminder to review your heart anatomy ! What is the flow?
SVC/IVC -> right atrium -> tricupsid valve -> right ventricle -> pulmonary valve -> pulmonary artery -> lungs -> left atrium -> bicupsid/mitral valve-> left ventricle -> aortic valve -> aorta -> rest of body
What is the patent foramen ovale?
hole between right and left atrium while in womb..this and ductus arteriosus will close normally after birth (bypassing lungs, using mom’s body)
What are the five fetal adaptions?
umbilical vein (placenta O2 rich blood –> liver –> IVC)
ductus venosus (umbilical vein to IVC)
patent foramen ovale (hole RA->LA)
ductus arteriosus (direct connection between pulmonary and aorta)
umbilical arteries (blood leaves aorta, majority diverted back to placenta)
