HUMAN ANATOMY &
PHYSIOLOGY (BIOL 235)
Comprehensive Lecture
Notes (with all information
you need to pass)
ATHABASCA UNIVERSITY
,20.1 Anatomy of the Heart
Location of the Heart
Heart
▪ Roughly same size as closed fist.
▪ 250 g (Females), 300 g (males).
▪ Rests on the diaphragm, near midline of thoracic cavity.
Heart Surfaces (7):
1. Mediastinum
▪ Anatomical region from sternum to vertebral column, from 1st rib to diaphragm, and
between lungs.
2. Apex
▪ Tip of the left ventricle (lower left chamber of heart), and rests on diaphragm.
3. Base
▪ Opposite of the apex and posterior. Formed by atria (upper chambers), mostly the left
atrium.
4. Anterior Surface
▪ Deep to sternum and ribs.
5. Inferior Surface
▪ Between apex and right surface; rests on the diaphragm.
6. Right Surface
▪ Faces right lung, from inferior surface to base.
7. Left Surface
▪ Faces left lung, from base to apex.
, Pericardium
Pericardium
▪ Membrane that surrounds and protects the heart.
▪ Confines the heart in position of mediastinum, while allowing movement for contraction.
▪ Two main parts: (1) Fibrous pericardium, (2) Serous pericardium.
Fibrous Pericardium
▪ Superficial part
▪ Inelastic, dense irregular tissue.
▪ Prevents overstretching, protection, and anchors heart to mediastinum.
Serous Pericardium
▪ Deeper, thinner, more delicate membrane that forms a double layer around the heart.
▪ Two layers:
o Parietal layer: fused to fibrous pericardium.
o Visceral layer (epicardium): one of the layers of heart wall, and adheres to the surface
of heart.
o Pericardial Cavity: the space between parietal and visceral layer.
o Pericardial fluid: thin film of lubricating fluid by pericardial cells.
Layers of the Heart Wall
Epicardium (External)
▪ Contains two tissue layers: visceral layer of serous pericardium and fibroelastic/adipose tissue
layer.
▪ Smooth, slippery texture of outer surface of heart.
▪ Contains blood vessels that supply the myocardium.
Myocardium (Middle)
▪ Composed of cardiac muscle tissue; makes up 99% of the heart wall.
▪ Responsible for pumping action of the heart.
Endocardium (Inner)
▪ Thin layer of endothelium and connective tissue.
▪ Provides smooth lining for chambers of the heart.
▪ Covers valves of heart.
PHYSIOLOGY (BIOL 235)
Comprehensive Lecture
Notes (with all information
you need to pass)
ATHABASCA UNIVERSITY
,20.1 Anatomy of the Heart
Location of the Heart
Heart
▪ Roughly same size as closed fist.
▪ 250 g (Females), 300 g (males).
▪ Rests on the diaphragm, near midline of thoracic cavity.
Heart Surfaces (7):
1. Mediastinum
▪ Anatomical region from sternum to vertebral column, from 1st rib to diaphragm, and
between lungs.
2. Apex
▪ Tip of the left ventricle (lower left chamber of heart), and rests on diaphragm.
3. Base
▪ Opposite of the apex and posterior. Formed by atria (upper chambers), mostly the left
atrium.
4. Anterior Surface
▪ Deep to sternum and ribs.
5. Inferior Surface
▪ Between apex and right surface; rests on the diaphragm.
6. Right Surface
▪ Faces right lung, from inferior surface to base.
7. Left Surface
▪ Faces left lung, from base to apex.
, Pericardium
Pericardium
▪ Membrane that surrounds and protects the heart.
▪ Confines the heart in position of mediastinum, while allowing movement for contraction.
▪ Two main parts: (1) Fibrous pericardium, (2) Serous pericardium.
Fibrous Pericardium
▪ Superficial part
▪ Inelastic, dense irregular tissue.
▪ Prevents overstretching, protection, and anchors heart to mediastinum.
Serous Pericardium
▪ Deeper, thinner, more delicate membrane that forms a double layer around the heart.
▪ Two layers:
o Parietal layer: fused to fibrous pericardium.
o Visceral layer (epicardium): one of the layers of heart wall, and adheres to the surface
of heart.
o Pericardial Cavity: the space between parietal and visceral layer.
o Pericardial fluid: thin film of lubricating fluid by pericardial cells.
Layers of the Heart Wall
Epicardium (External)
▪ Contains two tissue layers: visceral layer of serous pericardium and fibroelastic/adipose tissue
layer.
▪ Smooth, slippery texture of outer surface of heart.
▪ Contains blood vessels that supply the myocardium.
Myocardium (Middle)
▪ Composed of cardiac muscle tissue; makes up 99% of the heart wall.
▪ Responsible for pumping action of the heart.
Endocardium (Inner)
▪ Thin layer of endothelium and connective tissue.
▪ Provides smooth lining for chambers of the heart.
▪ Covers valves of heart.
