The part of anatomy that internally divides the thoracic cavity from the abdominal cavity is the

a. mediastinum
b. umbilicus
c. viscera
d. diaphragm.

The  diaphragm is the part of anatomy that internally divides the thoracic cavity from the abdominal cavity. It separates the thoracic cavity, that where the heart and the lungs is located, from the abdominal cavity that contains many organs such as the stomach, liver, gallbladder and kidneys. 

What is the difference between cytokinesis in plant and animal cells? animal cells dived by a cleavage furrow. plant cells divide by a cell plate that eventually becomes the cell wall. cytoplasm and cell membranes are necessary for cytokinesis in both plant and animals.