Heart Anatomy:
● Location:
○ Snugly enclosed within the middle mediastinum (medial cavity of thor
ax)
■ Contains the heart, pericardium, vessels to & from the heart &
lungs, trachea & esophagus.
■ M.Mediastinum – located in the inferior mediastinum (lower th
an the sternal angle)
○ Extends obliquely from 2nd rib → 5th intercostal space.
○ Anterior to Vertebrae
○ Posterior to Sternum
○ Flanked by 2 lungs
○ Rests on the diaphragm
○ 2/3 of its mass lies to the LHS of the midsternal line.
● The Pericardium: (Coverings of the Heart)
○ A double-walled sac
○ contains a film of lubricating serous fluid
○ 2 Layers of Pericardium:
■ Fibrous Pericardium:
● Tough, dense connective tissue
● Protects the heart
● Anchors it to surrounding structures
, ● Prevents overfilling of the heart – if fluid builds up
in the pericardial cavity, it can
● inhibit effective pumping. (Cardiac Tamponade)
■ Serous Pericardium: (one continuous sheet with ‘2 layers’)
● Parietal Layer – Lines the internal surface of the fib
rous pericardium
● Visceral Layer – (aka Epicardium) Lines the external h
eart surface
● Layers of the Heart Wall:
○ Epicardium:
■ Visceral layer of the serous pericardium
○ Myocardium:
■ Muscle of the heart
■ The layer that ‘contracts’
○ Endocardium:
■ Endothelium lining the chambers of the heart
■ Prevents clotting of blood within the heart
■ Forms a barrier between the O2 hungry myocardium and the blood.
(blood is supplied via the coronary system)
● Fibrous Skeleton of the Heart:
○ The network of connective tissue fibres (collagen & elastin) within
the myocardium
● Location:
○ Snugly enclosed within the middle mediastinum (medial cavity of thor
ax)
■ Contains the heart, pericardium, vessels to & from the heart &
lungs, trachea & esophagus.
■ M.Mediastinum – located in the inferior mediastinum (lower th
an the sternal angle)
○ Extends obliquely from 2nd rib → 5th intercostal space.
○ Anterior to Vertebrae
○ Posterior to Sternum
○ Flanked by 2 lungs
○ Rests on the diaphragm
○ 2/3 of its mass lies to the LHS of the midsternal line.
● The Pericardium: (Coverings of the Heart)
○ A double-walled sac
○ contains a film of lubricating serous fluid
○ 2 Layers of Pericardium:
■ Fibrous Pericardium:
● Tough, dense connective tissue
● Protects the heart
● Anchors it to surrounding structures
, ● Prevents overfilling of the heart – if fluid builds up
in the pericardial cavity, it can
● inhibit effective pumping. (Cardiac Tamponade)
■ Serous Pericardium: (one continuous sheet with ‘2 layers’)
● Parietal Layer – Lines the internal surface of the fib
rous pericardium
● Visceral Layer – (aka Epicardium) Lines the external h
eart surface
● Layers of the Heart Wall:
○ Epicardium:
■ Visceral layer of the serous pericardium
○ Myocardium:
■ Muscle of the heart
■ The layer that ‘contracts’
○ Endocardium:
■ Endothelium lining the chambers of the heart
■ Prevents clotting of blood within the heart
■ Forms a barrier between the O2 hungry myocardium and the blood.
(blood is supplied via the coronary system)
● Fibrous Skeleton of the Heart:
○ The network of connective tissue fibres (collagen & elastin) within
the myocardium
