Structure of the Heart

Location of where the heart is called

The mediastinum

Muscle of the heart is called

Myocardium

The muscle around the heart is the

Pericardium

Define intercalated discs

In between cardiac muscles, we will have regions that will allow neighboring cells to communicate with one another (like gap junctions)

The outermost layer of the heart muscle wall is the

Pericardium

what are the sections of the pericardium?

Parietal pericardium, pericardial cavity, visceral pericardium

List the layers that make up the parietal pericardium

Fibrous layer and serous layer

Define the function of the fibrous layer of the parietal pericardium? And what is it made of?

Dense fibrous mix of both regular and irregular connective tissue. Functions for cushioning and energy storage purposes.

Define the function of the serous layer of the parietal pericardium? What is it made of?

Simple squamous epithelial tissue. Functions to have a smooth layer for the blood cells.

what is found between the parietal pericardium and visceral pericardium?

Pericardial cavity

Define the visceral pericardium and its structure

Inner most layer of the pericardium consisting of 2 layers, the serous and the fibrous layer

Define the serous layer and its function of the visceral pericardium

1. simple squamous epithelia. This is going to be facing the parietal layer of the parietal pericardium. Both facing each other and being simple squamous epithelia. 

What is the fibrous layer of the visceral pericardium made of?

Areolar connective tissue

The thickest section of the structure of the heart is called the

Myocardium

This structure divides the left and right sides of the heart

Cardiac septum

Define the endocardium

The inner most lining of the heart, made up of two layers. The subendothelium and the endothelium

Define the subendothelium of the endocardium

1. areolar CT

   • To provide nutrients to the endothelium, so the endothelium can keep a smooth surface and prevent blood clots. 

Define the endothelium of the endocardium

1. simple squamous CT. It provides a smooth surface, allowing the blood to be in contact with the heart with a  smooth surface. 

   • To prevent blood clot and damage to the blood cells

These structures are found between two different chambers

valves

The purpose of valves

Is to ensure unidirectional flow of the blood, moving it forward

Define chordae tendonae

• Atrioventricular valves need support made of dense regular CT. They are going to pull on the atrioventricular valves, so they 1) open in the correct direction and 2) are going to resist prolapsing of the valves. Prolapse means opening from the opposite way/direction. 

  • Dense regular CT 

What is the function of chordae tendonae?

To keep the valves closed

Define papillary muscles

Contractile units able to pull on the chordae tendonae