Mediastinum and the Heart Flashcards
Where is the mediastinum
Between right and left lungs, Superior thoracic aperture and diaphragm
Divisions of mediastinum?
Superior and inferior
Where does the mediastinum divide?
Transverse sternal angle plane
What does the mediastinum contain?
Thymus, heart, great vessels, trachea/bronchi, esophagus, thoracic duct, etc.
Where is the transverse thoracic plane at the sternal angle?
T4 disc
Somatic pericardial cavity does what?
fixes heart to central tendon of diaphragm
visceral pericardium is also known as what?
epicardium
What do the pericardium do?
lubricate for smooth movement of heart in the cavity
What are the somatic pericardiums?
fiberous pericardium and parietal pericardium
Cardiac wall has what three layers?
Epicardium, myocardium, endocardium
Epicardium is somatic. True or false?
False. This is a visceral pericardium.
Myocardium is for what?
cardiac muscles
The heart is shaped like a _____
cone
Where is the apex of the heart in relation to ribs?
The left 5th intercostal space
What is the base of the heart?
Left atrium
What is the right pulmonary surface of the heart?
right atrium
What is the left pulmonary surface of the heart?
Left ventricle
Right heart (right ventricle and atrium) has ____ oxygen blood
low oxygen blood
Left atrium and ventricle have _____ oxygen blood
high oxygen blood
Which two sinuses are important surgical landmarks?
The oblique pericardial sinus and the transverse pericardial sinus
What are the two veins that are great cardiac vessels?
Superior vena cava, pulmonary veins
What two arteries are great cardiac vessels?
Pulmonary trunk and ascending aorta to aortic arch
Which of the following structures can be seen on transverse CT scans at the sternal angle?
T4 disc
What does the right atrium contain?
Auricle, crista terminalis, fossa ovalis, openings of SVC and IVC, opening of coronary sinus, tricuspid valve
What does the right ventricle contain?
Trabeculae carneae, papillary muscles, Anterior/Posterior/Septal valve, Pulmonary valves
What does the left atrium contain?
Auricle, 4 or more pulmonary veins, fossa ovalis, left AV valve (bicuspid)
Which intercostal space does the apex of the heart point to?
Left 5th intercostal space
What does the left ventricle contain?
Trabeculae carneae, papillary muscles, Anterior/posterior valve (bicuspid), aortic valves
Where are the pulmonary and aortic valves located?
Between the ventricles and the great arteries
What are the AV valves?
Tricuspid and bicuspid
What is the function of the valves in the heart?
Prevention of blood backflow
where do you auscultate for the aortic valve?
right second intercostal space
where do you auscultate for the pulmonary valve?
Left 2nd intercostal space
Where do you auscultate for the tricuspid valve?
5h intercostal space lateral to sternum
Where do you auscultate for the mitral valve?
5th intercostal space, mid-clavicular line
Where does moderate/septomarginal band locate and connect which structures? Why is it important?
right ventricle connects to papillary muscles, assists in valve opening and closure at same time
What is the goal of pulmonary circulation
exchange of CO2 and O2
Where does pulmonary circulation flow?
Right atrium
Right ventricle
Pulmonary trunk
Right and left pulmonary arteries
Right and left lungs
Right and left pulmonary veins
Left atrium: high oxygen
what is the goal of systemic circulation?
delivery of O2 and nutrition to whole body
Do pulmonary and systemic circulation take place simultaneously?
yes
Does systemic circulation include the lungs?
Yes
what structure in systemic circulation is in charge of nutrition?
Liver
What structure in systemic circulation is in charge of waste?
Kidneys
What are the right Coronary arteries?
Nodal branch, marginal branch, posterior interventricular artery
What are the left coronary arteries?
Anterior interventricular arteru/ left anterior descending artery
circumflex branch
Venous drainage follows which pathway?
Great cardiac vein to middle cardiac vein to small cardia vein to coronary sinus to right artium
What veins directly drain into right atrium?
anterior cardiac veins
What is the cardiac cycle?
beginning one one heartbeat to beginning of next
What happens in diastole?
Open AV valves, close pulmonary/aortic valves
negative pressure causes blood to drain into ventricles
What happens in systole?
Open pulmonary/aortic valves, close AV valves
atria contact to drain more blood into the ventricles, then ventricular contraction to project blood to lungs and whole body
SA node base heart rate?
80~100 BPM
AV node base heart rate?
40~60 BPM
Conduction system of heart:
SA node to AV node to Bundle of His to right and left bundle branches to purkinje fibers to cardiac muscles
Sympathetic intrinsic innervation of the heart does what?
Increases heart rate.
What are the sympathetic nerves of the heart?
Cervical cardiac sympathetic nerves and thoracic cardiac sympathetic nerve
What provides parasympathetic innervation of the heart?
Vagus nerve
Vagus nerve does what to heart rate?
Decreases
What are the branches of the vagus nerve?
Cervical cardiac, thoracic cardiac, left vagus nerve, and right vagus nerve
What is the left vagus nerve responsible for?
Recurrent laryngeal nerve = why we are able to speak
Where can patients sometimes feel referred pain after heart surgery?
Right shoulder from the c4 dermatome
How many patients have right bicipital groove pain
1 in 1000
What does the umbilical vein do?
takes high oxygen blood from placenta through liver for nutrient stoarge and detoxification
What forms when umbilical vein closes after birth?
Ligamentum teres/ round ligament
Which nerve provides parasympathetic support for the heart?
Vagus nerve
What causes heart burn?
Gastroesophogeal reful, cardiac notch of stomach causes us to feel it in heart area
What structure has impressions on both lungs?
Esophagus
What is the largest lymphatic channel?
Between azygos vein and esophagus
What percentage does the thoracic duct drain?
75% of body lymph fluid
What provides the innervation for the three cavities?
Splanchnic nerve: preganglionic axons to form synapses in prevertebral ganglion
Greater splanchnic nerve: T5~T9
Lesser splanchnic nerve: T10~T11
Least splanchnic nerve: T12
Lumbar/sacral splanchnic nerve: L1~L2
Which fetal structures degenerate to form the ligamentum arteriosum and ligamentum venosum?
ductus venosus and ductus arteriosus
Where does thoracic duct deliver the contents into blood circulating system?
left subclavian and internal jugular veins
