The circulatory system.
the liver,the kidneys,and the heart.
Your breathing system plus the heart edf
The heart cell structure is just like most body cells. It is different in the way it works. It shows autorhythmisty as they beat on their own without nervous system stimulation.
the hard structure protects your nervous system from getting damagedYour skeleton protects your nervous system by providing a sort of helmet for your brain. This helmet is called your skull and it helps keep the most important part of your nervous system safe.
two kidneys, two ureters, bladder, urethra
The most important part of the Circulatory Sytem is the capillaries.
It gets blood across all of you heart.
The heart is part of the cardio-vascular system. It is the most important part of the system since the heart is a pump which regulates the flow of blood through all the vasculature. Without the heart, blood vessels would simply become useless, empty tubes.
Skeletal muscle pump
It helps protect some of our most vital organs such as our heart and lungs.
The most important part of the heart is all of it. There all equally as important.
The correct order from least to most complex is: heart cell, cardiac muscle, heart, circulatory system. A heart cell is the basic unit of structure and function, which combines to form cardiac muscle. The heart is an organ made up of cardiac muscle, and the circulatory system encompasses the heart along with blood vessels and blood, facilitating the transport of nutrients and oxygen throughout the body.