UNIT 4: The heart Flashcards
Give an overview of the position and sections of the mediastinum.
Located between the two pleural cavities within the thoracic cage.
Starts at the thoracic inlet and ends at the diaphragm.
T4/5 divides into the superior and inferior mediastinum
THe inferior can then be split into the anterior, middle and posterior, with the middle consisting of other pericardial sac and the heart.
What is the largest section of the mediastinum?
The middle.
What is the pericardium?
Found within the mediastinum.
Is the covering of the heart.
Consists of the viseceral and parietal serous membrane, and an outer fibrous pericardium.
What does the fibrous pericardium attach to?
Fuses superiorly with the roots of the great vessels, fuses inferiorly with the diaphragm.
Anteriorly is connected to by the sternopericardial ligaments.
What two layers is the pericardial cavity between?
Is a small cavity containing fluid, located between the parietal and visceral pericardium.
WHat are pericardial sinsues?
Where are they located?
What causes them to form?
Pericardial sinuses are potential spaces within the pericardium.
The visceral and parietal pericardium layers are often separate but a points they fuse together such as around the great arteries then again around the great veins.
Sinuses are the cavities created between these fusions.
The transverse sinus is between the the great arteries and the great veins.
The oblique sinus is found posterior and superiorly to the apex of the heart, as is holding the heart from the back.
What is pericarditis?
Inflammation of the pericardium
What is cardiac tamponande?
When fluid builds up in the pericardial cavity, exerts pressure on the myocardium.
Fbrous pericardium is unable to expand to cope with the extra fluid.
Symptoms include decreased cardiac output, hypotension and tachycardia, may also have difficulty breathing.
What are the different great vessels?
Inferior vena cava
Superior vena cava (L+R brochicephalic, jugular and subclavian)
Pulmonary veins (4)
Pulmonary trunk
Ascending aorta and its arch (gives of the brachiocephalic, left common carotid and left subclavian).
What does the brachiocephalic artery trunk bifuracte into?
The right common carotid and the right subclavian artery.
What is the ligamentum arteriosum?
Ligament connecting the pulmonary trunk to the arch of the aorta.
Left over from a foetal feature doctus arteriosum which allowed blood to bypass the lungs during foetal development as blood was oxygenated by the mother.
What is the coronary sinus?
A collection of cardiac veins on the posterior surface of the heart, mainly made from the widening of the great cardiac vein.
How can doexygenated blood enter the right atrium?
Superior vena cava
Inferior vena cava
The coranry sinus.
What are the internal features of the right atrium?
Derived from two different embryological structures, the boundary between these features is shown in adults as a thick muscular ridge known as the crista terminalis.
Anterior to this are walls of muscular ridges known as musculi pectinati.
Posterior to this are smooth walls, contains the fossa ovali.
What is the fossa ovalis?
Marks the embryological location of the foramen ovale, allowed blood to bypass the lungs.
The fossa is found in the adults rights atrium
The valve is found in the adults left atrium
