3.2.5 The Mammalian Heart

Question 1

Heart Structure

Answer 1

The human heart has a mass of around 300g and is roughy the size of a closed fist
The heart is a hollow, muscular organ located in the chest cavity
It is protected in the chest cavity by the pericardium, a tough and fibrous sac
The heart is divided into 4 chambers
- the top 2 chambers are the atria and the bottom 2 chambers are ventricles
The left and right sides of the heart are separated by a wall of the muscular tissue, called the septum
- the portion of the septum which separates the left and right atria is called the interatrial septum, while the the portion of the septum which separates the left and right ventricles is called the interventricular septum
The septum is very important for ensuring blood doesn’t mix between the left and right sides of the heart

Question 2

Valves in the Heart

Question 3

Coronary Arteries