Heart Flashcards
Where is the mediastinum?
Medial to lungs from the T2 to T12 vertebrae
Where does the heart sit?
In the middle portion of the inferior mediastinum
Between the second rib and fifth intercostal space
Base of heart
Superior; Where blood vessels attach at
Points to right shoulder
Apex of heart
Inferior pointed area of heart
Points to left hip
Why is the heart in the thorax?
Brain grows fast which causes head to bend under embryos body which leads to the heart in the thorax ❤️
What are the layers of the heart?
Pericardium
Myocardium
Endocardium
Fibrous pericardium
Superficial layer of heart
Pericardium
Superficial layer that protects, anchors, and allows for friction free movement
Myocardium
Middle muscle layer that contracts/ moves
How is cardiac muscle tissue arranged?
In circular or spiral patterns
This creates chambers
Cardiac Muscle cells description
Short and branched
Myofibrils
One nucleus
Intercalated Discs
Endocardium
Deep protective layer
Allows for blood to move through the heart without any resistance
What lines the internal walls of the heart?
The endocardium
Right side of the heart
Pulmonary Circuit
Lungs
Left side of the heart
Systemic Circuit
Body systems
What are the superior chambers of the heart called?
Atria/ atrium
Where do atria recieve blood from?
From the Pulmonary and systemic circuits through veins
Right atrium
Blood enters from Vena Cava + coronary sinus
Fossa ovalis ; remanent of the foramen ovale of fetal heart
Left atrium
Blood enters from pulmonary veins
Where does blood from the lungs flow back into?
The left atrium
Interatrial septum
Myocardium layer that seperates the right and left atria
Arteries move blood ___ from the heart and veins bring it ____
Away, In
What are ventricles?
The exit or pumping chambers of the heart
Blood moves out of the arteries
Right ventricle
Blood exits out of the pulmonaru trunk and to the pulmonary circuit
Left Ventricle
Blood exits out of the aorta to the systemic circuit
includes the apex
Interventricular septum
seperates the right and left ventricles
Auricles
Folded extensions on external surface of atria
Function of auricles
Increased blood volume that atria can contain
Interventricular sulci
Depressions that seperate the ventricles and contain blood vessels
Anterior and superior
Pectinate muscles
irregular internal ridges of atrial myocardium
Trabeculae carnea
irregular internal ridges of the ventricular myocardium
papillary muscles
large muscular projections into the ventricular cavity
What do papillary muscles do?
They anchor the tendon cords of the AV valves to the walls of the heart
How does the heart develop?
Starts off as two tubes that fuse to become one
Four bulges form
Heart bends causing atria to be superior and ventricles to be inferior
interventricular septum forms along midline of heart which creates a left and right side
Why does the interatrial septum remain open at the foramen ovale?
Allows for oxygen- rich blood to bypass pulmonary circuit
