Thoracic Cavity Flashcards
If you had to insert a chest tube into someones 8th intercostal space, where would you insert the needle?
Above the margin of the 9th rib
What is another name for parietal pleura?
Mediastinal pleura
What are the two divisions of the mediastinum?
Which division has subdivisions and what are they?
Superior and inferior
Inferior has 3 subdivisions: anterior, middle, and posterior
- Where does superior mediastinum end (inferiorly)?
- Superficial contents of the superior mediastinum?
- Middle contents of the superior mediastinum?
- Posterior contents of the superior mediastinum?
- Sternal angle anteriorly to lower border of T4 posteriorly
- Thymus, left and right brachiocephalic vein and superior vena cava
- Aortic arch (and 3 branches), phrenic nerve and vagus nerve
- Trachea, esophagus, and thoracic duct
INFERIOR MEDIASTINUM
- Inferior mediastinum runs behind where?
- Contents of anterior mediastinum?
- Contents of middle ?
- Contents of posterior?
- The lower 8 thoracic vertebrae
- Fat, remnants of thymus gland, anterior mediastinal lymph nodes
- Heart and pericardium, beginning or termination of great vessels, phrenic nerve, pericardiacophrenic vessels, lymph nodes
- Esophagus, vagus nerve, thoracic aorta, azygos system of veins, thoracic duct, thoracic sympathetic trunk, and posterior mediastinal lymph nodes
Each pleura has two parts, what are they?
What are these two pleuras separated by?
Pleural cavity contains?
Parietal layer and visceral layer
Separated from one another by a slitlike space called pleural cavity (pleural space)
Pleural fluid to permit the 2 layers to move on each other with minimum friction
What is the costophrenic recess?
~ not to get confused with the costodiaphragmatic recess
A regional division of parietal pleura; it is the lower area of the pleural cavity into which the lung expands on inspiration
Where is the Costodiaphragmatic recess ?
Function?
Slitlike spaces between the costal and diaphragmatic pleura that is separated only by a capillary layer of pleural fluid
During inspiration, lower margins of the lungs descend into the recess; during expiration, lower margins of the lungs ascend so that the costal and diaphragmatic pleurae come together again
Clinical significance relating a pleural effusion?
If you have a pleural effusion, lungs can be completely displaced from this space
- Parietal pleura is sensitive to what?
- Costal pleura is innervated by?
- Mediastinal pleura is innervated by?
- Diaphragmatic pleura is innervated by?
- Pain, temperature, touch, and pressure
- Intercostal nerves
- Phrenic nerve
- Phrenic nerve (over domes) and lower 6 intercostal nerves (around the periphery)
Two surfaces of the lungs?
Costal surface (corresponds to chest) and mediastinal surface (contains a depression called hilum in the middle)
Significance of the hilum?
Hilum is in the middle of the mediastinal surface of the lungs and the bronchi, vessels and nerves that form the root enter and leave through the hilum
Which is thicker: the anterior or posterior border of the lung?
Posterior border is thicker
How many lobes do each lung have?
Name the fissures of the lobes
Right lung has 3 lobes; left lung has 2 lobes
Right lobe has oblique and horizontal fissures; left lobe has oblique fissure
If you lose a lung, or lose a section of a lung what happens?
The remaining/intact lung will hypertrophy. When just looking at this and not knowing, you might think it is a disease condition but in reality, it is just compensating for the other lung
Trachea branches off to … (give all divisions)
Trachea -> left and right principal bronchus -> lobar bronchus -> segmental bronchus -> terminal bronchiole -> alveoli
Each segmental bronchus passes to an independent unit of a lung lobe called ?
Bronchopulmonary segement; once segemental bronchus enters this, it will divide repeatedly
Since bronchopulmonary segment is its own structural unit, what two characteristics does it have?
It contains arteries, lymph vessels, nerves, and veins and it can be removed surgically is disease is detected
- Root of lung has structures that are?
- What structures make up the root of the lung?
- Root is surrounded by pleura that joins what two pleuras?
- Entering or leaving the lung
- Bronchi, pulmonary arteries/veins, lymph vessels, bronchial vessels, and nerves
- Joins the mediastinal pleura and the visceral pleura covering the lungs
- Blood supply of the bronchi, connective tissues of the lung, and the visceral pleura?
- Bronchial vein drains into?
- Two pulmonary veins leave each lung root to empty into?
- Bronchial artery branches of thoracic aorta
- Azygos and hemiazygos vein
- Left atrium
Nerve supply of lungs?
Pulmonary plexus composed to autonomic nerve fibers of sympathetic and parasympathetic from vagus nerve
- Sympathetic efferent fibers have what two effects?
2. Parasympathetic efferent fibers?
- Bronchodiltation and vasoconstriction
2. Bronchoconstriction and vasodilatation and increased glandular secretion
- Lymphatic drainage of lung themselves goes through which node? Then..
- All lymph from lung leaves hilum and drains into? Then…
- Where does it go after this?
- Bronchopulmonary nodes
- Tracheobronchial nodes
- Bronchomediastinal trunk and to thoracic duct, right lymphatic duct, or brachiocephalic veins
Function of the pericardium?
Pericardium location?
Restrict excessive movements of the heart as a whole and to serve as a lubricated container in which different parts of the heart can contract
Lies within the middle mediastinum
Two layers of the pericardium and their function?
One of these layers has two subdivisions, what are they?
Fibrous layer (protection) and serous layer (transport membrane)
Serous layer: parietal and visceral
- Main function of the outer, fibrous layer of pericardium?
2. Name 5 things that pierce the fibrous layer superiorly and why it is significant?
- Protects heart against sudden overfilling
2. Aorta, pulmonary trunk, and SVC, IVC and pulmonary veins; becomes fused with tunica adventitia of these vessels
Location of the parietal and visceral layers of the serous layer of the pericardium
Parietal layer lines the fibrous pericardium and becomes continuous with the visceral layer around the roots of great vessels
Visceral layer reflected onto the heart (often called the epicardium - external layer of the heart wall)
Where is the pericardial cavity?
Function?
Lies between the parietal and visceral layer of the serous layer of the pericardium
Contains a thin film of serous fluid which helps in frictionless movement of the heart
Structure/function of the pericardial sinuses:
- Transverse sinus
- Oblique sinus
- Posterior to ascending aorta/pulmonary trunk and anterior to SVC; communicates with the main part of pericardial cavity at its right and left ends
- (Inverted U shaped) posterior to the left atrium; produced by reflection of pericardium onto pulmonary veins and IVC
~ These are very close to each other, transverse is superior and anterior~
What innervates the following:
- Fibrous pericardium
- Parietal pericardium
- Visceral pericardium
- Phrenic nerve
- Phrenic nerve
- Sympathetic trunk; parasympathetic fibers of vagus nerve
What is the arterial supply to the following:
- Fibrous pericardium
- Parietal pericardium
- Visceral pericardium
- Pericardiophrenic artery, musculophrenic artery, and pericardial branches of bronchial, esophageal, and superior phrenic arteries
- Same as 1.
- Coronary arteries
Pericardiophrenic veins drain into ?
The internal thoracic vein
Pericardiocentesis and intracardial injections are given where?
Through the 5th and 6th intercostal space near the sternum (area of cardiac notch)
- What is cardiac tamponade?
2. What physiological effect will it have on the heart?
- Pericardial cavity is normally a potential space with a thin layer of fluid for lubricant; cardiac tamponade is accumulation of fluid in this space
- Progressively reduced ventricular filling (medical emergency)
Location of the heart?
Within the pericardium in the mediastinum
The following surfaces of the heart are formed mainly by which parts of the heart and what separates said two parts:
- Sternocostal surface
- Diaphragmatic surface
- Base (posterior) surface
- Right atrium and right ventricle; separated by vertical atrioventricular groove
- Right and left ventricle; separated by posterior interventricular groove
- Formed by left atrium (into which open 4 pulmonary veins)
- In anatomical position of the heart, what is anterior and what is posterior?
- What forms most of the inferior surface of the heart?
- Pulmonary veins enter left atrium in what direction?
- Ventricles are anterior; Atria are posterior
- Right ventricle
- Horizontal
- Apex of the heart is formed by?
- Location of apex?
- Clinical significance of location?
- Left ventricle
- Posterior to the 5th intercostal space, just medial to the left midclavicular line
- Position can help determine if patient has cardiomyopathy or cardiomegaly
- Atria are ___ chambers; ventricles are ___ chambers
- Which side is more anterior: right or left
- Which chamber has a higher pressure?
- Receiving; pumping
- Right atrium and ventricle are anterior to the left atrium and ventricle
- Left chamber- systemic circulation (right chamber is responsible for pulmonary circulation)
What will happen clinically if aortic valve has regurgitation?
The blood will flow back into the left ventricle leading to less systemic blood circulation; this will cause distension and thereby muscles will extend and become weakened (dilated cardiomyopathy)
2 functions of the fibrous skeleton the heart
Separates atrial and ventricular myocardia to block the spread of excitation across the atrioventricular border (coronary sulcus) and supports all 4 heart valves by anchoring rings
5 components of the intrinsic conduction system (nodal system)
Sinoatrial node, atrioventricular node, atrioventricular bundle, bundle branches and purkinje fibers
SA node location and function
Right atrium; starts each heart beat and sets rate
AV node location and function
Left atrium (lower part of atrial septum just above attachment of tricuspid valve)
Cardiac impulse is conducted from it to the ventricles
Explain the AV bundle divisions
At the upper border of septum, the atrioventricular bundle divides into two branches: RBB and LBB (one for each ventricle)
RBB passes down right side of ventricular septum and becomes continuous with purkinje plexus of right ventricle
LBB pierces the septum and passes down on its left side beneath the endocardium. Usually divides into two branches (anterior and posterior) and eventually becomes continuous with purkinje fibers of left ventricle
- What arteries supply the heart?
2. Where do these arteries aride from?
- Right and left coronary arteries
2. Ascending aorta immediately above the aortic valves
What arteries supply the following parts of the conducting system:
- SA node
- AV node/AV bundle
- RBB
- LBB
- Right (and occasionally left ~35%) coronary artery
- Right coronary artery
- Left coronary artery
- Right and left coronary arteries
In most people (90%) the right coronary artery gives off the _____ artery
Posterior interventricular artery
Most of the blood in the heart drains?
Into the right atrium through the coronary sinus (continuation of the great cardiac vein)
Surface anatomy of heart valves:
- Tricuspid valve
- Mitral valve
- Pulmonary valve
- Aortic valve
- Behind right half of sternum; opposite the 4th intercostal
- Behind left half of sternum; opposite 4th costal cartilage
- Behind medial end of the third left costal cartilage
- Behind the left half of sternum; opposite the 3rd intercostal space
Extent of the trachea?
From 6th cervical vertebra to IVD between 4th and 5th thoracic vertebra
Trachea moves in what direction during expiration and inspiration?
Trachea bifurcation rises during expiration, lowers during inspiration
How does trachea stay open?
What is located at C6
U shaped rings of hyaline cartilage embedded in the wall
Cricoid cartilage
Blood supply of trachea
Upper 2/3 = inferior thyroid arteries
Lower 1/3= bronchial arteries
Lymph drainage of trachea?
Pretracheal and paratracheal lymph nodes and deep cervical nodes
Nerve supply of trachea
Sensory = vagi and recurrent laryngeal nerves
Sympathetic nerves supply the trachealis muscle
Name the trachea bifurcations (what they divide into)
Where is the location of the bifurcation of the trachea?
Trachea -> primary bronchi -> terminal bronchioles -> respiratory bronchioles -> alveolar ducts -> alveolar sacs -> alveoli
Trachea bifurcates at T4/T5
Main difference between terminal bronchioles and respiratory bronchioles?
Terminal just allow for passage of air; respiratory allow for gas exchange
Purpose of surfactant?
What helps babies lungs mature?
What will happen if baby is born with no surfactant?
Helps break up surface tension
Giving mother steroids
Respiratory distress syndrome
- Difference between right and left primary bronchi
- What does right bronchus give off?
- What does left bronchus give off?
- Right is wider, shorter, and more vertical than left
- Superior lobar bronchus before entering hilum; once it enters hilum it divides into middle and inferior lobar bronchus
- Superior and inferior lobar bronchus (upon entering the hilum of left lung)
