Last update:

Heart Wall Anatomy | Structure of the Heart Wall

The image descriptionheart wall is composed of three tissue layers.

Section of the heart wall animation slide 1
Section of the heart wall animation slide 2
Section of the heart wall animation slide 3
Section of the heart wall animation slide 4
Section of the heart wall animation slide 5
Section of the heart wall animation slide 6
Section of the heart wall animation slide 7
Section of the heart wall animation slide 8
Section of the heart wall animation slide 9
Section of the heart wall animation slide 10
Section of the heart wall animation slide 11
Section of the heart wall animation slide 12
Section of the heart wall animation slide 13
Section of the heart wall animation slide 14
A section of the heart wall.
  1. Covering the outer surface of the heart is the image descriptionepicardium. It is also referred to as the visceral pericardium, which is the inner layer of the pericardium.
Section of the heart wall animation slide 14
A section of the heart wall with the epicardium highlighted and the squamous tissue layer, and areolar tissue layer labelled.
The epicardium layer of the heart wall.
1
2

The epicardium is a serous membrane that consists of an external layer of simple squamous and an inner layer of areolar tissue (loose connective tissue). The squamous cells secrete lubricating fluids into the pericardial cavity.

  1. The thick middle layer of the heart wall is called the image descriptionmyocardium. It consists of numerous layers of cardiac muscles fibers that wrap around the heart wall. Contraction of the myocardium pumps blood out of the heart into the aorta and pulmonary trunk arteries.
Section of the heart wall animation slide 14
Section of the heart wall with the myocardium highlighted and the cardiac muscle fibers labelled.
The myocardium layer of the heart wall.
1
2
  1. Covering the inner surface of the heart wall is the image descriptionendocardium. This layer also covers the heart valves and tendons and is continuous with the endothelium that lines the major blood vessels that attach to the heart.
Section of the heart wall animation slide 14
A section of the heart wall with the endocardium highlighted and the areolar tissue layer, and squamous cell layer labelled.
The endocardium layer of the heart wall.
1
2

The endocardium is made up of thin layers of simple squamous cells and areolar tissue, similar to the epicardium. Secretions from the squamous cells help regulate the activity of the myocardium.

Test yourself:

Section of the heart wall: [image descriptionShow/image descriptionHide answers]

Test yourself image for the section of the heart wall with answers hidden.
Test yourself image of a section of the heart wall with answers shown: epicardium, myocardium, endocardium, Squamous cell layer, Areolar tissue layer, Cardiac muscle fibers, Areolar tissue layer, Squamous cell layer
Review the layers of the heart wall and test yourself.
1
2